Immortalization Of Epithelial Cells Research Articles

The role of heparan sulfate in enhancing the chemotherapeutic response in triple-negative breast cancer

BackgroundBreast cancer, one of the most common forms of cancer, is associated with the highest cancer-related mortality among women worldwide. In comparison to other types of breast cancer, patients diagnosed with the triple-negative breast cancer (TNBC) subtype have the worst outcome because current therapies do not produce long-lasting responses. Hence, innovative therapies that produce persisting responses are a critical need. We previously discovered that hyperactivating purinergic receptors (P2RXs) by increasing extracellular adenosine triphosphate (eATP) concentrations enhances TNBC cell lines’ response to chemotherapy. Heparan sulfate inhibits multiple extracellular ATPases, so it is a molecule of interest in this regard. In turn, heparanase degrades polysulfated polysaccharide heparan sulfate. Importantly, previous work suggests that breast cancer and other cancers express heparanase at high levels. Hence, as heparan sulfate can inhibit extracellular ATPases to facilitate eATP accumulation, it may intensify responses to chemotherapy. We postulated that heparanase inhibitors would exacerbate chemotherapy-induced decreases in TNBC cell viability by increasing heparan sulfate in the cellular microenvironment and hence, augmenting eATP.MethodsWe treated TNBC cell lines MDA-MB 231, Hs 578t, and MDA-MB 468 and non-tumorigenic immortal mammary epithelial MCF-10A cells with paclitaxel (cytotoxic chemotherapeutic) with or without the heparanase inhibitor OGT 2115 and/or supplemental heparan sulfate. We evaluated cell viability and the release of eATP. Also, we compared the expression of heparanase protein in cell lines and tissues by immunoblot and immunohistochemistry, respectively. In addition, we examined breast-cancer-initiating cell populations using tumorsphere formation efficiency assays on treated cells.ResultsWe found that combining heparanase inhibitor OGT 2115 with chemotherapy decreased TNBC cell viability and tumorsphere formation through increases in eATP and activation of purinergic receptors as compared to TNBC cells treated with single-agent paclitaxel.ConclusionOur data shows that by preventing heparan sulfate breakdown, heparanase inhibitors make TNBC cells more susceptible to chemotherapy by enhancing eATP concentrations.

The role and mechanism of circadian clock gene BMAL1 in the proliferation and metastasis of nasopharyngeal carcinoma by inhibition TGF-β1/Smads pathway.

6027 Background: To explore the molecular mechanism of biological clock gene BMAL1 inhibiting the proliferation and metastasis of nasopharyngeal carcinoma(NPC). Methods: 1. IHC detected the expression of BMAL1 in 41 cases of nasopharyngeal chronic inflammatory tissue and 71 cases of NPCtissue. PCR and Western blot measured the expression levels of BMAL1 in NP69 in NPC cells and human immortalized nasopharyngeal epithelial cells, respectively. 2. To detect the effect of BMAL1 on the proliferation capacity of NPCcells in vitro and in vivo; Scratch healing and Transwell invasion migration experiments detected the effect of BMAL1 on the invasion and migration ability of NPCcells in vitro. Fluorescence in vivo imaging and HE staining to determine the transfer of nude mouse tail intravenous injection model. PCR and Western blot detect the effect of BMAL1 on the expression of EMT-related markers at the transcriptional and protein levels in NPC cells. 3. A series of molecular biological means such as bioinformatics technology, ChIP experiment, double luciferase reporter gene experiment, immunofluorescence colocalization experiment and Co-IP were used to verify its mechanism. Results: 1. The expression of BMAL1 in NPCtissues and cells is reduced. The expression of BMAL1 in NPC tissues was associated with the M stage of nasopharyngeal carcinoma patients (p=0.006). 2. Overexpression of BMAL1 can inhibit the proliferation, invasion and migration ability of nasopharyngeal cancer cells, while knocking down BMAL1 is the opposite. Overexpression of BMAL1 inhibits EMT of NPCcells. 3. There are 5 BMAL1 binding sites in the TGF-β1promoter region, and BMAL1 can directly bind to the TGF-β1promoter region, which can inhibit the transcriptional activity of TGF-β1. Overexpression of BMAL1 inhibits TGF-β1/Smads pathway activity. Under the induction of recombinant human TGF-β1, the proliferation ability of NPC cells was enhanced, the activity of TGF-β1/Smads signaling pathway was enhanced, and nasopharyngeal cancer cells underwent EMT, and cell invasion and migration capacity increased. After overexpression of BMAL1, TGF-β1 no longer promotes TGF-β1/Smads signaling pathway activity, EMT is inhibited, and cell invasion and migration ability is weakened. BMAL1 combined with TGF-β1 has certain diagnostic value in predicting whether nasopharyngeal carcinoma metastasis. Conclusions: BMAL1 expression is downregulated in nasopharyngeal carcinoma, and its expression level is related to the development and metastasis of nasopharyngeal carcinoma. BMAL1 can inhibit the proliferation, epithelial-mesenchymal transformation and invasion and metastasis ability of NPC cells, and its mechanism is related to the inhibition of TGF-β1/Smads signaling pathway activity. It is speculated that it may become a new prognostic marker and therapeutic target for nasopharyngeal carcinoma.

Effect of human H3N2 influenza virus reassortment on influenza incidence and severity during the 2017–18 influenza season in the USA: a retrospective observational genomic analysis

During the 2017-18 influenza season in the USA, there was a high incidence of influenza illness and mortality. However, no apparent antigenic change was identified in the dominant H3N2 viruses, and the severity of the season could not be solely attributed to a vaccine mismatch. We aimed to investigate whether the altered virus properties resulting from gene reassortment were underlying causes of the increased case number and disease severity associated with the 2017-18 influenza season. Samples included were collected from patients with influenza who were prospectively recruited during the 2016-17 and 2017-18 influenza seasons at the Johns Hopkins Hospital Emergency Departments in Baltimore, MD, USA, as well as from archived samples from Johns Hopkins Health System sites. Among 647 recruited patients with influenza A virus infection, 411 patients with whole-genome sequences were available in the Johns Hopkins Center of Excellence for Influenza Research and Surveillance network during the 2016-17 and 2017-18 seasons. Phylogenetic trees were constructed based on viral whole-genome sequences. Representative viral isolates of the two seasons were characterised in immortalised cell lines and human nasal epithelial cell cultures, and patients' demographic data and clinical outcomes were analysed. Unique H3N2 reassortment events were observed, resulting in two predominant strains in the 2017-18 season: HA clade 3C.2a2 and clade 3C.3a, which had novel gene segment constellations containing gene segments from HA clade 3C.2a1 viruses. The reassortant re3C.2a2 viruses replicated with faster kinetics and to a higher peak titre compared with the parental 3C.2a2 and 3C.2a1 viruses (48 h vs 72 h). Furthermore, patients infected with reassortant 3C.2a2 viruses had higher Influenza Severity Scores than patients infected with the parental 3C.2a2 viruses (median 3·00 [IQR 1·00-4·00] vs 1·50 [1·00-2·00]; p=0·018). Our findings suggest that the increased severity of the 2017-18 influenza season was due in part to twointrasubtypes, cocirculating H3N2 reassortant viruses with fitness advantages over the parental viruses. This information could help inform future vaccine development and public health policies. The Center of Excellence for Influenza Research and Response in the US, National Science and Technology Council, and Chang Gung Memorial Hospital in Taiwan.

Abstract NG03: Functional and computational approaches to uncover selection advantages of cancer aneuploidy

Abstract Aneuploidy, including the gain or loss of whole chromosomes or chromosome arms, is a near-universal feature of cancer. We previously applied methods that define chromosome arm aneuploidy to over 10,000 tumors in the Cancer Genome Atlas (TCGA). Cancer subtypes are often characterized by tumor specific patterns of chromosome arm copy number alterations and breakpoints; for example, squamous cell carcinomas (SCCs) from different tissues of origin are characterized by chromosome 3p (chr3p) loss and chromosome 3q (chr3q) gain. From the TCGA aneuploidy data, we developed an algorithm called BISCUT to distinguish peak regions of aneuploidy breakpoints on each chromosome arm. BISCUT identified loci affected by broad copy number alterations that provide fitness advantages or disadvantages both within individual cancer types and across cancers. Our analyses are consistent with selection being the primary driver of aneuploidy events in cancer. We next wanted to validate some BISCUT peaks without a known driver, to identify potential gene deletions that are beneficial in cancer cells. We focused on chromosome 8p (chr8p), as this arm is frequently deleted across cancer types, but no strong tumor suppressors have been identified. Recent advances in genome engineering allow generation of large chromosomal alterations and validation of findings from patient genomic data. For this study, we used our CRISPR-Cas9 arm-deletion system to delete chr8p in human immortalized epithelial cells. Cells with chr8p deletion showed lower amounts of cell death in culture. Knockdown of WRN, one of the two genes in the smallest chr8p BISCUT peak, was sufficient to reproduce this phenotype, suggesting that WRN haploinsufficiency may be beneficial to tumor development. As aneuploidy occurs in tissue-specific patterns, we also wanted to explore the role of chr3 arm aneuploidies in squamous cancers. We again used the CRISPR-Cas9 system to delete one copy of chr3p in a human immortalized lung epithelial cell line similar to the putative cell-of-origin in lung SCC. Consistent with patient data, expression of chr3p genes was decreased upon deletion, as well as increased expression of interferon response genes. Cells with chr3p deletion initially proliferated more slowly than their siblings. Interestingly, after several passages in culture, this proliferation defect was rescued in chr3p deleted cells. Genome sequencing and karyotype analyses suggested that this was partially the result of chr3 duplication, with cells transitioning to a state of chr3q gain. Culturing these cells as organoids also demonstrated that chr3p deletion and chr3q gain can affect basal cell differentiation, consistent with their high frequency in squamous cancers. Our genome engineering approach to model chromosome arm aneuploidies provides a robust model to validate drivers from aneuploidy events, which will be critical to address the gap in our understanding of aneuploidy in cancer. In addition, our methods have identified consequences of individual aneuploidy events, which will lead to new precision oncology targets for patients. Citation Format: Alison M. Taylor. Functional and computational approaches to uncover selection advantages of cancer aneuploidy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr NG03.

A metabolic map and artificial intelligence-aided identification of nasopharyngeal carcinoma via a single-cell Raman platform.

Nasopharyngeal carcinoma (NPC) is a complex cancer influenced by various factors. This study explores the use of single-cell Raman spectroscopy as a potential diagnostic tool for investigating biomolecular changes associated with NPC carcinogenesis. Seven NPC cell lines, one immortalised nasopharyngeal epithelial cell line, six nasopharyngeal mucosa tissues and seven NPC tissue samples were analysed by performing confocal Raman spectroscopic measurements and imaging. The single-cell Raman spectral dataset was used to quantify relevant biomolecules and build machine learning classification models. Metabolomic profiles were investigated using ultra-performance liquid chromatography-tandem mass spectrometer (UPLC-MS/MS). By generating a metabolic map of seven NPC cell lines, we identified an interplay of altered metabolic processes involving nucleic acids, amino acids, lipids and sugars. The results from spatially resolved Raman maps and UPLC-MS/MS metabolomics were consistent, revealing an increase of unsaturated fatty acids in cancer cells, particularly in highly metastatic 5-8F and poorly differentiated CNE2 cells. The classification model achieved a nearly perfect classification when identifying NPC and non-NPC cells with an ROC-AUC of 0.99 and a value of 0.97 when identifying 13 tissue samples. This study unveils a complex interplay of metabolic network and highlights the potential roles of unsaturated fatty acids in NPC progression and metastasis. This renders further research to provide deeper insights into NPC pathogenesis, identify new metabolic targets and improve the efficacy of targeted therapies in NPC. Artificial intelligence-aided analysis of single-cell Raman spectra has achieved high accuracies in the classification of both cancer cells and patient tissues, paving the way for a simple, less invasive and accurate diagnostic test.

Persistent infection with Porphyromonas gingivalis increases the tumorigenic potential of human immortalised oral epithelial cells through ZFP36 inhibition.

The association between Porphyromonas gingivalis infection and oral squamous cell carcinoma (OSCC) has been established by numerous epidemiological studies. However, the underlying mechanism specific to this connection remains unclear. By bioinformatical analysis, we identified ZFP36 as a potentially significant co-expressed gene in both the OSCC gene database and the persistent infection model of P. gingivalis. To further investigate the role of ZFP36, we established a cell model that human immortalized oral epithelial cells (HIOECs) that were sustainedly infected by P. gingivalis (MOI = 1) for a duration of 30 weeks. Our findings indicated that sustained infection with P. gingivalis inhibited the expression of ZFP36 protein and induced changes in the biological behaviour of HIOECs. The mechanism investigation demonstrated the potential role of ZFP36 in regulating the cancer-related biological behaviour of HIOECs. Subsequent studies revealed that highly expressed CCAT1 could serve as a molecular scaffold in the formation of the ZFP36/CCAT1/MK2 complex. This complex formation enhanced the binding abundance of MK2 and ZFP36, thereby promoting the inhibition of ZFP36 protein phosphorylation. To summarize, low expression of ZFP36 protein under persistent P. gingivalis infection enhances the cancer-related biological behaviour of HIOECs.

The mitotic checkpoint kinase BUB1 is a direct and actionable target of MYB in adenoid cystic carcinoma.

Adenoid cystic carcinoma (ACC) is a head and neck cancer that frequently originates in salivary glands, but can also strike other exocrine glands such as the breast. A key molecular alteration found in the majority of ACC cases is MYB gene rearrangements, leading to activation of the oncogenic transcription factor MYB. In this study, we used immortalised breast epithelial cells and an inducible MYB transgene as a model of ACC. Molecular profiling confirmed that MYB-driven gene expression causes a transition into an ACC-like state. Using this new cell model, we identified BUB1 as a targetable kinase directly controlled by MYB, whose pharmacological inhibition caused MYB-dependent synthetic lethality, growth arrest and apoptosis of patient-derived cells and organoids.

Integrated bioinformatics approaches to investigate alterations in transcriptomic profiles of monkeypox infected human cell line model

BackgroundThe recent re-emergence of the monkeypox (mpox) epidemic in nonendemic regions has raised concerns regarding a potential global outbreak. The mpox virus (MPV) is a smallpox-like virus belonging to the genus Orthopoxvirus (family: Poxviridae). Although studies suggest that MPV infection suppresses the Toll-like receptor-3- and tumor necrosis factor-α-related signaling pathways, whether MPV regulates other immune-related pathways remains unclear. MethodsIn this study, two distinct temporal patterns were used for establishing an MPV-infected human immortal epithelial cancer cell line (HeLa). These two durations 2 and 12 h of incubation were selected to identify the coregulated genes and pathways affected by MPV infection. ResultsThe use of the Gene Ontology framework, Kyoto Encyclopedia of Genes and Genome database, and MetaCore software yielded valuable insights. Specifically, various pathways were found to be enriched in HeLa cells infected with MPV for 2 and 12 h. These pathways included Notch, CD40, CD95, hypoxia-inducible factor-1-α, interleukin (IL)− 1, IL-6, phosphoinositide 3-kinase, nuclear factor-κB, mitogen-activated protein kinase, and oxidative stress–induced signalling pathways. Clusters and pathways of metabolism and viral replication cycles were significantly associated with the 2-hour infection group. This association was identified based on the regulation of genes such as HSPG2, RHPN2, MYL1, ASPHD2, CA9, VIPR1, SNX12, MGC2752, SLC25A1, PEX19, and AREG. Furthermore, clusters and pathways related to immunity and cell movement were found to be associated with the 12-hour infection group. This association was identified based on the regulation of genes such as C1orf21, C19orf48, HRK, IL8, GULP1, SCAND2, ATP5C1, FEZ1, SGSH, TACC2, CYP4X1, MMP1, CPB1, P2RY13, WDR27, PRPF4, and ENDOD1. ConclusionsThis study can improve our understanding of the mechanisms underlying the pathophysiology and post-infection sequelae of mpox. Our findings provide valuable insights into the various modes of MPV infection.

Biological and clinical significance of the YKL-40/osteopontin-integrin β4-p70S6K axis induced by macrophages in early oesophageal squamous cell carcinoma.

M2 macrophages contribute to the progression of oesophageal squamous cell carcinoma (ESCC); however, the roles of M2 macrophages in early ESCC remain unclear. To clarify the biological mechanisms underlying the interaction between M2 macrophages and oesophageal epithelial cells in early-stage ESCC, in vitro co-culture assays between the immortalised oesophageal epithelial cell line Het-1A and cytokine-defined M2 macrophages were established. Co-culture with M2 macrophages promoted the proliferation and migration of Het-1A cells via the mTOR-p70S6K signalling pathway activated by YKL-40, also known as chitinase 3-like 1, and osteopontin (OPN) that were hypersecreted in the co-culture supernatants. YKL-40 and OPN promoted the above phenotypes of Het-1A by making a complex with integrin β4 (β4). Furthermore, YKL-40 and OPN promoted M2 polarisation, proliferation, and migration of macrophages. To validate the pathological and clinical significances of in vitro experimental results, immunohistochemistry of human early ESCC tissues obtained by endoscopic submucosal dissection (ESD) was performed, confirming the activation of the YKL-40/OPN-β4-p70S6K axis in the tumour area. Moreover, epithelial expression of β4 and the number of epithelial and stromal infiltrating YKL-40- and OPN-positive cells correlated with the Lugol-voiding lesions (LVLs), a well-known predictor of the incidence of metachronous ESCC. Furthermore, the combination of high expression of β4 and LVLs or high numbers of epithelial and stromal infiltrating YKL-40- and OPN-positive immune cells could more clearly detect the incidence of metachronous ESCC than each of the parameters alone. Our results demonstrated that the YKL-40/OPN-β4-p70S6K axis played important roles in early-stage ESCC, and the high expression levels of β4 and high numbers of infiltrating YKL-40- and OPN-positive immune cells could be useful predictive parameters for the incidence of metachronous ESCC after ESD. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Abstract 1214: Establishment and characterization of reversibly immortalized endometrial and ovarian epithelial cell lines using Sendai virus

Abstract Objective: We aimed to establish reversibly immortalized cell lines from human uterine and ovary cells using the Sendai virus (SeV) vector. The immortalized cells derive from normal and benign ovarian epithelial cells and endometrial epithelial cells. Furthermore, we sought to elucidate the mechanisms of carcinogenesis using the immortalized cell lines. Methods: Cells were collected at the time of surgery after obtaining patient consent. The cells used in this study were as follows: ovarian epithelial cells (normal epithelium, Ov n; normal epithelium with germline BRCA1 or BRCA2 mutation, Ov BRCA1 2; ovarian endometrioma, Ov endo; mucinous cystadenoma; Ov m), normal fallopian tube (FT) cells, and endometrial epithelium (normal epithelium, Em n). These cells were infected with temperature-sensitive SeV vectors carrying three immortalization genes, Bmi-1, hTERT, and SV40T.The presence of infection was confirmed through Green Fluorescent Protein (GFP) and Orange Fluorescent Protein (OFP). Immunoreactivity to the anti-human EpCAM antibody (a marker derived from epithelial carcinoma) in each SeV-infected cell was confirmed through flow cytometry. QH and multicolor FISH staining were performed for karyotyping of metaphase chromosomes in each cell line to determine chromosome number and structural abnormalities. Human transcriptome sequencing analysis was performed with NovaSeq 6000 (Illumina) using total RNA from each cell line. Some genes that showed significant expression in each cell line were subjected to real-time PCR (RT-PCR). Results: We established the immortalized cell lines from human uterine and ovarian tissues. SeV-infected cells exhibited GFP and OFP fluorescence, while non-infected cells did not. SeV infection allowed all primary cell lines to grow for 25 or more passages, while non-infected SeV cells lacked the proliferative capacity and showed senescence-like morphology. SeV-infected cells senesced in a temperature-dependent manner. Ov n SeV- infected cells ion causedshowed a small increase in chromosome structural abnormalities. But, Ov BRCA1 and 2 SeV-infected cells showed larger than thatand . Llong-term passaged cells did not show immune response to anti-human EpCAM antibodies in normal cells. Eleven Three genes were predominantly expressed in Ov BRCA1 and Ov BRCA2 cells and were not expressed in Ov n cells. SomeTwo out of ththe three genesem were found to be predominantly expressed in Ov endo cells compared to the expression in the Ovn cell line. Furthermore, RT-PCR results also indicated substantially higher expression of two genes in Ov BRCA1/2 cells and in Ov endo cells compared to the expression in Ov n cells. Conclusion: We succeeded in the reversible immortalization of endometrial and ovarian epithelial cells by using SeV infection. We identified several candidate genes that may be involved in the oncogenic mechanism of ovarian cancer associated with endometriosis or germline BRCA1 and BRCA2. Citation Format: Masayo Okawa, Hiroaki Komatsu, Kohei Hikino, Yuki Iida, Masayo Hosokawa, Mayumi Sawada, Akiko Kudoh, Jun Chikumi, Shinya Sato, Genki Hichiwa, Yasuhiro Kazuki, Kanako Kazuki, Fuminori Taniguchi, Mitsuo Oshimura, Tasuku Harada. Establishment and characterization of reversibly immortalized endometrial and ovarian epithelial cell lines using Sendai virus [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1214.

Abstract 397: The role of heparan sulfate in enhancing the chemotherapeutic response in triple-negative breast cancer

Abstract Among women worldwide, breast cancer has the highest incidence and is the leading cause of cancer-related death. Patients with the triple-negative breast cancer (TNBC) subtype have an inferior prognosis in comparison to other breast cancers because the current therapies do not facilitate long-lasting responses. Thus, there is a critical need for novel therapeutic strategies that induce stronger responses. In our previous research, we discovered that augmenting the concentration of extracellular ATP (eATP) greatly enhances the chemotherapeutic response of TNBC cell lines by activating purinergic receptors (P2RXs), leading to cell death through the induction of non-selective membrane permeability. However, eATP levels are limited by several classes of extracellular ATPases. One endogenous molecule of interest that can inhibit multiple classes of extracellular ATPases is heparan sulfate. Heparan sulfate itself is degraded by heparanase, an enzyme that is known to be highly expressed in various cancers, including breast cancer. Heparan sulfate has previously been shown to regulate several cancer-related processes such as fibroblast growth factor signaling, neoangiogenesis by sequestering vascular endothelial growth factors in the extracellular matrix, hedgehog signaling and cell adhesion. In this project, we identified an additional mechanism for a tumor suppressor role of heparan sulfate: inhibition of extracellular ATPases, leading to augmented levels of eATP. Several heparanase inhibitors have been previously identified, including OGT 2115, suramin, PI-88, and PG 545. We hypothesized that heparanase inhibitors would augment eATP concentrations in TNBC by increasing heparan sulfate in the tumor microenvironment, resulting in increased cell death in response to chemotherapy. We treated TNBC cell lines MDA-MB 231, Hs 578t, and MDA-MB 468 and non-tumorigenic immortal mammary epithelial MCF-10A cells with increasing concentrations of the chemotherapeutic agent paclitaxel in the presence of heparan sulfate and/or OGT 2115 with eATP content and cell viability being assessed. Moreover, to confirm that the effects of OGT 2115 are mediated through eATP, we utilized specific antagonists to the purinergic receptors P2RX4 and P2RX7. In addition, the protein expression of heparanase was compared in all the examined cell lines via Western blot analysis. We also evaluated the effects of this combination on the breast cancer-initiating cell population in the treated cells using flow cytometry and tumorsphere formation efficiency assays. These results demonstrate that inhibiting the degradation of heparan sulfate in the tumor microenvironment enhances the susceptibility of TNBC cell lines to chemotherapy by augmenting extracellular ATP concentrations. This strategy could potentially be used to induce deeper and more durable responses in triple-negative breast cancer patients. Citation Format: Jasmine M. Manouchehri, Jharna Datta, Mathew A. Cherian. The role of heparan sulfate in enhancing the chemotherapeutic response in triple-negative breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 397.

Abstract 398: The inhibition of sulfation of heparan sulfate augments the chemotherapeutic response in triple-negative breast cancer

Abstract The leading cause of cancer-related death among women worldwide is breast cancer. The triple-negative breast cancer (TNBC) subtype has limited therapeutic options that produce durable responses. As a result, it is associated with an especially poor prognosis compared to other breast cancer subtypes. Hence, the development of innovative therapeutic strategies that produce deeper and more durable responses is critically needed. We found that increasing extracellular ATP (eATP) can enhance the susceptibility of TNBC cell lines to chemotherapy through the activation of purinergic receptors (P2RXs) P2RX4 and P2RX7. However, eATP levels are limited by several different classes of eATPases, making the design of a single molecule that effectively inhibits all classes of eATPase complicated. Heparan sulfate, a carbohydrate moiety that is covalently linked to several cell surface and extracellular matrix proteins has previously been identified as an endogenous inhibitor of several classes of eATPases. Heparan sulfate is desulfated by sulfatases 1 and 2 at the 6-O-hydroxyl groups of glucosamine residues in heparan sulfate. Sulfatase 2 has been determined to be highly expressed in a variety of cancers including breast cancer, whereas sulfatase 1 is not. Several sulfatase inhibitors have been previously developed, such as OKN-007, which is a specific inhibitor of sulfatase 2. We hypothesized that OKN-007 would augment eATP levels in TNBC cell lines exposed to chemotherapy by increasing levels of heparan sulfate in the tumor microenvironment, leading to intensified cell death. TNBC cell lines MDA-MB 231, Hs 578t, and MDA-MB 468 and non-tumorigenic immortal mammary epithelial MCF-10A cells were treated with increasing concentrations of the chemotherapeutic agent paclitaxel in the presence of heparan sulfate and/or OKN-007, and eATP content and cell viability were evaluated. Inhibitors to the purinergic receptors P2RX4 and P2RX7 were used to further confirm that the mechanism of enhanced cell death induced by OKN-007 was through these receptors. In addition, basal protein and cell surface expression of sulfatases 1 and 2 were determined in all the examined cell lines via ELISA, Western blot, and flow cytometry analysis. To assess the effects on cancer-initiating cell properties, TNBC cell lines were treated with paclitaxel in the presence of heparan sulfate and/or OKN-007, and the tumorsphere formation efficiency assay used to assess for cancer-initiating cells. In parallel, we assessed for effects on cancer-initiating cells in treated cells using flow cytometry. Our results showed that inhibiting the 6-O desulfation of heparan sulfate increases eATP accumulation, thereby, enhancing TNBC cell lines’ response to chemotherapy. These findings may lead to therapies for TNBC based on sulfatase 2 inhibition that results in more effective responses with fewer side effects. Citation Format: Jasmine M. Manouchehri, Jharna Datta, Mathew A. Cherian. The inhibition of sulfation of heparan sulfate augments the chemotherapeutic response in triple-negative breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 398.

Abstract 4716: Characterization of 3D genome in nasopharyngeal carcinoma (NPC)

Abstract Background: Epstein-Barr virus (EBV) can be detected in more than 90% of NPC patients in Hong Kong. It has been shown that EBV infection could hijack the human epigenome in B cell lymphoma and EBV+ gastric cancer, however, the role of EBV in epigenetic dysregulation remains largely unknown in NPC. Recently, our epigenomic landscape study demonstrated EBV was associated with changes of chromatin accessibility in NPC, which were largely involved in the binding sites of CTCF, a master regulator of chromosome organization. Therefore, we aim to further characterize the 3D chromatin structure in NPC. Methods: We used the Hi-C (Omni-C Seq) to profile the chromatin interactions in the EBV-positive (EBV+) NPC, EBV-negative (EBV-) NPC, and normal immortalized epithelial (NPE) cell lines. The Omni-C Seq data were integrated with the ATAC-Seq, RNA-Seq, and CUT&RUN-Seq data. The histone markers including H3K4me3, H3K27ac, and H3K27me3, were applied to classify the active and inactive status of the chromatins. The chromatin looping and topologically associated domains (TADs) were defined by the CTCF binding sites. Results: We observed a much larger compartmentalization size in EBV+ NPC with a consistent increase of active to inactive (A to B) compartments, compared to NPE and EBV- NPC. Pathway enrichment analysis showed that these changes potentially influenced immune response, cell differentiation and development, metabolism, ERBB pathway, and calcium signaling transduction. In addition to the changes in compartmentalization, we observed a reduction of CTCF binding signals at the TADs boundaries and the loss of chromatin looping at the 10kb resolution. Consistently, the aggregate peak analysis has shown a significant reduction of the CTCF anchor, indicating the abandonment of architectural CTCF in EBV+ NPC. More importantly, we found EBV tethering to the host chromatins. In the EBV genome, the tethering sites were often located at the regions associated with OriP, EBNA1, and BARTs. In the human genome, the tethering sites were dramatically enriched in the inactive to active (B to A) compartments, which were highly associated with the enhancer regions with H3K27ac. We identified a specific target gene CD74 with EBV tethering at the nearby super-enhancer region. Our results suggest the upregulation of CD74 could be controlled via remodulating the host 3D genome in EBV+ NPC. The spatial transcriptome analysis indicated that the expression of CD74 was highly correlated with HLA-DRA. The spatial analysis further showed that the NPC patients with upregulated HLA-DRA often had de novo distant metastasis after treatment (p=0.007). Conclusions: The EBV tethering to the host genome has a significant impact on host 3D genome organization, affecting chromatin accessibility and gene regulation, providing survival advantages of cancer cell growth and potentially contributing to immune suppression and metastasis. Citation Format: Dittman Lai-Shun Chung, Larry Ka-Yue Chow, Wei Dai. Characterization of 3D genome in nasopharyngeal carcinoma (NPC). [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4716.

Abstract 5458: TONSL is an immortalizing oncogene of the chromosome 8q24.3 amplicon and new therapeutic target in breast cancer

Abstract Study of genomic aberrations leading to immortalization of epithelial cells has been technically challenging due to lack of an appropriate isogenic model system. To address this technical challenge, we utilized primary breast luminal epithelial cells propagated from healthy donors of different genetic ancestry and their hTERT-immortalized counterparts to identify functional gene expression changes associated with immortalization. We identified elevated expression of TONSL (Tonsoku Like, DNA Repair Protein) as one of the earliest events during immortalization. TONSL is located on chromosome 8q24.3 and amplified in ~20% of breast cancers with significantly higher amplification in metastatic tumors. TONSL forms a complex with FACT and MMS22L1 to modulate multiple cellular pathways including DNA replication, repair through homologous recombination (HR) and functions as a post replicative histone/chromatin reader. TONSL alone immortalized primary breast epithelial cells and increased telomerase activity. While TONSL overexpression alone was insufficient for neoplastic transformation, TONSL-immortalized primary cells modified to overexpress defined oncogenes generated estrogen receptor-positive adenocarcinomas in NSG mice. Analysis of breast tumor microarray with ~500 tumors revealed poor overall and progression free survival of patients with TONSL-overexpressing tumors. TONSL increased chromatin accessibility to pro-oncogenic transcription factors including NF-κB and limited access to the tumor suppressor p53. Most importantly, TONSL overexpression resulted in significant changes in the expression of genes associated with DNA repair hubs, including upregulation of several genes in HR and Fanconi Anemia pathways. Consistent with the effects of TONSL on HR-associated genes, TONSL overexpressing primary cells exhibited upregulated DNA repair via HR. Moreover, TONSL was an essential gene for growth of TONSL-amplified breast cancer cell lines in vivo. Breast cancer cell lines with TONSL/chr8q24.3 amplification were sensitive to TONSL-FACT complex inhibitor CBL0137, both in vitro and in vivo. To our knowledge, TONSL is the only gene other than telomerase with immortalizing function and represents a new therapeutic target for breast cancer with chr8q24.3 amplification. Citation Format: Aditi S. Khatpe, Rebecca Dirks, Poornima Bhat-Nakshatri, Henry Mang, Katie Batic, Sarah Swiezy, Jacob Olson, Xi Rao, Yue Wang, Hiromi Tanaka, Sheng Liu, Jun Wan, Duojiao Chen, Yunlong Liu, Fang Fang, Sandra Althouse, Emily Hilsey, Maggie M. Granatir, Rebekah Addison, Constance J. Temm, George Sandusky, Audrey Lee-Gosselin, Kenneth Nephew Nephew, Kathy D. Miller, Harikrishna Nakshatri. TONSL is an immortalizing oncogene of the chromosome 8q24.3 amplicon and new therapeutic target in breast cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5458.

Polymorphism of E6 and E7 Genes in Human Papillomavirus Types 31 and 33 in Northeast China.

Persistent infection with human papillomavirus (HPV) types 31 and 33 is an important causative factor for cervical cancer. The E6/E7 genes are key oncogenes involved in the immortalization and transformation of human epithelial cells. Genetic polymorphism may lead to differences in the virus' carcinogenic potential, the immune reaction of the host, and the potencies of vaccines. Few studies on HPV31/33 E6/E7 genetic polymorphism have been carried out. To study the genetic polymorphism of HPV31 and HPV33 E6/E7 genes in northeast China, these genes (HPV31 E6/E7, n = 151; HPV33 E6/E7, n = 136) were sequenced and compared to reference sequences (J04353.1, M12732.1) using BioEdit. Phylogenetic trees were constructed by the neighbor-joining method using MegaX. The diversity of the secondary structure was estimated using the PSIPred server. The positively selected sites were analyzed using PAML4.9. The major histocompatibility complex (MHC) class I and MHCII epitopes were predicted using the ProPred-I server and ProPredserver. B-cell epitopes were predicted using the ABCpred server. In the 151 HPV31E6 sequences, 25 (25/450) single-nucleotide mutations were found, 14 of which were synonymous mutations and 11 were nonsynonymous. In the 151 HPV31E7 sequences, 8 (8/297) nucleotide mutations were found, 3 of which were synonymous mutations and 5 were nonsynonymous. In the 136 HPV33E6 sequences, 17 (17/450) nucleotide mutations were observed, 7 of which were synonymous mutations and 10 were nonsynonymous. C14T/G (T5I/S) was a triallelic mutation. Finally, in the 136 HPV33E7 sequences, 9 (9/294) nucleotide mutations were observed, 3 of which were synonymous mutations and 6 were nonsynonymous. C134T/A (A45V/E) and C278G/A (T93S/N) were triallelic mutations. Lineage A was the most common lineage in both HPV31 and HPV33. In all of the sequences, we only identified one positively selected site, HPV33 E6 (K93N). Most nonsynonymous mutations were localized at sites belonging to MHC and/or B-cell predicted epitopes. Data obtained in this study should contribute to the development and application of detection probes, targeted drugs, and vaccines.

Lentivirus-Mediated Short Hairpin RNA for Follistatin Downregulation Suppresses Tumor Progression in Hypopharyngeal Carcinoma.

Follistatin (FST) inhibits the action of activin by interfering with the binding of activin to its receptor. Although the prognostic value of FST in various cancers has been investigated previously, studies rarely focused on hypopharyngeal carcinoma (HPC). In our study, the effect of FST expression on HPC tissues and cell lines was investigated. A total of 60 patients with HPC were recruited for this study. Levels of FST mRNA and protein were measured by quantitative polymerase chain reaction (PCR) and immunohistochemistry in HPC tissue samples and by qPCR in the HPC FaDu cells, as well as immortal nasopharyngeal epithelial cell line NP-69 cells. After silencing the FST expression in FaDu cells using lentivirus-mediated siRNA that was specific for FST mRNA, cell proliferation was determined by a Celigo assay. Tumor growth was monitored in nude mice and viability was determined by a methylthiazoletetrazolium assay. The ratio of cell cycle arrest and apoptosis was evaluated by flow cytometry. The colony formation ability was performed using Giemsa staining. In addition, wound healing and Transwell migration and invasion assays were performed for the analysis of cell motility. FST expression was significantly higher in human HPC tissue and FaDu cells than in normal tissue and NP-69 cells. A higher expression of FST in HPC samples was positively correlated with advanced tumors. Moreover, FST knockdown by shRNA significantly decreased cell growth, colony formation, migration and invasion. Furthermore, FST silencing increased the cell apoptosis percentage, and arrested cell cycle in the S phase in FaDu cells. In addition, FST silencing suppressed tumor growth in vivo. Our results indicated that the FST gene was associated with HPC progression and may serve as a potential therapeutic target for the treatment of HPC.

Folate derivatives, 5-methyltetrahydrofolate and 10-formyltetrahydrofolate, protect BEAS-2B cells from high glucose-induced oxidative stress and inflammation.

Folate (vitamin B9) and its biologically active derivatives are well-known antioxidant molecules protecting cells from oxidative degradation. The presence of high glucose, often found in diabetic patients, causes oxidative stress resulting in cellular stress and inflammatory injury. Cells in organs such as the lung are highly prone to inflammation, and various protective mechanisms exist to prevent the progressive disorders arising from inflammation. In the present study, the synthetic form of folate, i.e. folic acid, and active forms of folate, i.e. 5-methyltetrahydrofolate and 10-formyltetrahydrofolate, were evaluated for their antioxidant and antiinflammatory potential against high glucose (50 mM)–mediated oxidative stress and inflammation in BEAS-2B cells, an immortalised bronchial epithelial cell line. High glucose treatment showed a 67% reduction in the viability of BEAS-2B cells, which was restored to the viability levels seen in control cultures by the addition of active folate derivatives to the culture media. The DCFH-DA fluorometric assay was performed for oxidative stress detection. The high glucose–treated cells showed a significantly higher fluorescence intensity (1.81- and 3.8-fold for microplate assay and microscopic observation, respectively), which was normalised to control levels on supplementation with active folate derivatives. The proinflammatory NF-κB p50 protein expression in the active folate derivative–supplemented high glucose–treated cells was significantly lower compared to the folic acid treatment. In support of these findings, in silico microarray GENVESTIGATOR database analysis showed that in bronchiolar small airway epithelial cells exposed to inflammatory condition, folate utilization pathway genes are largely downregulated. However, the folate-binding protein gene, which encodes to the folate receptor 1 (FOLR1), is significantly upregulated, suggesting a high demand for folate by these cells in inflammatory situations. Supplementation of the active folate derivatives 5-methyltetrahydrofolate and 10-formyltetrahydrofolate resulted in significantly higher protection over the folic acid from high glucose–induced oxidative stress and inflammation. Therefore, the biologically active folate derivatives could be a suitable alternative over the folic acid for alleviating inflammatory injury-causing oxidative stress.Supplementary InformationThe online version contains supplementary material available at 10.1007/s11626-022-00691-w.

Augmentation of Extracellular ATP Synergizes With Chemotherapy in Triple Negative Breast Cancer.

IntroductionBreast cancer affects two million patients worldwide every year and is the most common cause of cancer-related death among women. The triple-negative breast cancer (TNBC) sub-type is associated with an especially poor prognosis because currently available therapies fail to induce long-lasting responses. Therefore, there is an urgent need to develop novel therapies that result in durable responses. One universal characteristic of the tumor microenvironment is a markedly elevated concentration of extracellular adenosine triphosphate (eATP). Chemotherapy exposure results in further increases in eATP through its release into the extracellular space of cancer cells via P2RX channels. eATP is degraded by eATPases. Given that eATP is toxic to cancer cells, we hypothesized that augmenting the release of eATP through P2RX channels and inhibiting extracellular ATPases would sensitize TNBC cells to chemotherapy.MethodsTNBC cell lines MDA-MB 231, Hs 578t and MDA-MB 468 and non-tumorigenic immortal mammary epithelial MCF-10A cells were treated with increasing concentrations the chemotherapeutic agent paclitaxel in the presence of eATPases or specific antagonists of P2RXs with cell viability and eATP content being measured. Additionally, the mRNA, protein and cell surface expressions of the purinergic receptors P2RX4 and P2RX7 were evaluated in all examined cell lines via qRT-PCR, western blot, and flow cytometry analyses, respectively.ResultsIn the present study, we observed dose-dependent declines of cell viability and increases in eATP of paclitaxel-treated TNBC cell lines in the presence of inhibitors of eATPases, but not of the MCF-10A cell line. These effects were reversed by specific antagonists of P2RXs. Similar results, as those observed with eATPase inhibitors, were seen with P2RX activators. All examined cell lines expressed both P2RX4 and P2RX7 at the mRNA, protein and cell surface levels.ConclusionThese results reveal that eATP modulates the chemotherapeutic response in TNBC cell lines, which could be exploited to enhance the efficacy of chemotherapy regimens for TNBC.

Cigarette smoking is a secondary cause of folliculin loss

BackgroundBirt-Hogg-Dubé syndrome (BHD) is a clinical syndrome manifesting with cystic lung disease and pneumothorax. Features of BHD result from the loss-of-function mutations of the folliculin (FLCN) gene. Chronic obstructive pulmonary...

Establishment and characterization of a sheep endometrial epithelial cell line

Endometrial epithelial cells play a significant role in the "dialogue" between the embryo and the mother, but in vitro studies to clarify this are hampered by the limited lifespan of primary cells. As such, it is necessary to develop an in vitro model to study endometrial function. Morphological analysis showed that the pEECs were homogeneous, formed characteristic cobblestone monolayers, and expressed the epithelial cell-specific marker, cytokeratin 18. The isolated and purified cells were transfected with a plasmid encoding human telomerase reverse transcriptase (TERT) gene, pCI-neo-TERT, to establish an immortal endometrial epithelial cell line (iEECs). The transfected cells were cultured with G418 and monoclonal cells were selected for expanded culture. Expression of TERT mRNA was detected by RT-qPCR and protein was quantitated by Western blot. TERT expression was stable and continued to be active with no signs of aging. Assays for cell proliferation and apoptosis indicated higher proliferation and cellular activity in iEECs than pEECs. After stimulated by interferon tau (IFN-τ), both iEECs and pEECs showed similar upregulation levels in all the underlying genes. Taken together, these findings demonstrate that iEECs retained the basic morphology and function of pEECs, providing a robust in vitro model for study of the function of ovine endometrial epithelial cells.