Nucleus Of Cancer Cells Research Articles

Nasopharyngeal carcinoma cell screening based on nuclear targeting Surface-Enhanced Raman Scattering (SERS) detection

BackgroundNasopharyngeal carcinoma (NPC) is a malignant epithelial carcinoma arising from the nasopharyngeal mucosal lining. Diagnosis of NPC at early stage can improve the outcome of patients and facilitate reduction in cancer mortality. The most significant change between cancer cells and normal cells is the variation of cell nucleus. Therefore, accurately detecting the biochemical changes in nucleus between cancer cells and normal cells has great potential to explore diagnostic molecular markers for NPC. Highly sensitive surface-enhanced Raman scattering (SERS) could reflect the biochemical changes in the process of cell cancerization at the molecular level. However, rapid nuclear targeting SERS detection remains a challenge. ResultsA novel and accurate nuclear-targeting SERS detection method based on electroporation was proposed. With the assistance of electric pulses, nuclear-targeting nanoprobes were rapidly introduced into different NPC cells (including CNE1, CNE2, C666 cell lines) and normal nasopharyngeal epithelial cells (NP69 cell line), respectively. Under the action of nuclear localization signaling peptides (NLS), the nanoprobes entering cells were located to the nucleus, providing high-quality nuclear SERS signals. Hematoxylin and eosin (H&E) staining and in situ cell SERS imaging confirmed the excellent nuclear targeting performance of the nanoprobes developed in this study. The comparison of SERS signals indicated that there were subtle differences in the biochemical components between NPC cells and normal nasopharyngeal cells. Furthermore, SERS spectra combined with principal component analysis (PCA) and linear discriminant analysis (LDA) were employed to diagnose and distinguish NPC cell samples, and high sensitivity, specificity, and accuracy were obtained in the screening of NPC cells from normal nasopharyngeal epithelial cells. SignificanceTo the best of our knowledge, this is the first study that employing nuclear-targeting SERS testing to screen nasopharyngeal carcinoma cells. Based on the electroporation technology, nanoprobes can be rapidly introduced into living cells for intracellular biochemical detection. Nuclear-targeting SERS detection can analyze the biochemical changes in the nucleus of cancer cells at the molecular level, which has great potential for early cancer screening and cytotoxicity analysis of anticancer drugs.

Cell surface CD55 traffics to the nucleus leading to cisplatin resistance and stemness by inducing PRC2 and H3K27 trimethylation on chromatin in ovarian cancer

BackgroundPlatinum resistance is the primary cause of poor survival in ovarian cancer (OC) patients. Targeted therapies and biomarkers of chemoresistance are critical for the treatment of OC patients. Our previous studies identified cell surface CD55, a member of the complement regulatory proteins, drives chemoresistance and maintenance of cancer stem cells (CSCs). CSCs are implicated in tumor recurrence and metastasis in multiple cancers.MethodsProtein localization assays including immunofluorescence and subcellular fractionation were used to identify CD55 at the cell surface and nucleus of cancer cells. Protein half-life determinations were used to compare cell surface and nuclear CD55 stability. CD55 deletion mutants were generated and introduced into cancer cells to identify the nuclear trafficking code, cisplatin sensitivity, and stem cell frequency that were assayed using in vitro and in vivo models. Detection of CD55 binding proteins was analyzed by immunoprecipitation followed by mass spectrometry. Target pathways activated by CD55 were identified by RNA sequencing.ResultsCD55 localizes to the nucleus of a subset of OC specimens, ascites from chemoresistant patients, and enriched in chemoresistant OC cells. We determined that nuclear CD55 is glycosylated and derived from the cell surface pool of CD55. Nuclear localization is driven by a trafficking code containing the serine/threonine (S/T) domain of CD55. Nuclear CD55 is necessary for cisplatin resistance, stemness, and cell proliferation in OC cells. CD55 S/T domain is necessary for nuclear entry and inducing chemoresistance to cisplatin in both in vitro and in vivo models. Deletion of the CD55 S/T domain is sufficient to sensitize chemoresistant OC cells to cisplatin. In the nucleus, CD55 binds and attenuates the epigenetic regulator and tumor suppressor ZMYND8 with a parallel increase in H3K27 trimethylation and members of the Polycomb Repressive Complex 2.ConclusionsFor the first time, we show CD55 localizes to the nucleus in OC and promotes CSC and chemoresistance. Our studies identify a therapeutic mechanism for treating platinum resistant ovarian cancer by blocking CD55 nuclear entry.

Abstract PO4-01-08: Co-expression of estrogen receptor (ER), progesterone receptor (PR), and Ki67 in a single breast cancer cell indicates a favorable prognosis in ER-positive breast cancer

Abstract Background: ER-positive breast cancer is biologically and clinically divided into two subtypes: luminal-A and luminal-B. This classification is mainly based on the status of cellular proliferation. At least two different pathways drive cellular proliferation in ER-positive breast cancer. One is a classical pathway where ER binds to estrogen responsive element (ERE), which leads to the expression of downstream molecules, including PR. The other is a non-classical pathway where a complex of ER and relevant factors bind to different sites than ERE. Growth factor signaling has been suggested to potentiate a non-classical pathway. We hypothesized that examining PR status in ER-positive proliferating cells could tell which pathway is more dominant in ER-positive breast cancer. Methods: To test the hypothesis, we used a newly developed triplex immunohistochemistry (IHC) that detects three molecules simultaneously under bright-field microscopy. Postmenopausal patients who were treated with neoadjuvant endocrine therapy with aromatase inhibitors from January 2007 to September 2016 at Saitama Cancer Center were included in this study. ER, PR, and Ki67 expressions were assessed in a single slide using the triplex IHC assay with anti-ER antibody (clone SP1), anti-PR antibody (clone 1E2), and anti-Ki67 antibody (clone 30-9). ER, PR and Ki67 expression was assessed in a single cell nucleus of cancer cells (567 to 4871 cells) from multiple areas in each case. An ER-positive proliferating cell was defined as an ER-positive and Ki67-positive cell. PR status in ER-positive proliferating cells was assessed. When PR was expressed in more than 50% of ER-positive proliferating cells in a clinical case, the tumor was categorized as the PR-positive group. Luminal A and luminal B breast cancers were defined based on the pre-treatment Ki67 labeling index with a cut-off of 14 %. Statistical analyses included the Mann-Whitney test, the log-rank test, and the Cox proportional hazard model. Results: Pre-treatment tissues from 55 patients were evaluated. The median age was 62 (range: 54 to 80) years. The patients were grouped into PR-positive and PR-negative groups. The two groups had no differences in age and pre-treatment T and N stages. The median pre-treatment Ki67 labeling index was 5.9 % in the PR-positive group and 9.9 % in the PR-negative group, which showed a statistically significant difference (P = 0.01). Clinical response to neoadjuvant endocrine therapy was compared, and no difference was observed. The median post-treatment Ki67 labeling index was 3.6 % in the PR-positive group and 13.1 % in the PR-negative group with a significant difference (P = 0.035). The survival was compared between the two groups. The PR-positive group showed a significantly more favorable disease-free survival (DFS) than the PR-negative group (P = 0.0079). To adjust for the background differences including Ki67 and PR status, a multivariate analysis was performed and showed that the PR-positive group had a significantly better DFS than the PR-negative group independent of clinical stage, Ki67 labeling index, and PR status (P = 0.042). Breast cancer-specific survival (BCSS) was also better in the PR-positive group than in the PR-negative group after adjusting for clinical stage, Ki67 labeling index, and PR status (P = 0.043). Interestingly, among patients with luminal A tumors, those in the PR-positive group showed a better DFS than those in the PR-negative group (P = 0.022). Conclusion: PR status in ER-positive proliferating cells was an independent prognostic factor in DFS and BCSS and divided patients with luminal A tumors further into two prognostic groups. Citation Format: Takayuki Ueno, Rie Horii, Hiroshi Matsumoto, Makiko Ono, Yurina Maeshima, Hiroaki Nitta. Co-expression of estrogen receptor (ER), progesterone receptor (PR), and Ki67 in a single breast cancer cell indicates a favorable prognosis in ER-positive breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-01-08.

Interaction of dinuclear Co(III) cylinders with higher-order DNA structures

Alternative DNA structures play critical roles in fundamental biological processes linked to human diseases. Thus, targeting and stabilizing these structures by specific ligands could affect the progression of cancer and other diseases. Here, we describe, using methods of molecular biophysics, the interactions of two oxidatively locked [Co2L3]6+ cylinders, rac-2 and meso-1, with diverse alternative DNA structures, such as junctions, G quadruplexes, and bulges. This study was motivated by earlier results demonstrating that both Co(III) cylinders exhibit potent and selective activity against cancer cells, accumulate in the nucleus of cancer cells, and prove to be efficient DNA binders. The results show that the bigger cylinder rac-2 stabilizes all DNA structures, while the smaller cylinder meso-1 stabilizes just the Y-shaped three-way junctions. Collectively, the results of this study suggest that the stabilization of alternative DNA structures by Co(III) cylinders investigated in this work might contribute to the mechanism of their biological activity.

Abstract 6882: Exploring aryl hydrocarbon receptor expression and distribution in the tumor microenvironment, with a focus on immune cells, in various solid cancer types

Abstract Background: The aryl hydrocarbon receptor (AhR) is a transcription factor that performs various biological functions upon ligand activation. While there have been extensive studies and development of AhR-targeting anticancer therapies, including active clinical trials, research on the expression of AhR, a key biomarker, in the TME remain limited. Herein, we evaluated the nuclear and cytosolic AhR expression across five solid cancer types: head and neck squamous cell carcinoma (HNSCC), bladder cancer, colorectal cancer, esophageal cancer, and non-small cell lung cancer (NSCLC). Methods: Multiplexed immunohistochemistry (mIHC) and image cytometry were employed to investigate the AhR expression and distribution in 513 patient samples, of which 292 were from patients with one of five solid cancer types. For quantification of AhR expression levels, FCS files were generated, and the resulting data was analyzed using the R program. Results: AhR expression was predominantly high in cancer cells, followed by T cells and macrophages across all cancer types. All 513 patient samples were categorized into three clusters based on distinct expression and localization patterns of AhR. Cluster 1 exhibited high AhR expression in the cancer cell nucleus, whereas cluster 3 showed the lowest. AhR expression in the stromal macrophage nucleus was the most pronounced in cluster 2. In cluster 1, NSCLC was entirely absent, with esophageal cancer representing the largest proportion. In contrast, cluster 2 was notably different from cluster 1, with a 5% prevalence of NSCLC and a relatively higher proportion of HNSCC and colorectal cancer. The AhR expression in macrophages within cluster 2 was noticeably higher than in cluster 1. Cluster 3, which had the highest NSCLC proportion, generally displayed low AhR expression compared to other clusters, but also exhibited AhR expression in regulatory T cells (Tregs), a pattern which was not observed in other cancer types. Notably, a positive correlation was observed between the nuclear and cytosolic expressions of AhR, suggesting that AhR expression as a biomarker is independent of its subcellular localization. Furthermore, there was no clear correlation between AhR expression levels and cancer stage, grade, and metastatic status. Conclusion: We elucidated the expression profile of AhR within the TME across five cancer types, then classified the patient samples into three clusters based on their distinct AhR expression patterns. By demonstrating different expression patterns of AhR in cancer cells and immune cells, our findings are anticipated to provide a fundamental basis for clinical and immunological research on AhR-targeting therapies. Citation Format: Dong Kwon Kim, Chai Young Lee, Yu Jin Han, So Young Park, Heekyung Han, Kwangmin Na, Mi Hyun Kim, Seung Min Yang, Sujeong Baek, Youngtaek Kim, Joon Yeon Hwang, Seul Lee, Seong-san Kang, Taedong Han, Hyounmie Doh, Jongho Cho, Dajeong Kim, Daewon Cha, Min Hee Hong, Sun Min Lim, Jii Bum Lee, Jae Hwan Kim, Kyoung-Ho Pyo, Byoung Chul Cho. Exploring aryl hydrocarbon receptor expression and distribution in the tumor microenvironment, with a focus on immune cells, in various solid cancer types [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6882.

Abstract 2746: MAGE-A3 co-expression with IDH1-R132H and IL-1β in colon cancer

Abstract Colorectal cancer (CRC) remains a significant cause of cancer death worldwide with an estimated 52,000 deaths in 2023. Over the past few decades, the incidence rate of CRC in individuals younger than 50 has been steadily increasing. Currently, diagnostic biomarkers play an important role in the detection and treatment of CRC. MAGE-A3 has been shown to be expressed in many tumor types, including colon cancer by RNA expression. Due to their high sequence homology, members of the MAGEA family have been difficult to evaluate and screen for their protein expression. However, in a previous study, highly specific antibodies were identified using CytoSections for MAGE-A3 immunohistochemistry. IL-1β is a cytokine that induces inflammatory responses and when localized to the nucleus in colon cancer cells it can promote stemness. IL-1β expression has been shown to be increased in wildtype IDH1 positive glioblastoma. However, the relationship between IL-1β and IDH1 has not been studied in colon cancer. In this study, the difference in the expression of MAGE-A3, IL-1β, and wildtype IDH1 compared to mutant IDH1-R132H in colon cancer tissues was evaluated. The results show that IL-1β, wildtype IDH1, and MAGE-A3 were co-expressed in 27 of the 38 colon cancer tumors. However, IDH1-R132H expression was only seen in 20% of the tumors. This study suggests that MAGE-A3, IL-1β, and IDH1 are candidate biomarkers for immunotherapy due to their high expression in colon cancer tissues. Citation Format: Andy/Xi Han, Rachel Gonzalez, Jina Yom, Zhaoying Guo, Bailey Gilmore, Eden Zewdu, Tianli Qu, Hailey/YiChen Guo, Qi Ren, Xiaomin Hu, Ranran Zhang, Zhaohui Wu, Xuan Liu, Wei Fu. MAGE-A3 co-expression with IDH1-R132H and IL-1β in colon cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2746.

Abstract 3095: A high-throughput phenotypic screen to identify small molecule inhibitors of Werner helicase

Abstract Werner helicase (WRN) is a RecQ DNA helicase involved in genome maintenance and DNA damage repair. It has recently been shown to be essential to cancer cells with high microsatellite instability (MSI-H). In MSI-H cancer cells, WRN depletion was shown to induce DNA damage and disrupt mitoses, resulting in a distinct phenotype of enlarged and fragmented nuclei. Here, we present a high-throughput phenotypic screen to identify compounds that selectively induce enlarged nuclei in MSI-H cancer cells. In HCT116, an MSI-H colorectal cancer cell line, approximately 40% of cells exhibited enlarged nuclei when WRN was depleted using siRNA. In contrast, fewer than 10% of control cells displayed this phenotype. In HT29, a microsatellite stable (MSS) cancer cell line, no such difference in nuclear morphology was observed, suggesting that the phenotype is specific to MSI-H cells. We used high content imaging to screen our in-house diversity library of approximately 175,000 compounds in 384-well format. 4,260 compounds induced enlarged nuclei in HCT116 cells, a 2.4% hit rate. After re-screening hits in HCT116 along with two additional MSI-H cancer cell lines, SW48 and SNU-407, and counter-screening in HT29 cells, 144 hits were confirmed to specifically enlarge nuclei in MSI-H but not MSS cells. Using the ADP-Glo Kinase Assay, two of these compounds were confirmed to inhibit WRN ATPase activity, suggesting WRN inhibition as a potential mechanism for their specific effects in MSI-H cells. This screen will also identify compounds which selectively kill MSI-H cells through mechanisms beyond direct inhibition of WRN, including interaction with WRN complex members or other members of DNA damage repair pathways. Validation studies including the assessment of cell viability and DNA damage in a panel of MSI-H and MSS cell lines will be performed. Our study proposes a phenotypic screening strategy for identifying small molecules with the potential to target WRN and uncover additional novel mechanisms for treating MSI-H cancers. Citation Format: Christine A. Moomau, Yipin Lu, Xiaobin Zhang, Xiang Zhai, Lina Gu, Qing Sheng, Fang Li, Yaoyu Chen. A high-throughput phenotypic screen to identify small molecule inhibitors of Werner helicase [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3095.

Cucurbit[8]uril-based non-covalent heterodimer realized NIR cell imaging through topological transformation from nanowire to nanorod

In recent years, multicolor cascade supramolecular assemblies with controllable topological morphology have become a research hotspot due to their wide application in light-emitting materials, cell imaging and other fields. Herein, several kinds of macrocycles including cucurbiturils, calixarene and cyclodextrins are used as building blocks to construct fluorescent assemblies with anthryl-conjugated phenylpyridine (G), wherein cucurbit[8]uril (CB[8]) and G can form nanowires at a stoichiometric ratio of n:n through host-guest encapsulation to form a non-covalent heterodimer. Significantly, the macrocycle confinement effect drastically enhances the fluorescence emission of G and emission peak generated bathochromic shift from 500 nm to 600 nm. When the supramolecular polymer is further assembled with amphiphilic calix[4]arene (SC4A8), the fluorescence emission of G⊂CB[8] further increases to 1.4 times, accompanied by the morphological transformation from linear structure to nanorod structure. Subsequently, a very small amount of dye Cy5 is added to the assembly solution as an energy receptor, and the negatively charged G⊂CB[8]@SC4A8 system is regarded as an energy donor. The efficient energy transfer process enables near-infrared (NIR) emission at 675 nm with 71% energy transfer efficiency (ΦET) at a donor/receptor ratio of 100:1. Finally, the cascade supramolecular assembly has been successfully applied to targeted imaging in the nucleus of HeLa and A549 cancer cells.

Mechanical comparison of isolated and living breast cancer cell nuclei

Mechanical comparison of isolated and living breast cancer cell nuclei

Intratumoral Biosynthesis of Gold Nanoclusters by Pancreatic Cancer to Overcome Delivery Barriers to Radiosensitization.

Nanoparticle delivery to solid tumors is a prime challenge in nanomedicine. Here, we approach this challenge through the lens of biogeochemistry, the field that studies the flow of chemical elements within ecosystems as manipulated by living cellular organisms and their environments. We leverage biogeochemistry concepts related to gold cycling against pancreatic cancer, considering mammalian organisms as drivers for gold nanoparticle biosynthesis. Sequestration of gold nanoparticles within tumors has been demonstrated as an effective strategy to enhance radiotherapy; however, the desmoplasia of pancreatic cancer impedes nanoparticle delivery. Our strategy overcomes this barrier by applying an atomic-scale agent, ionic gold, for intratumoral gold nanoparticle biosynthesis. Our comprehensive studies showed the cancer-specific synthesis of gold nanoparticles from externally delivered gold ions in vitro and in a murine pancreatic cancer model in vivo; a substantial colocalization of gold nanoparticles (GNPs) with cancer cell nuclei in vitro and in vivo; a strong radiosensitization effect by the intracellularly synthesized GNPs; a uniform distribution of in situ synthesized GNPs throughout the tumor volume; a nearly 40-day total suppression of tumor growth in animal models of pancreatic cancer treated with a combination of gold ions and radiation that was also associated with a significantly higher median survival versus radiation alone (235 vs 102 days, respectively).

ARID1 and BRG1 Expression in Endometrial Cancer.

Endometrial cancer (EC) is the predominant malignancy among gynecologic cancers and ranks fourth among all types of cancer. Recently, researchers have focused on the development of new prognostic biomarkers. Subunits of the SWI/SNF protein complex, like the ARID1 and BRG1, have been associated with the development of endometrial cancer. The present study aimed to evaluate the expression patterns of ARID1A and BRG1 in a collection of endometrioid adenocarcinomas of the uterus using immunohistochemistry. The study comprised a total of thirty-three individuals diagnosed with stage I endometrioid endometrial cancer, treated with radical hysterectomy. The histological material was then examined to assess the cytoplasmic and nuclear expression of the proteins. ARID1A exhibited expression in both the cytoplasm and nucleus of cancer cells, whereas BRG1 was mainly expressed in the nuclei. In addition, ARID1A exhibited a notable decrease in expression in grade 3 histology, with no significant correlation with the depth of myometrial invasion. The reduced expression was highly related to tumor expansion into the endocervix. The findings demonstrated a total absence of ARID1A expression in 27% of endometrioid carcinomas, with a significant reduction in expression in an additional 51% of cancer cells. These findings align with the most recent published data. In contrast, in the current study, BRG1 was rarely down-regulated and was extensively expressed in the majority of endometrioid carcinomas, preventing the possibility of statistical analysis. In summary, ARID1A expression loss can be used as a biomarker to guide post-operative therapy; however, further investigation is needed, especially for early-stage endometrial cancer.

Brevilin A Binds with Neh1 Domain of NRF2 and Inhibits its Translocation into Nucleus in Cancer Cells

Brevilin A Binds with Neh1 Domain of NRF2 and Inhibits its Translocation into Nucleus in Cancer Cells

PiR-1919609 Is an Ideal Potential Target for Reversing Platinum Resistance in Ovarian Cancer.

PIWI-interacting RNAs (piRNAs) are a type of noncoding small RNA that can interact with PIWI-like RNA-mediated gene silencing (PIWIL) proteins to affect biological processes such as transposon silencing through epigenetic effects. Recent studies have found that piRNAs are widely dysregulated in tumors and associated with tumor progression and a poor prognosis. Therefore, this study aimed to investigate the effect of piR-1919609 on the proliferation, apoptosis, and drug resistance of ovarian cancer cells. In this study, we used small RNA sequencing to screen and identify differentially expressed piRNAs in primary ovarian cancer, recurrent ovarian cancer, and normal ovaries. A large-scale verification study was performed to verify the expression of piR-1919609 in different types of ovarian tissue, including ovarian cancer tissue and normal ovaries, by RT-PCR and to analyze its association with the clinical prognosis of ovarian cancer. The expression of PIWILs in ovarian cancer was verified by RT-PCR, Western blotting and immunofluorescence. The effects of piR-1919609 on ovarian cancer cell proliferation, apoptosis and drug resistance were studied through in vitro and in vivo models. (1) piR-1919609 was highly expressed in platinum-resistant ovarian cancer tissues (p < 0.05), and this upregulation was significantly associated with a poor prognosis and a shorter recurrence time in ovarian cancer patients (p < 0.05). (2) PIWIL2 was strongly expressed in ovarian cancer tissues (p < 0.05). It was expressed both in the cytoplasm and nucleus of ovarian cancer cells. (3) Overexpression of piR-1919609 promoted ovarian cancer cell proliferation, inhibited apoptosis, and promoted tumor growth in nude mice. (4) Inhibition of piR-1919609 effectively reversed ovarian cancer drug resistance. In summary, we showed that piR-1919609 is involved in the regulation of drug resistance in ovarian cancer cells and might be an ideal potential target for reversing platinum resistance in ovarian cancer.

Nuclear-Targeting Lipid PtIV Prodrug Amphiphile Cooperates with siRNA for Enhanced Cancer Immunochemotherapy by Amplifying Pt-DNA Adducts and Reducing Phosphatidylserine Exposure.

Patients treated with Pt-based anticancer drugs (PtII) often experience severe side effects and are susceptible to cancer recurrence due to the limited bioavailability of PtII and tumor-induced immunosuppression. The exposure of phosphatidylserine on the cell's outer surface induced by PtII results in profound immunosuppression through the binding of phosphatidylserine to its receptors on immune cells. Here, we report a novel approach for enhanced cancer chemoimmunotherapy, where a novel nuclear-targeting lipid PtIV prodrug amphiphile was used to deliver a small interfering RNA (siXkr8) to simultaneously amplify Pt-DNA adducts and reduce the level of exposure of phosphatidylserine. This drug delivery vehicle is engineered by integrating the PtIV prodrug with self-assembly performance and siXkr8 into a lipid nanoparticle, which shows tumor accumulation, cancer cell nucleus targeting, and activatable in a reduced microenvironment. It is demonstrated that nuclear-targeting lipid PtIV prodrug increases the DNA cross-linking, resulting in increased Pt-DNA adduct formation. The synergistic effects of the PtIV prodrug and siXkr8 contribute to the improvement of the tumor immune microenvironment. Consequently, the increased Pt-DNA adducts and immunogenicity effectively inhibit primary tumor growth and prevent tumor recurrence. These results underscore the potential of utilizing the nuclear-targeting lipid PtIV prodrug amphiphile to enhance Pt-DNA adduct formation and employing siXkr8 to alleviate immunosuppression during chemotherapy.

Nitro Compounds Inhibit Breast Cancer Cell Proliferation, Migration, and Colony Formation: Molecular Docking, Molecular Dynamics Simulations and Pharmacological Properties

AbstractIn this study, the concept of combined in vitro and in silico studies were utilized by using some synthesized nitro bearing compounds. The anticancer activities of the studied compounds were performed by using colony formation analysis, cell cytotoxicity, and migration. Nitro group containing two compounds were analyzed using Hoechst staining to indicate the morphological changes on the nuclei of cancer cells under fluorescence microscopy. Scanning electron microscopy (SEM) analysis was performed with N,N‐dibutyl‐nitro‐substituted compound. Nitro containing anticancer agents were shown the inhibition at 1.5 μM and 2 μM concentrations, and nuclear apoptosis was detected. In addition, cell‐to‐cell interaction on MDA‐MB‐231 cells was broken and observed morphologic changes following the treatment with N,N‐dibutyl‐nitro‐substituted compound at the effective doses. In general, the other nitro compounds showed cell cytotoxicity at 5 μM, 10 μM, and 20 μM. Two hits as anticancer agents were determined as potential interleukin‐1 receptor‐associated kinase 1 (IRAK1) and interleukin‐1 receptor‐associated kinase 4 (IRAK4) inhibitor candidates. Molecular docking and molecular dynamics (MD) simulations studies will provide that the binding patterns with specific residues such as Met265, Tyr284 of the IRAK family members, and these will contribute to further in vitro and in vivo studies for targeted breast cancer therapy.

Progesterone receptor-Grb2 interaction is associated with better outcomes in breast cancer

In addition to mediating nuclear transcription, PR mediates extranuclear functions mainly through the PR polyproline domain (PPD) interaction with the SH3 domain of cytoplasmic signaling molecules. PR-PPD-SH3 interaction inhibits EGF-mediated signaling and decreases lung cancer cell proliferation. Grb2 is an essential adaptor molecule with an SH2 domain flanked by two SH3 domains. In this study, we examined whether PR, through interaction between PR-PPD and Grb2-SH3, can interact with Grb2 in cells and breast cancer tissues. Our previous study shows that interaction between PR-PPD and Grb2 could interfere with cytoplasmic signaling and lead to inhibition of EGF-mediated signaling. GST-pulldown analysis shows that PR-PPD specifically interacts with the SH3 domains of Grb2. Immunofluorescence staining shows colocalization of PR and Grb2 in both the nucleus and cytoplasm in BT-474 breast cancer cells. Using Bimolecular Fluorescence Complementation (BiFC) analysis, we show that PR and Grb2 interact in breast cancer cells through the Grb2-SH3 domain. Proximity Ligation Assay (PLA) analysis of 43 breast cancer specimens shows that PR-Grb2 interaction is associated with low histological stage and negatively correlates with lymph node invasion and metastasis in breast cancer. These results, together with our previous findings, suggest that PR-PPD interaction with Grb2 plays an essential role in PR-mediated growth factor signaling inhibition and could contribute significantly to better prognosis in PR- and Grb2-positive breast cancer. Our finding provides a basis for additional studies to explore a novel therapeutic strategy for cancer treatment.

Programmed cell death 11 modulates but not entirely relies on p53-HDM2 loop to facilitate G2/M transition in colorectal cancer cells

We previously described a nucleolar protein RSL1D1 but distributed throughout the nucleus in HCT116 colorectal cancer (CRC) cells to facilitate G1/S transition by inhibiting p53 signaling. Here, we found another nucleolar protein, programmed cell death 11 (PDCD11), also with an “Extra-nucleolar” localization in CRC cells but to regulate G2/M checkpoint. This protein directly interacts with p53 and HDM2 in the nucleoplasm, thereby recruiting p53 to HDM2 for ubiquitination and degradation. The ensuing downregulation of p53 increases the CDK1 level to help the cells pass G2/M checkpoint. Upon DNA damage stress, PDCD11 gains the power to upregulate CDK1 independently of p53. Beyond these, PDCD11 also upregulates CDC25C in a p53-independent manner to dephosphorylate CDK1 to facilitate G2/M transition. Downregulation of PDCD11 greatly reduced cancer cell growth in vitro and in vivo, additionally sensitized cells to DNA damage signals, highlighting that PDCD11 is a crucial driving factor of CRC and a potential target for cancer treatment.

KMT2A maintains stemness of gastric cancer cells through regulating Wnt/β-catenin signaling-activated transcriptional factor KLF11.

The molecular mechanisms of epigenetic regulation in gastric cancer development are not yet well established. In this study, we demonstrated that KMT2A was highly expressed in gastric cancer and associated with poor outcomes of patients and revealed that KMT2A was significantly associated with stemness and increased nuclear β-catenin in gastric cancer. Mechanistically, KMT2A activated the translocation of β-catenin into the nucleus of gastric cancer cells, and then, β-catenin served as a coactivator of KLF11, which promoted the expression of specific gastric cancer stemness-related molecules, including SOX2 and FOXM1. Together, KMT2A is an important epigenetic regulator of gastric cancer stemness, which provides a novel insight to the potential application of targeting against KMT2A in treating gastric cancer.

Cathepsin V regulates cell cycle progression and histone stability in the nucleus of breast cancer cells.

Introduction: We previously identified that Cathepsin V (CTSV) expression is associated with poor prognosis in ER+ breast cancer, particularly within the Luminal A subtype. Examination of the molecular role of the protease within Luminal A tumours, revealed that CTSV promotes tumour cell invasion and proliferation, in addition to degradation of the luminal transcription factor, GATA3, via the proteasome. Methods: Cell line models expressing CTSV shRNA or transfected to overexpress CTSV were used to examine the impact of CTSV on cell proliferation by MTT assay and flow cytometry. Western blotting analysis was used to identify the impact of CTSV on histone and chaperone protein expression. Cell fractionation and confocal microscopy was used to illustrate the presence of CTSV in the nuclear compartment. Results: In this work we have identified that CTSV has an impact on breast cancer cell proliferation, with CTSV depleted cells exhibiting delayed progression through the G2/M phase of the cell cycle. Further investigation has revealed that CTSV can control nuclear expression levels of histones H3 and H4 via regulating protein expression of their chaperone sNASP. We have discovered that CTSV is localised to the nuclear compartment in breast tumour cells, mediated by a bipartite nuclear localisation signal (NLS) within the CTSV sequence and that nuclear CTSV is required for cell cycle progression and histone stability in breast tumour cells. Discussion: Collectively these findings support the hypothesis that targeting CTSV may have utility as a novel therapeutic target in ER+ breast cancer by impairing cell cycle progression via manipulating histone stabilisation.

Single-Cell Analysis with Silver-Coated Pipette by Combined SERS and SICM.

The study of individual cell processes that occur both on their surface and inside is highly interesting for the development of new medical drugs, cytology and cell technologies. This work presents an original technique for fabricating the silver-coated pipette and its use for the cell analysis by combination with surface-enhanced Raman spectroscopy (SERS) and scanning ion-conducting microscopy (SICM). Unlike the majority of other designs, the pipette opening in our case remains uncovered, which is important for SICM. SERS-active Ag nanoparticles on the pipette surface are formed by vacuum-thermal evaporation followed by annealing. An array of nanoparticles had a diameter on the order of 36 nm and spacing of 12 nm. A two-particle model based on Laplace equations is used to calculate a theoretical enhancement factor (EF). The surface morphology of the samples is investigated by scanning electron microscopy while SICM is used to reveal the surface topography, to evaluate Young's modulus of living cells and to control an injection of the SERS-active pipettes into them. A Raman microscope-spectrometer was used to collect characteristic SERS spectra of cells and cell components. Local Raman spectra were obtained from the cytoplasm and nucleus of the same HEK-293 cancer cell. The EF of the SERS-active pipette was 7 × 105. As a result, we demonstrate utilizing the silver-coated pipette for both the SICM study and the molecular composition analysis of cytoplasm and the nucleus of living cells by SERS. The probe localization in cells is successfully achieved.