Expression Levels Of c-Myc Research Articles

The potential role of Circular RNA New biomarkers for the prognosis of hepatocellular carcinoma

Abstract Introduction/Objective Hepatocellular carcinoma (HCC) is the most commonly diagnosed cancer with related deaths worldwide. The non-coding RNAs as the functions of circRNAs in tumor progression have attracted great attention to the clinicopathological characteristics of HCC. Methods/Case Report The present study was conducted to investigate and evaluate the expression level of hsa_circ_2124, and hsa_circ_4018 downstream target gene pathways related to clinico-pathological parameters of HCC. Cell proliferation was examined by West-1 assay and protein expression levels by using western blotting analysis. Results (if a Case Study enter NA) The hsa_circ_2124 expression level was up-regulated in HepG2 and Hep3B cells, respectively compared to normal liver cells. Furthermore, hsa_circ_4018 was down-regulated in two HCC cell lines compared to the normal cell line (LO2 cells), demonstrating the heterogeneity characteristics of the circRNA expressions in different HCC cell lines. Our data showed a significant inhibition of hsa_circ_4018 in HCC cell lines which in turn inhibited cell proliferation and migration. Besides, there is an inhibition in cell proliferation after hsa_circ_2124 knockdown in the tested cell lines. In addition, our data reported that the Knockdown of hsa_circ_2124 reduced the expression of ERK, c-Myc, and β-catenin expression in Hep-G2 cells. Furthermore, hsa_circ_4018 showed significant inhibition in β-catenin and c-Myc expression levels in Hep3B cells compared to the control. The knockdown of hsa_circ_2124 induced G1-phase arrest in HepG2 cells compared to control, suggesting the role of hsa_circ_2124 in the inhibition of HCC progression. Conclusion All in all, our data revealed that hsa_circ_2124 or hsa_circ_4018 plays a role in the regulation of MAPK and Wnt/β-catenin signaling pathways, which might be potential therapeutic biomarkers for HCC.

Application of XBP1s Decoy Oligodeoxynucleotide Attenuates Cancerous Phenotype in Huh-7 Hepatocellular Carcinoma Cells.

The spliced form of X-box binding protein 1 (XBP1s) is a key transcription factor in the unfolded protein response (UPR), an adaptive mechanism for cell survival. Many studies demonstrated the induced expression of XBP1s in various cancers, including hepatocellular carcinoma (HCC). Such upregulated expression is linked to an enhancement of cell proliferation, migration, and improvement of the survival rate. In this study, we aimed to assess the therapeutic potential of targeting XBP1s, by specific decoy oligodeoxynucleotide (ODN) and evaluated the cancerous phenotypes in Huh-7 cells. In this experimental study, we transfected Huh-7 cells with XBP1s decoy oligonucleotide (ODN). Subsequently, we assess some cellular features, including viability, migration capacity, proliferation potential, and apoptosis. Therefore, various techniques included wound healing test, BrdU, and annexin/PI assays. Additionally, the colony formation capacity was evaluated. The mRNA expression levels of BAX, BCL-2, c-MYC, CCND1, MMP-9, CDH1, and CD133 were quantified by the reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Transfection of Huh-7 cells by XBP1s decoy ODN led to significant down-regulation of c-Myc, CCND1, MMP-9, BCL-2 and CD133 and up-regulation of CDH1 and BAX transcriptional expressions in comparison with the vehicle group. Our results also demonstrated that transfection of XBP1s-decoy reduced HCC cell viability, proliferation, migration capacity as well as colonization ability in comparison with the vehicle group. These findings proposed the potential application of XBP1s-decoy ODN to reduce cancerous phenotypes such as cell proliferation, cell migration and apoptosis induction in the Huh-7 cell line. More experiments on other cell lines and primary cells could validate our results.

Xanthine negatively regulates c-MYC through the PI3K/AKT signaling pathway and inhibits the proliferation, invasion, and migration of breast cancer cells.

Breast cancer is a prevalent and aggressive malignancy associated with elevated mortality rates worldwide. Dysregulation of the c-MYC oncogene and aberrant activation of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway are common features in breast cancer progression, rendering them attractive therapeutic targets. Here, we assessed the effects of the plant derivative, xanthine, on breast cancer cells and explored the molecular mechanisms underlying its activity. Breast cancer cell lines were treated with xanthine, followed by assessment of c-MYC expression levels. Cell proliferation, invasion, and migration were analyzed to assess the effects of xanthine treatment on breast cancer cell behavior. Xanthine treatment induced a decrease in c-MYC expression, resulting in significant inhibition of breast cancer cell proliferation, invasion, and migration. Mechanistic investigations revealed that these effects were mediated by suppression of the PI3K/AKT signaling pathway. Xanthine shows great potential for breast cancer treatment by targeting c-MYC via the PI3K/AKT signaling pathway. Our findings indicate that development of xanthine as a novel treatment option for breast cancer, which acts by influencing key oncogenic pathways involved in tumor progression, may be warranted.

Bioactive stem cell-laden 3D nanofibrous scaffolds for tissue engineering

This study presents biomimetic nanoscaffolds composed of electrospun polycaprolactone-collagen (PCL-Coll) nanofibers, loaded with bioactive Arnebia euchroma (AE) extract and stem cells, to develop cell-based tissue engineering constructs. The incorporation of AE extract, known for its antioxidant and anti-inflammatory properties, into the PCL-Coll nanofibers resulted in nanoscaffolds denoted as PCL-Coll/AE0, PCL-Coll/AE5, PCL-Coll/AE10, and PCL-Coll/AE15, corresponding to AE extract concentrations of 0.0, 5.0, 10.0, and 15.0 wt%, respectively. The PCL-Coll/AE nanoscaffolds exhibited high porosity values of 62.81 ± 4.78 %, 59.9 ± 2.10 %, 52.44 ± 2.66 %, and 46.32 ± 1.35 %, respectively, thereby providing an optimal 3D environment for cell attachment and proliferation. Analysis of the AE extract revealed the presence of abundant shikonin, a key bioactive compound, as indicated by its characteristic absorption bands at 490, 520, and 560 nm. FE-SEM data confirmed the homogeneous immobilization of AE compounds within the 3D nanofiber scaffolds, with fibers averaging 316 ± 137 nm in diameter, falling within the range of natural collagen fibers. To evaluate the structural integrity of the fully stem cell-laden scaffolds, we assessed cell growth, cell attachment within the PCL-Coll/AE nanoscaffolds, the cytoprotective effects of AE extract, and the expression levels of stemness-related genes, including Nanog, Rex1, Sox2, Oct4, Klf4, and C-Myc. Real-time PCR assays indicated that key indicators of stemness were upregulated, with average increases from 120 ± 15 % in PCL-Coll/AE0 to 250 ± 30 % in PCL-Coll/AE15 over a two-week period. These upregulations promote cell proliferation and facilitate cell cycle progression. Data indicate that increasing the concentration of bioactive AE extract within the scaffolds enhanced cell adhesion on the scaffold surface and improved cell viability after 7 days of culture, with viability rising from 109 ± 6.15 % in PCL-Coll/AE0 to 145.5 ± 10.11 % in PCL-Coll/AE15. Cytoprotective assays against oxidative stress induced by H₂O₂ revealed relative cell viability for PCL-Coll/AE0, PCL-Coll/AE5, PCL-Coll/AE10, and PCL-Coll/AE15 as 42.78 ± 5.85 %, 49.29 ± 6.79 %, 64.98 ± 3.32 %, and 78.68 ± 3.09 %, respectively. These results correlate with the antioxidant potency of AE extract compounds, particularly shikonin and its derivatives. Therefore, the cell-laden biomimetic PCL-Coll/AE15 scaffolds, which demonstrate sustained stemness features and a continuous local release of bioactive AE compounds, represent a promising candidate for tissue engineering applications.

Changes in the molecular nodes of the Notch and NRF2 pathways in cervical cancer tissues from the precursor stages to invasive carcinoma.

Cancer is a multifactorial disease characterized by the loss of control in the expression of genes known as cancer driver genes. Cancer driver genes trigger uncontrolled cell replication, which leads to the development of malignant tumors. A cluster of signal transduction pathways that contain cancer driver genes involved in cellular processes, such as cell proliferation, differentiation, apoptosis and dysregulated organ growth, are associated with cancer initiation and progression. In the present study, three signal transduction pathways involved in cervical cancer (CC) development were analyzed: The Hippo pathway (FAT atypical cadherin, yes-associated protein 1, SMAD4 and TEA domain family member 2), the Notch pathway [cellular-MYC, cAMP response element-binding binding protein (CREBBP), E1A-associated cellular p300 transcriptional co-activator protein and F-Box and WD repeat domain containing 7] and the nuclear factor erythroid 2-related factor 2 (NRF2) pathway [NRF2, kelch-like ECH-associated protein 1 (KEAP1), AKT and PIK3-catalytic subunit α]. Tumor samples from patients diagnosed with various stages of CC, including cervical intraepithelial neoplasia (CIN) 1, CIN 2, CIN 3, in situ CC and invasive CC, were analyzed. The mRNA expression levels were analyzed using reverse transcription-quantitative PCR assays, whereas protein expression levels were assessed through immunohistochemical tissue microarrays. High mRNA expression levels of c-MYC and AKT and low expression levels of NRF2 and KEAP1 were associated with a decreased survival time of patients with CC. Additionally, increased expression levels of c-MYC were detected in the invasive CC stage. At the protein level, increased NRF2 expression levels were observed in all five stages of CC samples compared with those in the cancer-free control samples. AKT1 was found to be dysregulated in the CIN 1 and CIN 2 stages, PI3K in the in situ and invasive stages, and CREBBP in the CIN 3 and in situ stages. In summary, the present study demonstrated significant changes in proteins of the Notch and NRF2 pathways in CC. NRF2 was overexpressed in all cervical cancer stages (cervical intraepithelial neoplasia, in situ CC and invasive CC). The present study makes an important contribution to the possible biomarker proteins to be analyzed for the presence of premalignant and malignant lesions in the cervix.

C-Myc Inhibition Induces an Additive Effect with Cyclophosphamide in Acute Lymphoblastic Leukemia

Background: Cellular-myelocytomatosis (c-Myc), an oncoprotein and a transcription factor, is involved in several essential cellular processes. The c-Myc expression level is highly regulated in normal cells. It has been proved that c-Myc expression is deregulated in malignant cells due to rearrangements and mutations. The overexpression of this molecule is also reported to be present in acute lymphoblastic leukemia (ALL) as well, which is correlated with an unfavorable response to treatment, poor prognosis, and decreased overall survival. The upregulation of c-Myc results in increased proliferation, cell growth, and survival of ALL cells. Hence, making it an ideal target for leukemia treatment. This study evaluates the effect of c-Myc silencing combined with cyclophosphamide treatment, an FDA-approved chemotherapeutic. Methods: Peripheral blood and bone marrow samples (mononuclear cells) were derived from eleven ALL patients. To silence c-Myc, small interfering-RNA (siRNA)-lipofectamine was used. The efficacy of gene silencing was assessed by the qRT-PCR test. Next, the effect of c-Myc silencing combined with cyclophosphamide treatment in ALL primary cells was evaluated using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) test. Results: ALL cells were successfully transfected with c-Myc-siRNA. Also, treating cells with cyclophosphamide exerted a slight fall in the c-Myc mRNA level. The MTT test revealed that following the inhibition of c-Myc by siRNA, the viability of primary ALL cells decreased in response to cyclophosphamide treatment. Also, it was discovered that silencing c-Myc with siRNA combined with cyclophosphamide treatment significantly inhibits the growth of primary ALL cells compared to cyclophosphamide monotherapy. Conclusion: c-Myc possesses high potential in the treatment of several cancers. Our findings add ALL to this category as well. Silencing c-Myc sensitizes ALL cells to cyclophosphamide treatment and can help with the better treatment of the afflicted individuals.

Retraction Note: Transcription elongation factor A-like 7, regulated by miR-758-3p inhibits the progression of melanoma through decreasing the expression levels of c-Myc and AKT1

Retraction Note: Transcription elongation factor A-like 7, regulated by miR-758-3p inhibits the progression of melanoma through decreasing the expression levels of c-Myc and AKT1

Shikonin Suppresses Cell Tumorigenesis in Gastric Cancer Associated with the Inhibition of c-Myc and Yap-1.

The study aimed to study the potential roles and mechanisms of shikonin in gastric cancer by network pharmacology and biological experiments. The key genes and targets of shikonin in gastric cancer were predicted by network pharmacology and molecular docking study. The effect of shikonin on the proliferation, migration, and invasion of gastric cancer cells was detected by the CCK8 method, and wound healing and transwell assays. The expression levels of c-Myc and Yap-1 were detected via western blotting in gastric cancer cells after shikonin intervention. The results of network pharmacology revealed the key target genes of shikonin on gastric cancer cells to be c-Myc, Yap-1, AKT1, etc. GO and KEGG analysis showed regulation of cell migration, proliferation, adhesion, and other biological processes, including the PI3K-Akt signaling pathway, HIF-1 signaling pathway, necroptosis, and other cancer pathways. Molecular docking showed shikonin to be most closely combined with protooncogenes c-Myc and Yap-1. In vitro experiments showed that the proliferation rate, migration, and invasion ability of the gastric cancer cell group decreased significantly after shikonin intervention for 24h. The expression levels of c-Myc and Yap-1 in gastric cancer cells were found to be significantly decreased after shikonin intervention. This study showed protooncogenes c-Myc and Yap-1 to be the core target genes of shikonin on gastric cancer cells. Shikonin may suppress gastric cancer cells by inhibiting the protooncogenes c-Myc and Yap-1. This suggests that shikonin may be a good candidate for the treatment of gastric cancer.

Screening and identification of miRNAs negatively regulating FAM83A/Wnt/β-catenin signaling pathway in non-small cell lung cancer

The prevalence of non-small cell lung cancer (NSCLC) accounts for 85% of all lung cancers, with the Wnt/β-catenin signaling pathway exhibiting robust activation in this particular subtype. The expression of FAM83A (family with sequence similarity 83, member A) has been found to be significantly upregulated in lung cancer, leading to the stabilization of β-catenin and activation of the Wnt signaling pathway. In this study, we conducted a screening of down-regulated miRNAs in lung cancer with FAM83A as the target. Ultimately, we identified miR-1 as a negative regulator of FAM83A and confirmed that FAM83A is a direct target gene of miR-1 through dual luciferase reporter assays. The overexpression of miR-1 significantly attenuated the expression level of FAM83A and suppressed the Wnt signaling pathway, leading to a reduction in the expression levels of downstream target genes AXIN2, CyclinD1, and C-MYC. Additionally, it decreased the nuclear translocation of β-catenin. In addition, overexpression of miR-1 accelerated the degradation of β-catenin by inhibiting FAM83A, promoted the assembly of β-catenin degradation complex, and inhibited the proliferation, migration and invasion of NSCLC cells. In summary, miR-1 may be a potential candidate miRNA for the treatment of NSCLC.

Identification of a Novel Protein Phosphatase 2A Activator, PPA24, as a Potential Therapeutic for FOLFOX-Resistant Colorectal Cancer.

A series of compounds were designed utilizing molecular modeling and fragment-based design based upon the known protein phosphatase 2A (PP2A) activators, NSC49L and iHAP1, and evaluated for their ability to inhibit the viability of colorectal cancer (CRC) and folinic acid, 5-fluorouracil, and oxaliplatin (FOLFOX)-resistant CRC cells. PPA24 (19a) was identified as the most cytotoxic compound with IC50 values in the range of 2.36-6.75 μM in CRC and FOLFOX-resistant CRC cell lines. It stimulated PP2A activity to a greater extent, displayed lower binding energies through molecular docking, and showed higher binding affinity through surface plasmon resonance for PP2A catalytic subunit α than the known PP2A activators. PPA24 dose-dependently induced apoptosis and oxidative stress, decreased the level of c-Myc expression, and synergistically potentiated cytotoxicity when combined with gemcitabine and cisplatin. Furthermore, a PPA24-encapsulated nanoformulation significantly inhibited the growth of CRC xenografts without systemic toxicities. Together, these results signify the potential of PPA24 as a novel PP2A activator and a prospective therapeutic for CRC and FOLFOX-resistant CRC.

A positive feedback loop between PFKP and c-Myc drives head and neck squamous cell carcinoma progression

BackgroundThe aberrant expression of phosphofructokinase-platelet (PFKP) plays a crucial role in the development of various human cancers by modifying diverse biological functions. However, the precise molecular mechanisms underlying the role of PFKP in head and neck squamous cell carcinoma (HNSCC) are not fully elucidated.MethodsWe assessed the expression levels of PFKP and c-Myc in tumor and adjacent normal tissues from 120 HNSCC patients. A series of in vitro and in vivo experiments were performed to explore the impact of the feedback loop between PFKP and c-Myc on HNSCC progression. Additionally, we explored the therapeutic effects of targeting PFKP and c-Myc in HNSCC using Patient-Derived Organoids (PDO), Cell Line-Derived Xenografts, and Patients-Derived Xenografts.ResultsOur findings indicated that PFKP is frequently upregulated in HNSCC tissues and cell lines, correlating with poor prognosis. Our in vitro and in vivo experiments demonstrate that elevated PFKP facilitates cell proliferation, angiogenesis, and metastasis in HNSCC. Mechanistically, PFKP increases the ERK-mediated stability of c-Myc, thereby driving progression of HNSCC. Moreover, c-Myc stimulates PFKP expression at the transcriptional level, thus forming a positive feedback loop between PFKP and c-Myc. Additionally, our multiple models demonstrate that co-targeting PFKP and c-Myc triggers synergistic anti-tumor effects in HNSCC.ConclusionOur study demonstrates the critical role of the PFKP/c-Myc positive feedback loop in driving HNSCC progression and suggests that simultaneously targeting PFKP and c-Myc may be a novel and effective therapeutic strategy for HNSCC.

CTLA-4 silencing could promote anti-tumor effects in hepatocellular.

Preclinical and clinical research showed that immune checkpoint blockade provides beneficial effects for many patients with liver cancer. This study aimed to assess the effect of CTLA-4-specific siRNA on the proliferation, cell cycle, migration, and apoptosis of HePG2 cells. Transfection of siRNA was performed by electroporation. The viability of cells was determined through MTT assay. Flow cytometry was performed to investigate the cell cycle and apoptosis rate, and the wound-healing assay was used to determine HepG2 cells migration. The expression levels of CTLA-4, c-Myc, Ki-67, BCL-2, BAX, caspase-9 (CAS9), and MMP-2,9,13 were measured by qRT-PCR. Transfection of specific CTLA-4-siRNA significantly inhibited the expression of the CTLA-4 gene. Also, our results revealed that CTLA-4 silencing diminished the proliferation and migration as well as induced the apoptosis of HePG2 cells. CTLA-4-siRNA transfection induced the cell cycle arrest in G2 phase. Moreover, CTLA-4-siRNA transfection reduced the expression levels of c-Myc, Ki-67, BCL-2, MMP-2,9,13, and elevated the expression levels of BAX and caspase-9. Our results suggest that silencing CTLA-4 through specific siRNA may be a promising strategy for future therapeutic interventions for treating liver cancer.

Arenobufagin inhibits lung metastasis of colorectal cancer by targeting c-MYC/Nrf2 axis

Colorectal cancer (CRC) is one of the commonest cancers worldwide. Metastasis is the most common cause of death in patients with CRC. Arenobufagin is an active component of bufadienolides, extracted from toad skin and parotid venom. Arenobufagin reportedly inhibits epithelial-to-mesenchymal transition (EMT) and metastasis in various cancers. However, the mechanism through which arenobufagin inhibits CRC metastasis remains unclear. This study aimed to elucidate the molecular mechanisms by which arenobufagin inhibits CRC metastasis. Wound-healing and transwell assays were used to assess the migration and invasion of CRC cells. The expression of nuclear factor erythroid-2-related factor 2 (Nrf2) in the CRC tissues was assessed using immunohistochemistry. The protein expression levels of c-MYC and Nrf2 were detected by immunoblotting. A mouse model of lung metastasis was used to study the effects of arenobufagin on CRC lung metastasis in vivo. Arenobufagin observably inhibited the migration and invasion of CRC cells by downregulating c-MYC and inactivating the Nrf2 signaling pathway. Pretreatment with the Nrf2 inhibitor brusatol markedly enhanced arenobufagin-mediated inhibition of migration and invasion, whereas pretreatment with the Nrf2 agonist tert‑butylhydroquinone significantly attenuated arenobufagin-mediated inhibition of migration and invasion of CRC cells. Furthermore, Nrf2 knockdown with short hairpin RNA enhanced the arenobufagin-induced inhibition of the migration and invasion of CRC cells. Importantly, c-MYC acts as an upstream modulator of Nrf2 in CRC cells. c-MYC knockdown markedly enhanced arenobufagin-mediated inhibition of the Nrf2 signaling pathway, cell migration, and invasion. Arenobufagin inhibited CRC lung metastasis in vivo. Together, these findings provide evidence that interruption of the c-MYC/Nrf2 signaling pathway is crucial for arenobufagin-inhibited cell metastasis in CRC. Collectively, our findings show that arenobufagin could be used as a potential anticancer agent against CRC metastasis. The arenobufagin-targeted c-MYC/Nrf2 signaling pathway may be a novel chemotherapeutic strategy for treating CRC.

Abstract 5957: Development of a selective, oral ATP-competitive CDK9 inhibitor, BLX-3030, for treatment of pancreatic cancer

Abstract Introduction Transcription regulators, such as cyclin-dependent kinase 9 (CDK9), have been implicated in the super-enhancer driven transcriptional control of oncogenes in multiple cancers including pancreatic cancer. CDK9 has been shown to be employed by cancer cells for the constant production of short-lived oncoproteins such as c-Myc to maintain their survival. Due to its critical role in regulating transcription in cancer cells, CDK9 has emerged as a potential therapeutic target. Here, we report the antitumor activity of a selective, oral ATP-competitive CDK9 inhibitor, BLX-3030, in preclinical models for pancreatic cancer. Experimental Procedures Fragment-based MolecuLern driven AI workflow methods were used to design a series of ATP-competitive CDK9 specific kinase inhibitors. BLX-3030 was selected as one of the most potent leads with an IC50 of 1.1 nM in a cell-free CDK9 kinase assay. A Sulforhodamine B (SRB) assay was used to evaluate the cell growth inhibitory activity of BLX-3030 in a panel of 10 pancreatic ductal adenocarcinoma (PDAC) and 2 pancreatic neuroendocrine tumor (pNET) cell lines. Western blotting was used to determine the effects of BLX-3030 treatment on c-Myc expression in cancer cells. The combination effects between BLX-3030 and standard of care regimen, gemcitabine (GEM) and nab-paclitaxel (NP), was assessed using the SRB assay. Finally, the in vivo antitumor activity of BLX-3030 alone or in combination with GEM and NP was evaluated in a mouse cell line xenograft model for pancreatic cancer. Results BLX-3030 exhibited potent cell growth inhibitory activity in the panel of pancreatic cancer cell lines with IC50 values ranging from 133.5 nM to 508.1 nM. The potency of BLX-3030 in the cell lines appears to correlate with the expression level of c-Myc in the cell lines. BLX-3030 showed similar activities in PDAC and pNET cell lines with mean IC50 values of 244.5 nM and 194.6 nM, respectively. However, treatment with BLX-3030 for 48 hours did not seem to significantly reduce c-Myc expression in PSN-1 PDAC cells. When combined with GEM and NP, BLX-3030 demonstrated mostly additive effects in PSN-1 cells. Preliminary data from the in vivo study show that BLX-3030 improves the antitumor activity of GEM and NP. Conclusion In summary, BLX-3030 potently inhibited the growth of both PDAC and pNET cells in vitro. The growth inhibitory activity of BLX-3030 in PDAC cell lines correlates with their c-Myc expression levels. BLX-3030 showed an additive effect when combined with standard of care drugs (GEM and NP) in PDAC cell lines. Overall, the novel CDK9 inhibitor, BLX-3030, demonstrated potent activity in pancreatic cancer cell line models and presents a promising preclinical lead for pancreatic cancer. (This work was supported in part by Biolexis Therapeutics and the Seena Magowitz Foundation). Citation Format: Yesenia Barrera-Millan, Zhaoliang Li, Hariprasad Vankayalapati, David J. Bearss, Daniel D. Von Hoff, Haiyong Han. Development of a selective, oral ATP-competitive CDK9 inhibitor, BLX-3030, for treatment of pancreatic 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 5957.

Abstract 6926: Tracing clonal evolution and immune evasion in glioblastoma progression

Abstract Glioblastoma continues to be a daunting obstacle in oncology research, with its early-stage progression being particularly enigmatic. In a recent published work, we traced the clonal dynamics of glioblastoma evolution by the simultaneous transfer of PDGFB and genetic barcodes into mouse brains. We observed a continuous clonal loss during the acquisition of a malignant phenotype, underlined by the modulation of the levels of c-Myc expression and their functional targets. In this study, we delve deeper into the evolution of glioblastoma by transplanting multiclonal, early-stage glioma cells into multiple immunodeficient NOD-SCID mice. This experimental design allowed us to track the clonal dynamics over serial transplants, revealing how early-stage glioma clones acquire immune-evasive features capable of initiating tertiary tumors in immune-competent hosts. Through barcode sequencing and single-cell RNA sequencing of early-stage gliomas, coupled with bulk RNA sequencing of secondary and tertiary gliomas, we dissected the clonal and transcriptomic landscape of these tumors. We observed that, of the various clones composing primary tumors, just a few of them are predominating in subsequent passages. Furthermore, the clonal composition of secondary tumors derived from the same primary glioma showed partial overlap, indicating a partial predetermination in the development of immune-evasive behavior. Our intra- and inter-clonal transcriptomic analysis across various stages of tumor progression is shedding light on how new functional traits can emerge in gliomas. Further analysis of our data will determine whether it is the result of the expansion of clones already possessing these traits, or if they stem from functional adaptations within the clones themselves. Our insights further reinforce the concept of clonal competition, highlighting the significant influence of immune-system interactions in driving these competitive dynamics. Citation Format: Davide Ceresa, Sebastian A. Garcia Mena, Francesca Piaggio, Appolloni Irene, Daniela Marubbi, Paolo Malatesta. Tracing clonal evolution and immune evasion in glioblastoma progression [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 6926.

WNT5A regulatesthe proliferation, apoptosis and stemness of human stem Leydig cells via the β-catenin signaling pathway.

Stem Leydig cells (SLCs) are essential for maintaining normal spermatogenesis as the significant component of testis microenvironment and gonadal aging. Although progress has been achieved in the regulation of male germ cells in mammals and humans, it remains unknown about the genes and signaling pathways of human SLCs. Here we have demonstrated, for the first time, that WNT5A (Wnt family member 5a) mediates the proliferation, apoptosis, and stemness of human SLCs, namely NGFR+ Leydig cells. We revealed that NGFR+ Leydig cells expressed NGFR, PDGFRA, NES, NR2F2, and THY1, hallmarks for SLCs. RNA-sequencing showed that WNT5A was expressed at a higher level in human SLCs than non-SLCs, while immunohistochemistry and Western blots further illustrated that WNT5A was predominantly expressed in human SLCs. Notably, CCK-8, EdU and Western blots displayed that WNT5A enhanced the proliferation and DNA synthesis and retained stemness of human SLCs, whereas flow cytometry and TUNEL analyses demonstrated that WNT5A inhibited the apoptosis of these cells. WNT5A knockdown caused an increase in LC lineage differentiation of human SLCs and reversed the effect of WNT5A overexpression on fate decisions of human SLCs. In addition, WNT5A silencing resulted in the decreases in nuclear translocation of β-catenin and expression levels of c-Myc, CD44, and Cyclin D1. Collectively, these results implicate that WNT5A regulates theproliferation, apoptosis and stemness of human SLCs through the activation of the β-catenin signaling pathway. This study thus provides a novel molecular mechanism underlying the fate determinations of human SLCs, and it offers a new insight into the niche regulation of human testis.

Resveratrol Inhibits T-acute Lymphoblastic Leukemia in Mice by Regulating Notch1 Signaling Pathway

To observe the effect of resveratrol (Res) on T-acute lymphoblastic leukemia (T-ALL) mice, and further explore its mechanism on Notch1 signaling pathway. Twenty-five 6-8 weeks old female C57BL/6 mice were randomly divided into control group, T-ALL group and Res group. Res group was further divided into low-Res, middle-Res and high-Res group. The percentage of leukemia cells in peripheral blood and spleen cell suspension were detected by flow cytometry and Wright-Giemsa staining, pathological morphology of spleen and bone marrow tissues were observed by HE staining, the expression levels of Notch1, Hes-1, c-Myc, miR-19b and PTEN mRNA in spleen tissue were detected by RT-qPCR, and the protein levels of Notch1, Hes-1, c-Myc, p-PTEN and PTEN were detected by Western blot. Compared with control group, the leukemia cells in peripheral blood of mice in T-ALL group were markedly increased, accompanied by diffuse infiltration of leukemia cells in spleen and bone marrow tissues, the mRNA levels of Notch1, Hes-1, c-Myc, miR-19b and the protein levels of Notch1, Hes-1, c-Myc were increased (P <0.01), while the expression of PTEN mRNA and protein were significantly decreased in the spleen tissue of T-ALL mice (P <0.01). The above indicators in the H-Res group were reversed compared with T-ALL group after administration of resveratrol. Resveratrol may play a role in anti T-ALL by inhibiting Notch1 signaling pathway in mice.

ZNF692 promotes cell proliferation, invasion and migration of human prostate cancer cells by targeting the EMT signaling pathway

BackgroundProstate cancer poses a considerable threat to human health. At present, the mechanism of tumor progression remains unclear. ZNF692 is overexpressed in many tumors, and the high expression of ZNF692 is correlated with tumor aggressiveness and tumor phenotype of prostate cancer, suggesting that ZNF692 may play an important role in tumor biology of prostate cancer. This paper aims to elucidate the relationship between them.MethodsThe expression level of ZNF692 was verified in normal prostate cells (RWPE-1) and prostate cancer cells (LNCaP, PC3, DU145). PC3 cells were selected to construct the ZNF692 knockout prostate cancer cell line. The changes of cell proliferation, apoptosis, invasion and metastasis were detected by CCK8, Edu staining, Transwell assay and scratch assay. The expression levels of related proteins were detected by Western blot.ResultsAt the cellular level, ZNF692 was overexpressed to varying degrees in prostate cancer cell lines, with the highest expression in PC3 cell lines. CCK8 and Edu results showed that the proliferation of prostate cancer PC3 cells that knocked down ZNF692 was slowed. Transwell assay and scratch assay showed reduced invasion and migration of prostate cancer PC3 cells that knocked out ZNF692. Flow cytometry showed that the apoptosis rate of prostate cancer PC3 cells after ZNF692 knockout was increased. In addition, after ZNF692 silencing, the expression level of epithelial phenotype E-cadherin increased in PC3 cells, while the expression level of interstitial phenotype N-cadherin, Vimentin, c-Myc, and CyclinA1 decreased. The state of prostate cancer PC3 cells that overexpressed ZNF692 was reversed from the state after ZNF692 was knocked down.ConclusionZNF692 can be used as a new prognostic marker and a potential biologic therapeutic target for PCa. By inhibiting the expression of c-myc and cyclinA1, the EMT signaling pathway is regulated to provide evidence for its potential molecular mechanism.

Discovery of Palbociclib as a potent c-Myc G4 stabilizer for lung cancer treatment using molecular docking, molecular dynamics simulation, and in vitro activity evaluation.

Despite significant progress in lung cancer treatment, this disease remains a prevalent and serious global malignancy, leading to high rates of illness and death. Urgent research is needed to discover new or alternative therapies that can improve clinical outcomes for lung cancer patients. In our study, we successfully demonstrated the effectiveness of Palbociclib, a CDK4/6 inhibitor, in suppressing the growth of lung cancer cells. The IC50 values obtained were 11.00μM and 11.74μM for H1299 and A549 cells, respectively. Furthermore, our findings indicate that Palbociclib may possess strong c-Myc G4 stabilizing properties by significantly reducing both protein and mRNA expression levels of c-Myc. Additionally, Palbociclib induces apoptosis and causes cell cycle arrest at the G2/M phase in two cells. Through circular dichroism (CD), molecular docking, and molecular dynamics (MD) simulation, we have provided evidence that Palbociclib enhances the structural stability of c-Myc G4 while exhibiting a high binding affinity to its ligand's binding site on c-Myc G4. These results suggest that Palbociclib holds promise as a novel c-Myc G4 stabilizer for treating cancers associated with abnormal c-Myc activity; further optimization and development are warranted.

Correlations between C-myc expression, BMI-1 expression, and vaginal microecology with HPV-DNA load in patients with different cervical lesions.

To investigate the correlations between the expressions of proto-oncogenes C-myc and B-cell-specific Moloney leukemia virus integration site-1 (BMI-1), vaginal microecology, and human papillomavirus-DNA (HPV-DNA) load in patients with different cervical lesions. A total of 51 patients with cervix squamous cell carcinoma (CSCC), 72 patients with cervical intraepithelial neoplasia (CIN) and 50 patients with normal cervix (NC) who were diagnosed or admitted between Jan. 1st 2020 and Dec. 31st 2022 at the Suzhou Hospital of Integrated Traditional Chinese and Western Medicine were selected and divided into three groups, i.e., the CSCC group, the CIN group and the NC group, for a retrospective analysis. Hybrid capture 2 (hc2) was used to detect the HPV-DNA load in each group. Immunohistochemistry was performed to detect C-myc and BMI-1 expressions in each group. The indicators of vaginal microecology in patients were compared among groups to analyze the correlations between C-myc, BMI-1 expressions, vaginal microecology and HPV-DNA load. The HPV-DNA load and expression levels of positive C-myc and BMI-1 in the CSCC group were all higher than those of the CIN and NC groups (P<0.05). The detection rate of lactobacillus in the CSCC group was lower than that of the CIN and NC groups. The percentages of leukocyte esterase (LE) positivity and pH ≥4.6 were higher in the CSCC group than those in the CIN and NC groups (P<0.05). The difference in the detection rate of spores among the three groups was not significant (P>0.05). Both C-myc and BMI-1 scores were positively correlated with HPV-DNA load in the 173 samples. The proto-oncogenes C-myc and BMI-1 were highly expressed in the cervical tissues of CIN and CSCC patients, whose vaginal microecology was also altered. Both may play an important role in the progression of cervical lesions.