Cellular Oncology最新文献

Background: Ovarian cancer (OC) is a lethal gynecologic malignancy with limited therapeutic success due to late diagnosis and therapy resistance. Endoplasmic reticulum (ER) stress and ER-associated degradation (ERAD) are key to tumor adaptation, yet the mechanisms sustaining ER homeostasis in OC remain poorly defined.

Methods: We combined multi-omics analyses, tissue microarrays, and in vitro and in vivo models. Functional assays involved COPB2 knockdown or overexpression in OC cells, xenografts in nude mice, and mechanistic studies including protein interaction and glycoproteomic analyses.

Results: COPB2 was significantly upregulated in OC and associated with poor prognosis. It promoted cell proliferation and survival by alleviating ER stress and suppressing apoptosis. Mechanistically, COPB2 interacted with EDEM3, a key ERAD enzyme, enhancing its ER localization and mannose-trimming function. COPB2 depletion impaired EDEM3 activity, resulting in glycan processing defects and ER stress accumulation. In vivo, COPB2 overexpression accelerated tumor growth.

Conclusions: This study identifies a novel COPB2-EDEM3 axis that maintains ER homeostasis and drives OC progression. Targeting this axis may offer new opportunities for therapeutic intervention and biomarker development.

Background: Immune checkpoint inhibitors (ICIs), such as anti-programmed cell death protein-1 (PD-1) immunotherapy, have emerged as promising treatments for advanced hepatocellular carcinoma (HCC), significantly improving clinical outcomes. However, resistance to ICIs remains a major challenge, and the underlying mechanisms of this resistance are not yet fully understood. This study aimed to investigate the role of S100 calcium-binding protein A9 (S100A9) in mediating resistance to anti-PD-1 therapy.

Approach and results: We conducted RNA sequencing (RNA-seq) on tumor samples from anti-PD-1 responders and non-responders in HCC patients. Differential expression analysis identified S100A9 as a potential driver gene of resistance to anti-PD-1 therapy. Subcutaneous tumor models and an orthotopic HCC model established via hydrodynamic transfection were utilized to evaluate the impact of S100A9 on the efficacy of PD-1 therapy. Our findings revealed that S100A9 promotes resistance to anti-PD-1 therapy in HCC. Mechanistically, S100A9 directly interacted with PARP1 and induced its degradation via the ubiquitin-proteasome pathway. This process increased STAT3 phosphorylation at Tyr705, thereby enhancing PD-L1 transcription. Notably, treatment with the S100A9 inhibitor Tasquinimod significantly improved the efficacy of anti-PD-1 therapy in HCC.

Conclusions: Our study reveals that S100A9 facilitates immune evasion in HCC by enhancing PARP1 ubiquitination, STAT3 phosphorylation, and PD-L1 expression. Furthermore, combining S100A9 inhibitors with anti-PD-1 antibodies markedly enhances the therapeutic efficacy of ICIs in HCC. These findings highlight S100A9 as a potential therapeutic target for overcoming resistance to immunotherapy in HCC.

Purpose: Apo10 and TKTL1 are tumor-associated markers reflecting impaired apoptosis and enhanced glycolysis respectively. This study aimed to evaluate the diagnostic potential of Apo10, TKTL1, and APT (a combination of Apo10 and TKTL1) in screening early-stage cervical cancer.

Methods: A total of 152 patients with cervical cancer and 152 age-matched healthy controls were enrolled at Sun Yat-sen University Cancer Center from November 2020 to August 2023. Clinical data were collected from the Hospital Information System (HIS) and medical records, and blood samples were collected from all participants before treatment using epitope detection in monocytes (EDIM) technology 60 min after their last meal. Descriptive statistics and receiver operating characteristic (ROC) curves were used to compare the diagnostic performance of Apo10, TKTL1, and APT to those of conventional cervical cancer biomarkers (CEA, CA125, and SCC-A).

Results: Most of the enrolled patients with cervical cancer had early-stage disease (70%) and squamous cell histology (84.9%). The Apo10, TKTL1, and APT levels were significantly higher in the cervical cancer group than in the control group (Apo10:139 vs. 132, TKTL1:121 vs. 114, APT: 260 vs. 246). We also found that Apo10, TKTL1, and APT showed superior diagnostic performance (AUC: 0.864, 0.865, 0.905) compared to traditional markers (CEA: 0.690, CA125: 0.594, SCC-A: 0.806). Sensitivity analysis revealed APT maintained high diagnostic value across tumor stages and in both HPV-negative (AUC = 0.967) and TCT-negative (AUC = 0.958) subgroups.

Conclusion: Apo10, TKTL1, and APT outperform conventional biomarkers in detecting cervical cancer and may serve as reliable diagnostic indicators.

Introduction: Colorectal cancer (CRC) is a leading cause of cancer-related mortality worldwide. The use of sequential polychemotherapies has improved the survival of patients with advanced metastatic disease. However, the survival rates achieved are low, and chemotherapy-related side effects are significant. Therefore, new, efficient, and tolerable therapies are urgently needed. In this study, we investigate the efficacy of pharmacological cyclin D-dependent kinase (CDK) 4/6 inhibition and explore the relevance of p16 as predictors of susceptibility to CDK 4/6 therapy.

Materials and methods: CDK 4/6 inhibitors were evaluated in native and FOLFOX- or ribociclib-resistant CRC, hepatocellular carcinoma (HCC), and breast cancer (BC) cell lines using viability, colony formation, and flow cytometry (FC)-based assays. Western blotting was employed to assess the expression of Rb and members of the INK4 family. SiRNA-based knockdown of CDK4/6 was utilized to gain insights into mechanisms of action or resistance. Tissue from 185 CRC patients was examined for the expression of p16 and its relevance for progression-free and overall survival. The prognostic relevance of cyclin-dependent kinase inhibitor 2 A (CDKN2A) mRNA expression data was derived from The Cancer Genome Atlas (TCGA) data.

Results: Ribociclib demonstrates significant antitumoral effects in various CRC, HCC, and BC cell lines, similar to two other approved CDK4/6 inhibitors (palbociclib and abemaciclib). Ribociclib-resistant cell lines (Hep-3B, HCC-1937, and BT-549) exhibited higher p16 expression compared to ribociclib-sensitive cell lines. In ribociclib-sensitive cell lines, CDK4/6 inhibition led to G1 phase arrest, whereas resistant cells did not exhibit such effects. A similar phenotype could be observed upon dual siRNA based CDK4/6 knockdown in ribociclib-sensitive HuH-7 and ribociclib-resistant Hep-3B cell lines. All CRC cell lines tested showed sensitivity to ribociclib, including the FOLFOX-resistant SW620 cell line. Low mRNA expression of CDKN2A (p16) was associated with favorable prognosis in CRC patients. No prognostic significance was found for p16 protein expression in an early-stage CRC cohort (n = 185).

Conclusion: Ribociclib demonstrates significant antitumoral effects across a large panel of cancer cell lines and chemoresistant models, especially in CRC. Resistance towards ribociclib is associated with high p16 expression, which is a negative prognostic marker for patients with CRC. Our findings underscore p16 as a promising biomarker for predicting ribociclib responsiveness and emphasize the need for further mechanistic studies and combination therapy approaches to overcome resistance in p16^high patients.

Purpose: Cancer-associated fibroblasts (CAFs), a crucial component of tumor microenvironment, play a critical role in tumorigenesis, progression, and conferring resistance to radiotherapy and chemotherapy. This study aimed to investigate the association between CAFs, CAF- related genes, and radioresistance in hepatocellular carcinoma (HCC).

Methods: CAFs were isolated from HCC tissues and subsequently utilized for co-culturing with HCC cells using CAFs-conditioned medium. An orthotopic HCC mouse model was established by co-implanting CAFs and HCC cells. Through integrative analysis of three RNA-sequencing datasets (TCGA-LIHC tumor vs. normal tissues, Huh7 radioresistant vs. parent cells, and CAF vs. control group), CAF-associated prognostic genes were identified using comprehensive bioinformatics approaches. Experimental validation was performed by real-time quantitative PCR, western blot, immunohistochemistry, cell viability assays, and colony formation assays.

Results: Our findings demonstrated that CAFs significantly enhance radioresistance in HCC. Based on 13 CAF-related prognostic genes, TCGA-LIHC patients were stratified into two distinct clusters via consensus clustering, exhibiting significant differences in overall survival, immune cell infiltration, and therapeutic response. A prognostic nomogram incorporating three hub genes and clinical characteristics was developed. Notably, SOX4 was upregulated in tumor tissues, radioresistant cells, and CAF-exposed HCC cells, correlating with poor prognosis. SOX4 knockdown suppressed HCC proliferation and reversed CAF-induced radioresistance. Additionally, a competitive endogenous RNA (ceRNA) network of LINC00665/miR-122-5p/SOX4 was constructed.

Conclusion: CAFs serve as crucial mediators of radioresistance in HCC, and CAF-related genes provide valuable prognostic and therapeutic insights. SOX4 emerges as a promising therapeutic target to improve radiotherapy efficacy in HCC.

Clinical trial number: Not applicable.

Background: Advanced prostate cancer (PCa) displays significant genetic heterogeneity and therapy resistance, yet the role of sensory perception pathways in its progression remains unclear.

Methods: We performed an integrative multi-omics analysis of sensory perception-linked mRNAs and lncRNAs from TCGA and scRNA-seq data. Unsupervised consensus clustering defined three molecular subtypes (CS1-CS3). Key biomarkers were validated in patient tissues and serum. Immune and stromal infiltration were quantified using TIDE and ESTIMATE. Single-cell trajectories characterized TSC22D3-positive T cells, and NicheNet mapped ligand-receptor interactions.

Results: Three subtypes emerged, with CS1 showing the poorest prognosis, marked chemotherapy resistance, and pronounced stromal-immune crosstalk. CS1 tumors exhibited elevated B- and T-cell infiltration and increased oxidative phosphorylation in TSC22D3-positive T cells. NicheNet analysis identified the TNF-CCL20 axis as a central mediator of immunosuppressive signaling and chemoresistance in CS1.

Conclusions: This study establishes sensory perception-associated molecular subtypes in PCa and links CS1 chemoresistance to immune microenvironment reprogramming via TNF-CCL20 signaling. These findings offer mechanistic insights into PCa progression and suggest actionable targets to overcome therapeutic resistance.

Understanding genetic dependencies in cancer is key to identifying novel actionable drug targets to advance precision medicine. Whole-genome CRISPR-knockout library screening methods have facilitated this goal. Pooled libraries of single guide RNAs (sgRNAs) targeting over 90% of the annotated protein coding genome are used to induce gene knockouts in pre-clinical cancer models. Novel genes of interest are identified by evaluating sgRNA dropout or enrichment following selection pressure application. This method is particularly beneficial for researching cancers where effective treatment strategies are limited. One example of a commonly chemoresistant cancer, particularly at relapse, is the low survival malignancy epithelial ovarian cancer (EOC), made up of multiple histotypes with distinct molecular profiles. CRISPR-knockout library screens in pre-clinical EOC models have demonstrated the ability to predict biomarkers of treatment response, identify targets synergistic with standard-of-care chemotherapy, and determine novel actionable targets which are synthetic lethal with cancer-associated mutations. Robust experimental design of CRISPR-knockout library screens, including the selection of strong pre-clinical cell line models, allows for meaningful conclusions to be made. We discuss essential design criteria for the use of CRISPR-knockout library screens to discover genetic dependencies in cancer and draw attention to discoveries with translational potential for EOC.

Purpose: Pancreatic ductal adenocarcinoma (PDA) remains one of the most lethal malignancies with limited early diagnostic and therapeutic options. Although receptor for activated C kinase 1 (RACK1) is an evolutionarily conserved scaffold protein, its functional role and mechanistic involvement in PDA pathogenesis remain elusive.

Methods: Using multimodal approaches including: (1) genetically engineered mouse models of pancreatitis and carcinogenesis, (2) patient-derived PDA tissues with matched normal specimens, (3) primary acinar cell 3D cultures, and (4) orthogonal gain/loss-of-function assays in PDA cell lines, we systematically investigated RACK1's spatiotemporal expression patterns and functional impacts. Mechanistic dissection was performed through gene expression profiling and pathway enrichment analyses with functional validation.

Results: RACK1 exhibited progressive silencing across pancreatic lesion progression: acinar cells (normal) > ADM > pancreatic intraepithelial neoplasia (PanIN) > PDA. This acinar-specific protein was undetectable in ductal/islet lineages and was further suppressed under inflammatory challenge. Functionally, RACK1 depletion accelerated ADM initiation and enhanced PDA cell motility and metastatic dissemination in vivo, whereas its overexpression exerted tumor-suppressive effects. Mechanistically, caerulein/TGF-α stimulation and Kras^G12D activation converged to inhibit RACK1 while activating MAP2K3-SRC-RELA(p65) signaling nodes, establishing a pro-inflammatory feedforward loop.

Conclusions: RACK1 serves as a gatekeeper restraining inflammation-driven ADM transformation, with its downregulation constituting an early molecular event in PDA pathogenesis. The RACK1-MAP2K3 axis orchestrates malignant transition through simultaneous NF-κB activation (inflammatory priming) and MAPK hyperactivation (proliferative drive). Our findings nominate RACK1 as both a stratification biomarker for high-risk pancreatic lesions and a druggable node for intercepting preneoplastic progression.

Background: Clear cell renal cell carcinoma (ccRCC) is the most common malignant tumor of the urinary system and has the highest mortality rate. In addition to surgical tumor reduction, systemic drug therapy is the most important treatment method for metastatic renal cancer. In recent years, immunotherapeutic drugs represented by PD-1 antibodies have been used in the treatment of metastatic ccRCC and achieved good therapeutic effects. However, due to the occurrence of immune escape, only about 50-60% of patients with advanced renal cancer can significantly benefit from immunotherapy. The mechanism of immune escape is extremely complex and has not been clarified. We intend to delve into the driving mechanisms of immune evasion in ccRCC and explore potential targets for intervention.

Methods: In this study, we analyzed the expression of OTUD1 and related pathways in ccRCC through TCGA, GEO dataset, and cBioPortal web tool. At the same time, a mouse model of allogeneic transplanted clear cell renal cell carcinoma was constructed, and the effect of OTUD1 on anti-PD1 antibody therapy was discussed. Experiments such as co-IP, flow cytometry, and RNA-seq analysis were used to investigate the mechanism by which OTUD1 regulates immunity through STAT3.

Results: This study reveals that OTUD1 suppresses PD-L1 expression and enhances antitumor immunity in clear cell renal cell carcinoma (ccRCC) by deubiquitinating and stabilizing STAT3, thereby inhibiting its nuclear translocation and transcriptional activity. As a key regulator of the JAK-STAT pathway, OTUD1 disrupts PD-1/PD-L1-mediated immune evasion, offering a potential therapeutic strategy to improve immunotherapy responses in ccRCC. These findings highlight the OTUD1-STAT3-PD-L1 axis as a novel mechanism for overcoming immune checkpoint resistance.

Conclusion: Overall, we demonstrate that OTUD1 interacts with STAT3 and deubiquitinates, inhibits its nuclear translocation and activity, and ultimately inhibits immune evasion of ccRCC by downregulating PD-L1.

Background: Gastric cancer (GC) is one of the most common malignant tumor worldwide. Metastasis is leading cases of cancer-related death of GC. It has been found that N⁷-methylguanosine (m7G) modifications play an important role in cancer. However, the role of m7G modifications within mRNA and its "writer" METTL1 and WDR4 in tumors, particularly GC, has not been revealed.

Methods: RT-qPCR, WB and IHC were used to detect the expression of METTL1 and WDR4 in GC cells and tissues. Function-based experiments were performed using METTL1-WDR4 knockdown and overexpression cell lines in vitro and in vivo, including CCK8, colony formation, transwell and nude mice models. Mechanistically, RNA-seq, MeRIP-seq, MeRIP-qPCR, western blot, dot blot, co-IP, ChIP and IHC stainings were performed.

Results: METTL1 and WDR4 were upregulated in GC patients. High expression of METTL1 and WDR4 were associated with poor prognosis. Silencing METTL1-WDR4 inhibited GC cell migration and proliferation in vitro and vivo. Mechanistically, METTL1-WDR4 can enhance the mRNA stability of PIK3C2B and AKT by promoting their m7G levels, which leading the overexpression of p-AKT. Interestingly, we also found that on the one hand, the transcription factor YY1 can promote the mRNA transcription expression of METTL1 and WDR4 at the same time, and on the other hand, METTL1-WDR4 can promote YY1 expression by increasing the level of m7G. This regulation presents positive feedback. Above all, METTL1 and WDR4 ultimately up-regulate the level of m7G and promote the malignant progression of GC.

Conclusions: These findings suggest that METTL1-WDR4 might serve as a potential diagnostic and prognostic biomarker and a therapeutic target for GC treatment by regulating m7G level.