Increased Expression of Mitochondrial UQCRC1 in Pancreatic Cancer Impairs Antitumor Immunity of Natural Killer Cells via Elevating Extracellular ATP

Metabolic plasticity in pancreatic cancer: The mitochondrial connection

BACKGROUND

Cellular metabolism plays a pivotal role in the development and progression of pancreatic ductal adenocarcinoma (PDAC), with dysregulated metabolic pathways contributing to tumorigenesis and therapeutic resistance. Distinct metabolic heterogeneity in pancreatic cancer significantly impacts patient prognosis, as variations in metabolic profiles influence tumor behavior and treatment responses.

SCOPE OF THE REVIEW

This review explores the intricate interplay between mitochondrial dynamics, mitophagy, and cellular metabolism in PDAC. We discuss the significance of mitophagy dysregulation in PDAC pathogenesis, emphasizing its influence on treatment responses and prognosis. Furthermore, we analyze the impact of mitochondrial dynamics alterations, including fission and fusion processes, on PDAC progression and tumorigenesis.

MAJOR CONCLUSION

Targeting mitochondrial metabolism holds promise for advancing PDAC therapeutics. Ongoing clinical trials underscore the therapeutic potential of modulating key regulators of mitochondrial dynamics and mitophagy. Despite inherent challenges, these approaches offer diverse strategies to enhance treatment efficacy and improve patient outcomes.

Integrative analysis disclosing UQCRC1 as a potential prognostic and immunological biomarker of lung adenocarcinoma

Lung cancer is one of the most malignant cancers in the world. Approximately 40 % of lung cancer cases are lung adenocarcinoma (LUAD). Exploring new biomarkers was an urgent need for treatments of LUAD. Here, we aimed to perform a pan-cancer analysis of ubiquinol-cytochrome c reductase core protein 1 (UQCRC1) and verify it in LUAD. Compared to normal samples, we observed that UQCRC1 was significantly enhanced in cervical squamous cell carcinoma and endocervical adenocarcinoma (CESC), LUAD, liver hepatocellular carcinoma (LIHC), and several other cancers. In terms of overall survival, UQCRC1 was positively associated with poor prognosis of LUAD and skin cutaneous melanoma (SKCM). Almost more than 8 % deeply deleted frequency of UQCRC1 was showed in lymphoid neoplasm diffuse large B-cell lymphoma (DLBC). In LUAD, SKCM, and a few cancers, UQCRC1 was negatively correlated with the infiltration of B cells and cancer-associated fibroblasts. As regards further mechanism analysis, we found that UQCRC1 modulated cancer progression via mitochondrial related metabolism and oxidative phosphorylation. Taking advantage of the Kras-driven spontaneous LUAD mice model, online single-cell data, and clinical tissues, we particularly confirmed that UQCRC1 was highly expressed in LUAD and acted as a prognostic marker for LUAD. These findings implied that UQCRC1 played an important role in cancers, especially in LUAD.

RBM47 promotes cell proliferation and immune evasion by upregulating PDIA6: a novel mechanism of pancreatic cancer progression

BACKGROUND

Pancreatic cancer (PC) is a lethal malignancy characterized by poor prognosis and high mortality. We found the highly expressed RNA-binding motif protein 47 (RBM47) in PC progression. The RBM47 expression was negatively correlated with natural killer (NK) cell infiltrate in PC. Moreover, RBM47 was predicted to bind to the 3'-UTR region of Protein Disulfide Isomerase Family A Member 6 (PDIA6), an oncogene of the development of PC. Therefore, we supposed that RBM47 might affect PC progression by regulating PDIA6.

METHODS

Bioinformatics analysis was performed to screen the candidate gene affecting PC progression using public databases. Loss- and gain-of-function effects of RBM47 on cell proliferation, tumor growth, and immune evasion were determined by CCK-8, EdU incorporation, colony formation assays, the xenogeneic tumor model, and co-culture system of PC and NK-92 cells. RBM47-RNA immunoprecipitation (RIP) followed by PCR and dual luciferase reporter assay were used to detect whether RBM47 could interact with the PDIA6 mRNA and how RBM47 would regulate the transcriptional activity of PDIA6, respectively. Simultaneous overexpression of PDIA6 in RBM47 knockdown PC cells was conducted to clarify whether PDIA6 would mediated effects of RBM47. Given the important role of cellular metabolism in cells proliferation and immune evasion, PC cells with RBM47 knockdown were subjected to metabolomics analysis to further investigate how RBM47 regulate PC progression.

RESULTS

RBM47 overexpression drove PC progression by promoting cell proliferation and xenografted tumor growth. Consistently, our results showed that RBM47 overexpression weakened sensitivity of PC cells to cytotoxic NK cells. However, RBM47 knockdown exhibited the opposite effects on proliferation and immune evasion of PC cells. RBM47 was able to bind to the 3'-UTR region of PDIA6, maintained PDIA6 mRNA stability, and increased the PDIA6 expression in PC cells. Rescue experiments supported that PDIA6 overexpression reversed the suppressing effects of RBM47 knockdown on cell proliferation and immune evasion. RBM47 knockdown significantly changed metabolites of PC cells.

CONCLUSIONS

In summary, our findings demonstrate that RBM47 contributes to PC progression, which might be mediated by the upregulated PDIA6 expression and the altered cellular metabolites in PC cells, offering a potential therapeutic target for PC treatment.

Unveiling the immunosuppressive landscape of pancreatic ductal adenocarcinoma: implications for innovative immunotherapy strategies

Pancreatic cancer, particularly pancreatic ductal adenocarcinoma (PDAC), stands as the fourth leading cause of cancer-related deaths in the United States, marked by challenging treatment and dismal prognoses. As immunotherapy emerges as a promising avenue for mitigating PDAC's malignant progression, a comprehensive understanding of the tumor's immunosuppressive characteristics becomes imperative. This paper systematically delves into the intricate immunosuppressive network within PDAC, spotlighting the significant crosstalk between immunosuppressive cells and factors in the hypoxic acidic pancreatic tumor microenvironment. By elucidating these mechanisms, we aim to provide insights into potential immunotherapy strategies and treatment targets, laying the groundwork for future studies on PDAC immunosuppression. Recognizing the profound impact of immunosuppression on PDAC invasion and metastasis, this discussion aims to catalyze the development of more effective and targeted immunotherapies for PDAC patients.

Splicing transcriptome-wide association study to identify splicing events for pancreatic cancer risk

A large proportion of the heritability of pancreatic cancer risk remains elusive, and the contribution of specific mRNA splicing events to pancreatic cancer susceptibility has not been systematically evaluated. In this study, we performed a large splicing transcriptome-wide association study (spTWAS) using three modeling strategies (Enet, LASSO and MCP) to develop alternative splicing genetic prediction models for identifying novel susceptibility loci and splicing introns for pancreatic cancer risk by assessing 8275 pancreatic cancer cases and 6723 controls of European ancestry. Data from 305 subjects of whom the majority are of European descent in the Genotype-Tissue Expression Project (GTEx) were used and both cis-acting and promoter-enhancer interaction regions were considered to build these models. We identified nine splicing events of seven genes (ABO, UQCRC1, STARD3, ETAA1, CELA3B, LGR4 and SFT2D1) that showed an association of genetically predicted expression with pancreatic cancer risk at a false discovery rate ≤0.05. Of these genes, UQCRC1 and LGR4 have not yet been reported to be associated with pancreatic cancer risk. Fine-mapping analyses supported likely causal associations corresponding to six splicing events of three genes (P4HTM, ABO and PGAP3). Our study identified novel genes and splicing events associated with pancreatic cancer risk, which can improve our understanding of the etiology of this deadly malignancy.