TSPAN18 facilitates bone metastasis of prostate cancer by protecting STIM1 from TRIM32-mediated ubiquitination

STIM1, ORAI1, and KDM2B in circulating tumor cells (CTCs) isolated from prostate cancer patients

Introduction: Previous publications have shown that STIM1, ORAI1, and KDM2B, are implicated in Ca2+ signaling and are highly expressed in various cancer subtypes including prostate cancer. They play multiple roles in cancer cell migration, invasion, and metastasis. In the current study we investigated the expression of the above biomarkers in circulating tumor cells from patients with metastatic prostate cancer. Methods: Thirty-two patients were enrolled in this study and CTCs' isolation was performed with Ficoll density gradient. Two different triple immunofluorescence stainings were conducted with the following combination of antibodies: CK/KDM2B/CD45 and CK/STIM1/ORAI1. Slides were analyzed using VyCAP microscopy technology. Results: CTC-positive patients were detected in 41% for (CK/KDM2B/CD45) staining and in 56% for (CK/STIM1/ORAI1) staining. The (CK+/KDM2B+/CD45-) and the (CK+/STIM1+/ORAI1+) were the most frequent phenotypes as they were detected in 85% and 94% of the CTC-positive patients, respectively. Furthermore, the expression of ORAI1 and STIM1 in patients' PBMCs was very low exhibiting them as interesting specific biomarkers for CTC detection. The (CK+/STIM1+/ORAI1+) phenotype was correlated to bone metastasis (p = 0.034), while the (CK+/STIM1+/ORAI1-) to disease relapse (p = 0.049). Discussion: STIM1, ORAI1, and KDM2B were overexpressed in CTCs from patients with metastatic prostate cancer. STIM1 and ORAI1 expression was related to disease recurrence and bone metastasis. Further investigation of these biomarkers in a larger cohort of patients will clarify their clinical significance for prostate cancer patients.

Glycolysis related lncRNA SNHG3 / miR-139-5p / PKM2 axis promotes castration-resistant prostate cancer (CRPC) development and enzalutamide resistance

Although androgen deprivation therapy (ADT) by the anti-androgen drug enzalutamide (Enz) may improve the survival level of patients with castration-resistant prostate cancer (CRPC), most patients may eventually fail due to the acquired resistance. The reprogramming of glucose metabolism is one type of the paramount hallmarks of cancers. PKM2 (Pyruvate kinase isozyme typeM2) is a speed-limiting enzyme in the glycolytic mechanism, and has high expression in a variety of cancers. Emerging evidence has unveiled that microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) have impact on tumor development and therapeutic efficacy by regulating PKM2 expression. Herein, we found that lncRNA SNHG3, a highly expressed lncRNA in CRPC via bioinformatics analysis, promoted the invasive ability and the Enz resistance of the PCa cells. KEGG pathway enrichment analysis indicated that glucose metabolic process was tightly correlated with lncRNA SNHG3 level, suggesting lncRNA SNHG3 may affect glucose metabolism. Indeed, glucose uptake and lactate content determinations confirmed that lncRNA SNHG3 promoted the process of glycolysis. Mechanistic dissection demonstrated that lncRNA SNHG3 facilitated the advance of CRPC by adjusting the expression of PKM2. Further explorations unraveled the role of lncRNA SNHG3 as a 'sponge' of miR-139-5p and released its binding with PKM2 mRNA, leading to PKM2 up-regulation. Together, Our studies suggest that lncRNA SNHG3 / miR-139-5p / PKM2 pathway promotes the development of CRPC via regulating glycolysis process and provides valuable insight into a novel therapeutic approach for the disordered disease.

MT1G, an emerging ferroptosis-related gene: A novel prognostic biomarker and indicator of immunotherapy sensitivity in prostate cancer

BACKGROUND

Prostate cancer is a leading cause of cancer-related deaths in men worldwide. Despite advances in treatment strategies, there is still a need for novel therapeutic targets and approaches. Ferroptosis has emerged as a critical process in the development and progression of several cancers, including prostate cancer (PCA). In this study, we investigate the role of MT1G, a gene implicated in immune responses and ferroptosis, in the pathogenesis of PCA. Our objective is to elucidate its prognostic significance and its impact on the tumor microenvironment, while exploring its potential in enhancing the sensitivity to immune checkpoint inhibitor (ICI) therapy.

METHODS

We utilized a combination of in silico analysis and experimental techniques to investigate the role of MT1G in PCA. First, we analyzed large-scale genomic datasets to assess the expression pattern and prognostic significance of MT1G in PCA patients. Subsequently, we performed functional assays to explore the impact of MT1G in PCA and its potential involvement in modulating immune responses. In addition, we conducted in vivo experiments to evaluate the effect of MT1G on tumor growth and response to ICI therapy.

RESULTS

Our analysis revealed that MT1G expression is significantly downregulated in PCA tissues compared to normal prostate tissues and is associated with poor prognosis. Furthermore, MT1G overexpression inhibited the growth of PCA cells in vitro and in vivo. Importantly, we found that MT1G regulates the tumor microenvironment by modulating immune cell infiltration and inhibiting immunosuppressive factors. Furthermore, our study reveals a significant correlation between MT1G expression levels and the response to immune checkpoint inhibitor (ICI) therapy in prostate cancer (PCA) patients, as MT1G upregulation leads to an increase in PDL-1 expression. These findings underscore the potential of MT1G as a promising predictive biomarker for ICI therapy response in PCA patients.

CONCLUSION

Our study elucidates the pivotal role played by MT1G in the pathogenesis of prostate cancer (PCA) and its profound implications for prognosis. Moreover, it raises the intriguing possibility that MT1G could pave the way for novel therapeutic approaches in PCA treatment. This potential arises from its ability to orchestrate immune infiltration within the tumor microenvironment, consequently enhancing sensitivity to immune checkpoint inhibitor (ICI) therapy. Therefore, our findings hold substantial promise for advancing our comprehension of PCA and exploring innovative therapeutic strategies.

The key cellular senescence related molecule RRM2 regulates prostate cancer progression and resistance to docetaxel treatment

BACKGROUND

Prostate cancer is a leading cause of cancer-related deaths among men worldwide. Docetaxel chemotherapy has proven effective in improving overall survival in patients with castration-resistant prostate cancer (CRPC), but drug resistance remains a considerable clinical challenge.

METHODS

We explored the role of Ribonucleotide reductase subunit M2 (RRM2), a gene associated with senescence, in the sensitivity of prostate cancer to docetaxel. We evaluated the RRM2 expression, docetaxel resistance, and ANXA1 expression in prostate cancer cell lines and tumour xenografts models. In addition, We assessed the impact of RRM2 knockdown, ANXA1 over-expression, and PI3K/AKT pathway inhibition on the sensitivity of prostate cancer cells to docetaxel. Furthermore, we assessed the sensitivity of prostate cancer cells to the combination treatment of COH29 and docetaxel.

RESULTS

Our results demonstrated a positive association between RRM2 expression and docetaxel resistance in prostate cancer cell lines and tumor xenograft models. Knockdown of RRM2 increased the sensitivity of prostate cancer cells to docetaxel, suggesting its role in mediating resistance. Furthermore, we observed that RRM2 stabilizes the expression of ANXA1, which in turn activates the PI3K/AKT pathway and contributes to docetaxel resistance. Importantly, we found that the combination treatment of COH29 and docetaxel resulted in a synergistic effect, further augmenting the sensitivity of prostate cancer cells to docetaxel.

CONCLUSION

Our findings suggest that RRM2 regulates docetaxel resistance in prostate cancer by stabilizing ANXA1-mediated activation of the PI3K/AKT pathway. Targeting RRM2 or ANXA1 may offer a promising therapeutic strategy to overcome docetaxel resistance in prostate cancer.