PD-1 inhibitor plus anlotinib for metastatic castration-resistant prostate cancer: a real-world study.

Management and treatment of terminal metastatic castration-resistant prostate cancer (mCRPC) remains heavily debated. We sought to investigate the efficacy of programmed cell death 1 (PD-1) inhibitor plus anlotinib as a potential solution for terminal mCRPC and further evaluate the association of genomic characteristics with efficacy outcomes. We conducted a retrospective real-world study of 25 mCRPC patients who received PD-1 inhibitor plus anlotinib after the progression to standard treatments. The clinical information was extracted from the electronic medical records and 22 patients had targeted circulating tumor DNA (ctDNA) next-generation sequencing. Statistical analysis showed that 6 (24.0%) patients experienced prostate-specific antigen (PSA) response and 11 (44.0%) patients experienced PSA reduction. The relationship between ctDNA findings and outcomes was also analyzed. DNA-damage repair (DDR) pathways and homologous recombination repair (HRR) pathway defects indicated a comparatively longer PSA-progression-free survival (PSA-PFS; 2.5 months vs 1.2 months, P = 0.027; 3.3 months vs 1.2 months, P = 0.017; respectively). This study introduces the PD-1 inhibitor plus anlotinib as a late-line therapeutic strategy for terminal mCRPC. PD-1 inhibitor plus anlotinib may be a new treatment choice for terminal mCRPC patients with DDR or HRR pathway defects and requires further investigation.

HDAC4 promotes the growth and metastasis of gastric cancer via autophagic degradation of MEKK3.

BACKGROUND: Histone deacetylases (HDACs) have been shown to be involved in tumorigenesis, but their precise role and molecular mechanisms in gastric cancer (GC) have not yet been fully elucidated. METHODS: Bioinformatics screening analysis, qRT-PCR, and immunohistochemistry (IHC) were used to identify the expression of HDAC4 in GC. In vitro and in vivo functional assays illustrated the biological function of HDAC4. RNA-seq, GSEA pathway analysis, and western blot revealed that HDAC4 activated p38 MAPK signalling. Immunofluorescence, western blot, and IHC verified the effect of HDAC4 on autophagy. ChIP and dual-luciferase reporter assays demonstrated that the transcriptional regulation mechanism of HDAC4 and ATG4B. RESULTS: HDAC4 is upregulated in GC and correlates with poor prognosis. In vitro and in vivo assays showed that HDAC4 contributes to the malignant phenotype of GC cells. HDAC4 inhibited the MEF2A-driven transcription of ATG4B and prevented MEKK3 from p62-dependent autophagic degradation, thus activating p38 MAPK signalling. Reciprocally, the downstream transcription factor USF1 enhanced HDAC4 expression by regulating HDAC4 promoter activity, forming a positive feedback loop and continuously stimulating HDAC4 expression and p38 MAPK signalling activation. CONCLUSION: HDAC4 plays an oncogenic role in GC, and HDAC4-based targeted therapy would represent a novel strategy for GC treatment.

Diagnostic and prognostic value of the peripheral natural killer cell levels in gastric cancer.

Peripheral blood lymphocyte subsets have been reported to be useful as prognostic and/or diagnostic markers for patients with cancer. However, the clinical value of peripheral blood lymphocyte subsets in gastric cancer (GC) has remained elusive. In the present study, peripheral CD3+, CD4+ and CD8+ T lymphocytes, B cells (CD19+), regulatory T cells (Tregs; CD4+CD25+CD127-) and natural killer (NK) cells (CD3-CDl6+CD56+) were detected by flow cytometry in 122 patients with GC, 80 healthy donors (HDs) and 80 patients with gastric ulcer (GU). NK cells (CD56+) were detected by immunohistochemical (IHC) analysis in 20 GC and three GU tissue samples. A receiver-operating characteristic (ROC) curve was used to determine the threshold of the peripheral NK cell level and survival analysis was performed to assess its prognostic value in patients with GC. The results indicated that the peripheral NK cell proportion in patients with GC (18.77%) was significantly higher than that in the HD (12.19%) and GU (12.74%) groups. IHC analysis suggested that the NK level in GC tumor samples was correlated with that in paired serum samples. ROC curve analysis indicated that the peripheral NK cell level (15.16%) was able to effectively identify patients with GC, a diagnostic sensitivity of 75.41% and a specificity of 77.45% were determined. Multivariate logistic regression analysis revealed that the peripheral NK cell level was independently associated with the T stage and survival analysis demonstrated that high levels of peripheral NK cells were associated with poor prognosis of patients with GC. In conclusion, the peripheral NK cell level may be a diagnostic and prognostic marker for patients with GC.

BDH2 triggers ROS-induced cell death and autophagy by promoting Nrf2 ubiquitination in gastric cancer.

BACKGROUND: 3-Hydroxy butyrate dehydrogenase 2 (BDH2) is a short-chain dehydrogenase/reductase family member that plays a key role in the development and pathogenesis of human cancers. However, the role of BDH2 in gastric cancer (GC) remains largely unclear. Our study aimed to ascertain the regulatory mechanisms of BDH2 in GC, which could be used to develop new therapeutic strategies. METHODS: Western blotting, immunohistochemistry, and RT-PCR were used to investigate the expression of BDH2 in GC specimens and cell lines. Its correlation with the clinicopathological characteristics and prognosis of GC patients was analysed. Functional assays, such as CCK-8 and TUNEL assays, transmission electron microscopy, and an in vivo tumour growth assay, were performed to examine the proliferation, apoptosis, and autophagy of GC cells. Related molecular mechanisms were clarified by luciferase reporter, coimmunoprecipitation, and ubiquitination assays. RESULTS: BDH2 was markedly downregulated in GC tissues and cells, and the low expression of BDH2 was associated with poor survival of GC patients. Functionally, BDH2 overexpression significantly induced apoptosis and autophagy in vitro and in vivo. Mechanistically, BDH2 promoted Keap1 interaction with Nrf2 to increase the ubiquitination level of Nrf2. Ubiquitination/degradation of Nrf2 inhibited the activity of ARE to increase accumulation of reactive oxygen species (ROS), thereby inhibiting the phosphorylation levels of AktSer473 and mTORSer2448. CONCLUSIONS: Our study indicates that BDH2 is an important tumour suppressor in GC. BDH2 regulates intracellular ROS levels to mediate the PI3K/Akt/mTOR pathway through Keap1/Nrf2/ARE signalling, thereby inhibiting the growth of GC.

SNHG16/miR-605-3p/TRAF6/NF-κB feedback loop regulates hepatocellular carcinoma metastasis.

The mechanism by which miR-605-3p regulates hepatocellular carcinoma (HCC) metastasis has not been clarified. In this study, we found that miR-605-3p was down-regulated in HCC and that low miR-605-3p expression was associated with tumour thrombus and tumour satellites. HCC patients with low miR-605-3p expression showed shorter overall survival and disease-free survival after surgery. Overexpression of miR-605-3p inhibited epithelial-mesenchymal transition and metastasis of HCC through NF-κB signalling by directly inhibiting expression of TRAF6, while silencing of miR-605-3p had the opposite effect. We also found that SNHG16 directly bound to miR-605-3p as a competing endogenous RNA. Mechanistically, high expression of SNHG16 promoted binding to miR-605-3p and inhibited its activity, which led to up-regulation of TRAF6 and sustained activation of the NF-κB pathway, which in turn promoted epithelial-mesenchymal transition and metastasis of HCC. TRAF6 increased SNHG16 promoter activity by activating NF-κB, thereby promoting the transcriptional expression of SNHG16 and forming a positive feedback loop that aggravated HCC malignancy. Our findings reveal a mechanism for the sustained activation of the SNHG16/miR-605-3p/TRAF6/NF-κB feedback loop in HCC and provide a potential target for a new HCC treatment strategy.

Rafoxanide promotes apoptosis and autophagy of gastric cancer cells by suppressing PI3K /Akt/mTOR pathway.

Rafoxanide is commonly used as anti-helminthic medicine in veterinary medicine, a main compound of salicylanilide. Previous studies have reported that rafoxanide, as an inhibitor of BRAF V600E mutant protein, inhibits the growth of colorectal cancer, multiple myeloma, and skin cancer. However, its therapeutic effect on gastric cancer (GC) and the potential mechanism has not been investigated. Here, we have found that rafoxanide inhibited the proliferation of GC cells in vitro, arrested the cell cycle in the G0/G1 phase, and promoted apoptosis and autophagy in GC cells. Treatment with specific autophagy inhibitor 3-methyladenine drastically inhibited the apoptotic cell death effect by suppressing the switch from autophagy to apoptosis. Mechanistically, we found that rafoxanide inhibited the growth of GC cells in vitro by inhibiting the activity of the PI3K/Akt/mTOR signaling pathway. This process induced autophagy, which essentially resulted in the apoptosis of GC cells. Results from subcutaneous implanted tumor models in nude mice also indicated that rafoxanide inhibited the growth of GC cells in vivo. Taken together, our findings revealed that rafoxanide inhibited the growth of GC cells both in vitro and vivo, indicating a potential drug candidate for the treatment of GC.