The miR-567/RPL15/TGF-β/Smad axis inhibits the stem-like properties and chemo-resistance of gastric cancer cells

Clinical significances of RPL15 gene expression in circulating tumor cells of patients with breast cancer

The preferred biomarkers for evaluating the outcomes of patients with breast cancer (BC) remain poorly understood. The present study aimed to investigate the predictive roles of circulating tumor cells (CTCs) and ribosomal protein L 15 (RPL15) expression in the prognosis of patients with BC. A total of 170 patients were included in the present study, all of whom were female. BC was diagnosed by combining clinical features, imaging and pathological findings. CanPatrol™ technology and triple color in situ RNA hybridization were used to detect CTC subtypes and RPL15 gene expression levels. CTCs were classified into epithelial CTCs, mesenchymal CTCs (MCTCs), and hybrid CTCs (HCTCs) according to cellular surface markers. Risk factors for recurrence and metastasis were validated by a multivariate COX regression model. Kaplan-Meier survival curves were used to determine the progression-free survival (PFS) of patients. The results showed that patients with advanced tumor-node-metastasis stage and triple negative BC had high MCTCs, HCTCs and RPL15 levels (P<0.05). Furthermore, the multivariate COX regression analysis revealed that MCTCs, HCTCs, HER2+ and positive RPL15 gene expression were key factors for recurrence and metastasis of patients (P<0.05). The PFS of patients with >2 MCTCs/5 ml blood, >5 HCTCs/5 ml blood, and positive RPL15 gene expression in CTCs were significantly shorter than that of patient with 2 MCTCs, 5 HCTCs, and negative RPL15 gene expression in CTCs (P<0.05). By contrast, the PFS of patients with positive HER2 also was significantly shorter than that of patients with negative HER2. Overall, the present data indicated that the PFS of patients with BC with >2 MCTC or >5 HCTCs, and positive RPL15 gene expression was shorter than that of those with 2 MCTCs or 5 HCTCs, and negative RPL15 gene expression. Additionally, the prognosis of patients with BC with negative HER2 is more favorable than the prognosis of patients with positive HER2 expression.

GDF6 in gastric cancer upregulated by helicobacter pylori induces epithelial-mesenchymal translation via the TGF-β/SMAD3 signaling pathway

OBJECTIVE

To investigate the association between Helicobacter pylori infection and GDF6 expression in gastric cancer patients, and to determine its influence on prognosis and resistance to capecitabine.

METHODS

Tumor and adjacent non-tumor tissues were collected from 148 gastric cancer patients who underwent surgery in our department from October 2019 to June 2022. Of these patients, 78 tested positive for Helicobacter pylori and 70 tested negative. Hematoxylin-eosin (HE) and immunofluorescence staining were utilized to quantify GDF6 expression in cancerous and adjacent tissues. Patient prognosis was monitored via follow-up. Western blotting analyzed GDF6 expression in common gastric cancer cell lines. HGC27 cells exhibiting high GDF6 expression and BGC823 cells with low expression were used to create GDF6-silenced and overexpressed cell lines. The impact of GDF6 on the proliferation, migration, invasion, and cloning abilities of gastric cancer cells was evaluated using the CCK-8 assay, scratch test, Transwell assay, and plate colony formation assay. Fluorescent quantitative PCR and Western blotting assessed the effects of GDF6 levels on epithelial-mesenchymal transition (EMT) and tumor cell stemness.

RESULTS

GDF6 expression in gastric cancer tissues was significantly correlated with cancer grading and staging (P<0.05). Helicobacter pylori-positive tissues exhibited significantly higher GDF6 expression levels than negative samples (P<0.05). Kaplan-Meier survival analysis indicated that high GDF6 expression was associated with poor survival prognosis. Overexpressed GDF6 enhanced the proliferation, migration, and invasion abilities of gastric cancer cells, while silencing GDF6 yielded opposite results. Increased GDF6 expression upregulated TGF-β expression and the phosphorylation levels of SMAD3, leading to an elevation in mesenchymal cell markers N-cadherin, vimentin, and a reduction in epithelial cell markers cytokeratins, E-cadherin. Moreover, high GDF6 levels contributed to increased resistance to capecitabine and enhanced the expression of tumor stem cell markers Nanog, Sox-2, Oct-4, CD44, amplifying tumor cell stemness.

CONCLUSION

Helicobacter pylori infection is associated with increased GDF6 expression in gastric cancer tissue, correlating with poor survival prognosis. Elevated GDF6 expression promotes the proliferation, migration, and invasion abilities of gastric cancer cells, facilitates EMT via the TGF-β/SMAD3 pathway, and intensifies cell stemness and capecitabine resistance. Consequently, GDF6 presents itself as a potential new target for gastric cancer treatment.

DATA AVAILABILITY STATEMENT

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Non-Coding RNA as Biomarkers and Their Role in the Pathogenesis of Gastric Cancer-A Narrative Review

Non-coding RNAs (ncRNAs) represent a broad family of molecules that regulate gene expression, including microRNAs, long non-coding RNAs and circular RNAs, amongst others. Dysregulated expression of ncRNAs alters gene expression, which is implicated in the pathogenesis of several malignancies and inflammatory diseases. Gastric cancer is the fifth most frequently diagnosed cancer and the fourth most common cause of cancer-related death. Studies have found that altered expression of ncRNAs may contribute to tumourigenesis through regulating proliferation, apoptosis, drug resistance and metastasis. This review describes the potential use of ncRNAs as diagnostic and prognostic biomarkers. Moreover, we discuss the involvement of ncRNAs in the pathogenesis of gastric cancer, including their interactions with the members of major signalling pathways.

Ginsenoside Rh1 regulates gastric cancer cell biological behaviours and transplanted tumour growth in nude mice via the TGF-β/Smad pathway

Gastric cancer (GC) is one of the most prevalent malignancies of the digestive tract. Ginsenoside Rh1 was reported to exert effects on GC. The current study set out to explore the mechanism underlying Ginsenoside Rh1 effects on GC. With oxaliplatin (OXA) serving as the positive control, human GC cells AGS were treated with 0, 10, 25, 50, 74, or 100 μM of ginsenoside Rh1 for 48 h. Proliferation, migration, invasion, and apoptosis were subsequently assessed by means of MTT, scratch test, Transwell, and TUNEL, respectively. AGS cells were further jointly treated with Rh1 and the TGF-β/Smad pathway activator Kartogenin, followed by detection of TGF-β/Smad pathway effects on AGS biological behaviours. Moreover, TGF-β/Smad pathway activation was detected with a Western blot assay. Furthermore, xenograft tumour models were established and tumour growth was recorded. Ki-67 expression patterns and apoptosis were detected with immunohistochemistry and TUNEL, respectively. In vitro, Ginsenoside Rh1 repressed AGS cell proliferation, migration, and invasion, and further promoted apoptosis, with a concentration of 50 μM Rh1 exerting the equivalent effects as OXA. In vivo, Ginsenoside Rh1 inhibited GC proliferation and induced tumour cell apoptosis. Mechanistically, Ginsenoside Rh1 reduced TGF-β1 and TGF-β2 levels and Smad2 and Smad3 phosphorylation levels. Collectively, our findings highlighted that ginsenoside Rh1 inhibited GC cell growth and tumour growth in xenograft tumour models via inhibition of the TGF-β/Smad pathway.