Identifying Optimal Surgical Intervention-Based Chemotherapy for Gastric Cancer Patients With Liver Metastases

Carnosic acid nanocluster-based framework combined with PD-1 inhibitors impeded tumorigenesis and enhanced immunotherapy in hepatocellular carcinoma

Clinically, the immune checkpoint inhibitor anti-PD-1 antibody has shown a certain effect in the treatment of hepatocellular carcinoma (HCC), which is limited to a small number of patients with HCC. This study aims to reveal whether carnosic acid nanocluster-based framework (CA-NBF) has a sensitization effect on anti-PD-1 antibody in the treatment of HCC at the cellular and animal levels. MHCC97H cells were treated with CA-NBF, anti-PD-1 and their combination. The effects of CA-NBF and anti-PD-1 on cell proliferation, cell cycle, apoptosis, invasion, and migration were evaluated by MTT assay, flow cytometry, and scratch test. The effects of CA-NBF and anti-PD-1 on Wnt/β-catenin signaling pathway in MHCC97H cells were detected. A BALB/C nude mouse model of hepatocellular carcinoma was established, and the tumor growth was observed at different time points. The expression of cytotoxic T lymphocyte and helper T lymphocyte markers CD8 and CD4 in tumor tissues was detected by immunohistochemistry. Western blotting was used to detect the Wnt/β-catenin signaling pathway proteins (Wnt-3a, β-catenin, and GSK-3β) level in tumor tissues after CA-NBF and anti-PD-1 treatment. CA-NBF activity was significantly higher than CA, which could prominently reduce the proliferation, migration and invasion of MHCC97H cells and enhance apoptosis by inactivating Wnt/β-catenin signaling pathway. CA-NBF combined with anti-PD-1 antibody further enhanced cell proliferation, migration, invasion and pro-apoptosis but had no significant effect on Wnt/β-catenin signaling pathway. CA-NBF in vivo improved the tumor response to PD1 immune checkpoint blockade in HCC, manifested by reducing tumor size and weight, promoting CD4 and CD8 expression. CA-NBF combined with anti-PD-1 have stronger immunomodulatory and anticancer effects without increasing biological toxicity.

LncRNA CCAT2 promotes malignant progression of metastatic gastric cancer through regulating CD44 alternative splicing

OBJECTIVE

Gastric cancer (GC) is one of the most malignant tumors worldwide. Thus, it is necessary to explore the underlying mechanisms of GC progression and develop novel therapeutic regimens. Long non-coding RNAs (lncRNAs) have been demonstrated to be abnormally expressed and regulate the malignant behaviors of cancer cells. Our previous research demonstrated that lncRNA colon cancer-associated transcript 2 (CCAT2) has potential value for GC diagnosis and discrimination. However, the functional mechanisms of lncRNA CCAT2 in GC development remain to be explored.

METHODS

GC and normal adjacent tissues were collected to detect the expression of lncRNA CCAT2, ESRP1 and CD44 in clinical specimens and their clinical significance for GC patients. Cell counting kit-8, wound healing and transwell assays were conducted to investigate the malignant behaviors in vitro. The generation of nude mouse xenografts by subcutaneous, intraperitoneal and tail vein injection was performed to examine GC growth and metastasis in vivo. Co-immunoprecipitation, RNA-binding protein pull-down assay and fluorescence in situ hybridization were performed to reveal the binding relationships between ESRP1 and CD44.

RESULTS

In the present study, lncRNA CCAT2 was overexpressed in GC tissues compared to adjacent normal tissues and correlated with short survival time of patients. lncRNA CCAT2 promoted the proliferation, migration and invasion of GC cells. Its overexpression modulates alternative splicing of Cluster of differentiation 44 (CD44) variants and facilitates the conversion from the standard form to variable CD44 isoform 6 (CD44v6). Mechanistically, lncRNA CCAT2 upregulated CD44v6 expression by binding to epithelial splicing regulatory protein 1 (ESRP1), which subsequently mediates CD44 alternative splicing. The oncogenic role of the lncRNA CCAT2/ESRP1/CD44 axis in the promotion of malignant behaviors was verified by both in vivo and in vitro experiments.

CONCLUSIONS

Our findings identified a novel mechanism by which lncRNA CCAT2, as a type of protein-binding RNA, regulates alternative splicing of CD44 and promotes GC progression. This axis may become an effective target for clinical diagnosis and treatment.

Adjuvant Chemotherapy in pT2N0M0 Gastric Cancer: Findings From a Retrospective Study

Background: There is no global consensus on adjuvant chemotherapy (ACT) for pT2N0M0 gastric cancer. We conducted a retrospective study to reveal the role of ACT in such patients.

Methods: Patients with pT2N0M0 gastric cancer who underwent radical resection with D2 lymphadenectomy for primary gastric cancer between January 2012 and May 2016 were included. Kaplan–Meier and Cox regression were used to evaluate overall survival (OS), disease-specific survival (DSS) and predictors of prognosis. Stratified analysis based on high-risk factors was conducted.

Results: Of enrolled 307 patients, 111 patients underwent surgery alone and 196 patients received ACT. Surgery alone (HR = 2.913, 95% CI: 1.494-5.682, p = 0.002) and total gastrectomy (HR = 2.445, 95% CI: 1.279-4.675, p = 0.007) were independently associated with decreased OS. With the median follow-up of 73.1 months, the 5-year OS rate was 87.9% and 5-year DSS rate was 91.8%. Patients receiving ACT showed a better 5-year OS rate (92.9 vs. 79.3%, p < 0.001) and DSS rate (96.8 vs. 83.0%, p < 0.001) than patients underwent surgery alone. Patients receiving monotherapy (n = 130) had a relatively poor prognosis compared to patients receiving dual-drug (n = 66) without a significant difference (92.3 vs. 93.9%, p = 0.637). In patients without high-risk factors based on the Chinese Society of Clinical Oncology (CSCO) Guidelines, ACT also provided survival benefit (96.0 vs 82.9%, p = 0.038).

Conclusions: ACT was accompanied with higher 5-year OS and DSS rates of patients with pT2N0M0 gastric cancer. Patients with pT2N0M0 gastric cancer, regardless of high-risk factors based on the CSCO guidelines, might be considered candidates for ACT. In regard to the therapy regimen, monotherapy might be the optimal choice, considering the adverse events.