A more common and noninvasive predicting biomarker for programmed cell death 1 (PD-1) antibody remains to be explored. We assessed 46 patients with advanced gastric cancer who received PD-1 antibody immunotherapy and 425-genes next-generation sequencing (NGS) testing. Patients who had a > 25% decline in maximal somatic variant allelic frequency (maxVAF) had a longer progression free survival (PFS) and higher response rate than those who did not (7.3 months vs 3.6 months, p = 0.0011; 53.3% vs 13.3%, p = 0.06). The median PFS of patients with undetectable and detectable post-treatment circulating tumor DNA (ctDNA) was 7.4 months vs. 4.9 months (p = 0.025). Mutation status of TGFBR2, RHOA, and PREX2 in baseline ctDNA influenced the PFS of immunotherapy (p < 0.05). Patients with alterations in CEBPA, FGFR4, MET or KMT2B (p = 0.09) gene had greater likelihood of immune-related adverse events (irAEs). ctDNA can serve as a potential biomarker of the response to immunotherapy in advanced gastric cancers, and its potential role in predicting irAEs worth further exploration.

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BackgroundHepatitis B virus (HBV) infection is a major risk factor which can lead to development of hepatocellular carcinoma (HCC). In this study, we aimed to explore the effects of toll-like receptor 4 (TLR4) downregulation on the growth and survival of HBV-related HCC cells and to examine the molecular mechanisms been involved.MethodsThe expression levels of TLR4 were examined in a panel of HCC cell lines (HepG2, SMMC7721, Huh7, HepG2.2.15 and Hep3B). The effects of TLR4 downregulation on the proliferation, apoptosis, and tumorigenicity of HBV-related HepG2.2.15 cells were determined. The effects of TLR4 downregulation on multiple signaling pathways were also measured. Co-immunoprecipitation and immunofluoresence staining assays were performed to investigate the interaction between TLR4 and HBV X protein (HBx).ResultsThe mRNA and protein levels of TLR4 were significantly increased in HepG2.2.15 cells than those in the other cells which have been studied. Downregulation of TLR4 significantly decreased the proliferation and induced G2/M cell cycle arrest and apoptosis in HepG2.2.15 cells. TLR4 depletion inhibited HepG2.2.15 cell colony formation and tumor growth in nude mice. TLR4 silencing decreased the phosphorylation of ERK1/2 but not JNK1/2, p38, or NF-κB. Chemical inhibition of ERK1/2 approximately phenocopied the growth-suppressive effect of TLR4 downregulation on HepG2.2.15 cells. In addition, TLR4 showed a physical interaction with HBx.ConclusionsTaken together, TLR4 plays a tumor-promoting role in HBV-related HCC cells, which is associated with regulation of ERK1/2 activation and interaction with HBx. Therefore, TLR4 may be a potential therapeutic target for HBV-related HCC.

IL-4R plays an important role in regulating HCC cell survival and metastasis, and regulates the activity of the JAK1/STAT6 and JNK/ERK1/2 signaling pathways. We therefore suggest that IL-4/IL-4R may be a new therapeutic target for HCC.

e12567 Background: Several studies has showed alterations in genes were associated with endocrine resistance in breast cancer. Nevertheless, genomic landscape in primary endocrine-resistant breast cancer has not been thoroughly reported. Whether the genomic landscape of primary endocrine-resistant breast cancer is different from that of secondary endocrine-resistant breast cancer is unknown. Methods: We analyzed the genomic landscape of primary tumor of consecutive patients with estrogen-receptor positive (ER+) breast cancer in real-world clinical practice in our center between September, 2019 to December, 2020. According to the duration of endocrine treatment, we classified them into primary endocrine resistance group and secondary endocrine resistance group. Results: A total of 41 tumor samples of which 25 cases in primary endocrine resistance and 16 cases in secondary endocrine resistance were included for analysis. TP53 (65.9%, 27/41), PIK3CA (46.3%, 19/41), MYC (36.6%, 15/41), MCL1 (31.7%, 13/41), CCND1 (31.7%, 13/41) were the most frequently altered genes in all 41 BCs. Copy number amplification of MYC was common in primary endocrine resistant group (48.0%, 12/25), while lower in secondary endocrine resistant group (18.8%, 3/16, P = NS). Copy number alteration (CNA) of CCND1, MCL1, FGF19, ZNF217, ZNF703 and FGFR1 were commonly observed in primary endocrine resistance group. Percentage of CNA in all mutation types was significant increased in primary endocrine resistance group than in secondary resistance group (33.0% vs. 21.0%, P = 0.03). Then we further analyzed and found CNA burden, which was defined as number rather the percentage of the CNA event, was associated with the prognosis in ER+ breast cancer. When defining 6 as the cut-off value of CNA-High, DFS, PFS and OS were practically poorer in patients with CNA-High than those with CNA-Low. Conclusions: Copy number alterations were more commonly seen in primary endocrine-resistant breast cancer and associated with prognosis in ER+ breast cancer. This founding urged to further investigate the prognostic value of CNA burden in predicting the effectiveness of endocrine therapy.