Monoclonal antibodies-based treatment in gastric cancer: current status and future perspectives

Inhibition or Reversal of the Epithelial-Mesenchymal Transition in Gastric Cancer: Pharmacological Approaches

Epithelial-mesenchymal transition (EMT) constitutes one of the hallmarks of carcinogenesis consisting in the re-differentiation of the epithelial cells into mesenchymal ones changing the cellular phenotype into a malignant one. EMT has been shown to play a role in the malignant transformation and while occurring in the tumor microenvironment, it significantly affects the aggressiveness of gastric cancer, among others. Importantly, after EMT occurs, gastric cancer patients are more susceptible to the induction of resistance to various therapeutic agents, worsening the clinical outcome of patients. Therefore, there is an urgent need to search for the newest pharmacological agents targeting EMT to prevent further progression of gastric carcinogenesis and potential metastases. Therapies targeted at EMT might be combined with other currently available treatment modalities, which seems to be an effective strategy to treat gastric cancer patients. In this review, we have summarized recent advances in gastric cancer treatment in terms of targeting EMT specifically, such as the administration of polyphenols, resveratrol, tangeretin, luteolin, genistein, proton pump inhibitors, terpenes, other plant extracts, or inorganic compounds.

Umbelliprenin isolated from Ferula sinkiangensis inhibits tumor growth and migration through the disturbance of Wnt signaling pathway in gastric cancer

The traditional herb medicine Ferula sinkiangensis K. M. Shen (F. sinkiangensis) has been used to treat stomach disorders in Xinjiang District for centuries. Umbelliprenin is the effective component isolated from F. sinkiangensis which is particularly found in plants of the family Ferula. We previously reported the promising effects of Umbelliprenin against gastric cancer cells, but its anti-migration effect remained unknown. Here we investigated the anti-migration effect and mechanism of Umbelliprenin in human gastric cancer cells. In SRB assay, Umbelliprenin showed cytotoxic activities in the gastric cancer cell lines AGS and BGC-823 in a dose-and-time-dependent manner, while it showed lower cytotoxic activity in the normal gastric epithelium cell line GES-1. During transwell, scratch and colony assays, the migration of tumor cells was inhibited by Umbelliprenin treatment. In gelatin zymography assay, Umbelliprenin could inhibit the expression of MMP2 and MMP9 in tumor cells The expression levels of the Wnt-associated signaling pathway proteins were analyzed with western blots, and the results showed that Umbelliprenin decreased the expression levels of proteins of the Wnt signalling pathway, such as Wnt-2, β-catenin, GSK-3β, p-GSK-3β, Survivin and c-myc. The translocation of β-catenin to the nucleus was also inhibited by Umbelliprenin treatment. In TCF reporter assay, the transcriptional activity of T-cell factor/lymphoid enhancer factor (TCF/LEF) was decreased after Umbelliprenin treatment. The in vivo results suggested that Umbelliprenin induced little to no harm in the lung, heart and kidney. Overall, these data provided evidence that Umbelliprenin may inhibit the growth, invasion and migration of gastric cancer cells by disturbing the Wnt signaling pathway.

LncRNA GACAT3 acts as a competing endogenous RNA of HMGA1 and alleviates cucurbitacin B-induced apoptosis of gastric cancer cells

Long non-coding RNAs (lncRNAs) have been demonstrated to perform important roles in cancer development. Previously, we have shown that lncRNA gastric cancer-associated transcript 3 (GACAT3) is overexpressed in gastric cancer and acts as a downstream target of interleukin 6/signal transducer and activator of transcription 3 (IL-6/STAT3) signaling. However, the role of GACAT3 in regulating gastric cancer cell growth remains unclear. In this study, we demonstrate that GACAT3 acts as a competing endogenous RNA of high mobility group A1 (HMGA1), a typical oncogene that is overexpressed in most types of cancer, based on a search for common miRNA-binding sites and on experiments involving in vitro cell transfection with synthesized miRNA mimics. Furthermore, knockdown of GACAT3 by its specific siRNA resulted in significantly decreased cell proliferation in gastric cancer cells, similar to the effect of an HMGA1 knockdown. Moreover, GACAT3 overexpression alleviated the apoptosis induced by cucurbitacin B, which is a widely used anticancer drug. Mechanistically, GACAT3 amplified STAT3 expression and decreased the level of the apoptosis gene bcl-2-associated X protein (BAX). Thus, our study provides fundamental information regarding GACAT3, which could be a valuable target for gastric cancer therapy.

Docetaxel, oxaliplatin, 5FU, and trastuzumab as first-line therapy in patients with human epidermal receptor 2-positive advanced gastric or gastroesophageal junction cancer: Preliminary results of a phase II study

The aim of this study is to report first preliminary results of patients enrolled in a phase II study that will investigate the activity and safety of docetaxel, oxaliplatin, and 5-fluorouracil (DOF) in combination with trastuzumab in human epidermal receptor-2 (HER-2) positive patients with advanced gastric or gastroesophageal junction (GEJ) cancer.Treatment consisted of docetaxel 70 mg/m combined with oxaliplatin 130 mg/m on day 1, and continuous infusion 5-fluorouracil mg/m days 1-5 plus trastuzumab at the standard dose on day 1, every 3 weeks for a maximum of 8 cycles.Fifteen patients were enrolled. The overall response rate was 60%. The median progression-free survival was 9.2 months (95% confidence interval [CI], 4.4-10.1 months) and the median overall survival was 19.4 months (95% CI, 8.9-21.1 months). Grade 3 neutropenia was observed in 3 patients (20%).The DOF plus trastuzumab seems active in HER-2 positive advanced gastric or GEJ cancer, final results of the phase II study are awaited.

Association between ramucirumab-related hypertension and response to treatment in patients with metastatic gastric cancer

Purpose

Hypertension (HTN) is frequently associated with the use of angiogenesis inhibitors targeting the vascular endothelial growth factor pathway, such as ramucirumab. The aim of this study was to retrospectively evaluate if occurrence of HTN is correlated with response to second line treatment with ramucirumab+paclitaxel for metastatic gastric cancer.

Methods

Treatment consisted of ramucirumab 8 mg/kg intravenously (iv) on days 1 and 15, plus paclitaxel 80 mg/m² iv on days 1, 8, and 15 of a 28-day cycle. Patients received study treatment until disease progression, unacceptable toxicity, or withdrawal of consent.

Results

Thirty-four patients were retrospectively evaluated. Among these, 6 (17.6%) developed grade 3 ramucirumab-induced HTN. These patients had a better outcome than those with lesser grades events, with a progression-free survival (PFS) of 7.8 months (95% CI 4.4-not reached) versus 4.2 months (95% CI 3.1-5.2) (p=0.001). overall survival (OS) was 11.9 months (95% CI 9.3-not reached) in the grade 3 HTN group, versus 7.2 months (95% CI 5.9-10.1).

Conclusions

Despite the small number of patients and the retrospective nature of the data, our analysis showed that occurrence of ramucirumab-related HTN, in particular G3 HTN, predicts response to treatment with ramucirumab+paclitaxel in patients with metastatic gastric cancer.

KRAS Mutation in Gastric Cancer and Prognostication Associated with Microsatellite Instability Status

Microsatellite instability (MSI) is one of the subgroups based on the new molecular classification of gastric cancer (GC). In this study, we analyzed the role of KRAS status in MSI GC and the impact of MSI status on KRAS mutation. We performed analysis on 595 GC patients. Polymerase chain reaction (PCR) was used for the screening of KRAS mutation (exon 2) and 5 quasi-monomorphic mononucleotide repeats, namely, BAT-26, BAT-25, NR -24, NR-21, and NR-27 were used to determine the MSI status. The KRAS and MSI status were then compared with clinicopathologic data of the GC patients. MSI GC was found in 20.3% of all cases. KRAS mutation was seen in 24 patients; 18 were MSI (75%) and 6 were microsatellite stable (MSS) (25%). MSI GC patients with KRAS mutation were older and mostly female, but MSS presented more advanced T and N stage of the disease, more cardia tumors, and adjuvant treatment. Five-year survival was 72.2% for KRAS mutation patients with MSI and 0% for MSS (p < 0.001). Although KRAS mutations in GC are linked with MSI in the majority of cases, KRAS mutations with MSS status presented with a poor prognosis and a worse outcome. In multivariate analysis, MSI was associated with better survival (p < 0.001) but KRAS was with worse survival (p = 0.304). Our study suggests that KRAS mutations are based on MSI status rather than different codon subtypes of mutation, and such a division could be used to determine the GC patient outcome.

Risk of hypertension with ramucirumab-based therapy in solid tumors: data from a literature based meta-analysis

Ramucirumab is a monoclonal antibody against Vascular Endothelial Growth Factor Receptor-2 (VEGFR-2) approved for the treatment of several solid tumours. As shown in recent trials results, new-onset hypertension is one of the most frequent adverse events associated with ramucirumab therapy. Recent studies looked at the quantification of the risk of hypertension in patients receiving other anti-angiogenesis medications. We conducted a meta-analysis of randomized clinical trials with the aim to investigate the incidence and quantify the risk of new-onset hypertension of any grade in patients treated with ramucirumab. Our research suggests that hypertension is frequently associated with ramucirumab therapy, with an OR of 3.60 for any grade of hypertension and an even stronger correlation with grade 3-4 hypertension (OR 4.16). These data suggest that a strict monitoring, as well as early intervention protocols, are recommended in patients receiving the drug.

Targeting VEGFR-2 in Metastatic Gastric Cancer: Results From a Literature-Based Meta-Analysis

Angiogenesis is a key process in cancer development. We performed a meta-analysis to assess the efficacy and safety of the novel VEGFR-2 inhibitors in patients with metastatic gastric and gastroesophageal junction cancer. A literature-based meta-analysis of randomized controlled trials (RCTs) was undertaken. The primary outcome was the overall survival. The pooled analysis from RCTs on anti-VEGFR-2 inhibitors revealed a significant increase in overall survival (hazard ratio for death: 0.69, 95% confidence interval: 0.55-0.87; p = .002). This study confirms the efficacy of novel anti-VEGFR-2 inhibitors. The future studies of these agents will evaluate alone and in combination with chemotherapy the early line of treatment along with the identification of proper predictive biomarker.