Activity In Gastric Adenocarcinoma Research Articles

Abstract 5939: Enhancing nab-paclitaxel chemotherapy response in gastric cancer preclinical models through Inhibition of the HGF/c-Met pathway with merestinib

Abstract Background: Current treatments for primary metastatic or recurrent gastric adenocarcinoma (GAC) primarily involve combination chemotherapy, but the median survival time remains under a year. Nab-paclitaxel has displayed significant antitumor activity in preclinical GAC studies. GAC often exhibits overexpression of various growth factors and their receptors, which play a critical role in its pathophysiology. Aberrant activation of the HGF/c-Met pathway has been reported in up to 50% of GAC patients. We investigated the therapeutic potential of merestinib, a novel inhibitor targeting c-Met, along with Axl and DDR1/2 pathways, in combination with nab-paclitaxel in GAC preclinical models. Methods: Animal survival studies were conducted using peritoneal dissemination xenografts in NOD/SCID mice implanted with MKN-45 cells. Tumor growth was assessed in subcutaneous xenografts using MKN-45 and SNU-1 cells in NOD/SCID mice. IHC analyses were performed to evaluate tumor cell proliferation and microvessel density. In vitro cell proliferation and protein expression were assessed using the WST-1 assay and Western blot analysis, respectively. Results: Animal survival significantly improved with nab-paclitaxel (118%) and merestinib (41%) individually. The combination of merestinib with nab-paclitaxel (153%) resulted in further increased animal survival. In MKN-45 xenografts with high c-Met expression, a substantial reduction in tumor growth was observed with nab-paclitaxel and merestinib, showing a synergistic response. The net change in tumor size in the control, nab-paclitaxel, merestinib, and combination groups was 503 mm3, 115 mm3, 91 mm3, and -9.7 mm3 (tumor regression). In low c-Met expressing SNU-1 xenografts, the effect of merestinib and nab-paclitaxel was less pronounced compared to MKN-45 xenografts. The net change in tumor size in the control, nab-paclitaxel, merestinib, and combination groups was 219 mm3, 105 mm3, 131 mm3, and 57 mm3. Tumor cell proliferation and microvessel density corroborated the tumor growth study results. Nab-paclitaxel and merestinib reduced in vitro cell proliferation, with an additive effect in combination. The reduction in cell proliferation by nab-paclitaxel (10 nM), merestinib (100 nM), and their combination was 87%, 82%, and 94% in MKN-45, 59%, 50%, and 82% in SNU-1, and 53%, 19%, and 66% in gastric fibroblasts. In MKN-45 cells, merestinib increased the expression of pro-apoptotic proteins and decreased the expression of phospho-c-Met, phospho-EGFR, phospho-IGF-1R, phospho-ERK, and phospho-AKT. Conclusion:Merestinib has strong antitumor activity in GAC, especially when administered with nab-paclitaxel, demonstrating a synergistic effect. These results provide compelling evidence for the potential clinical relevance of this combination therapy in improving the survival of GAC patients. Citation Format: Quinn Kaurich, Jennifer Huang, Sazzad Hassan, Urs von Holzen, Niranjan Awasthi. Enhancing nab-paclitaxel chemotherapy response in gastric cancer preclinical models through Inhibition of the HGF/c-Met pathway with merestinib [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5939.

Enhancing nanoparticle paclitaxel antitumor response through targeted inhibition of c-Met pathway by merestinib in gastric cancer models.

372 Background: Gastric adenocarcinoma (GAC) is the fifth most common malignancy and the third most common cause of cancer-related deaths worldwide. Combination chemotherapy regimens are commonly used to treat GAC, but the median survival time remains less than one year. Nanoparticle albumin-bound paclitaxel ( nab-paclitaxel, NPT), an approved treatment for breast cancer, non-small cell lung cancer and pancreatic cancer, has demonstrated high antitumor activity in previous GAC studies. Many growth factors and their receptors are overexpressed in GAC and have been implicated in its pathophysiology. Aberrant activation of the c-Met pathway has been reported in up to 50% of GAC patients. We hypothesize that merestinib, a small-molecule inhibitor of c-Met, with additional inhibition of Axl and DDR1/2 pathways, will have significant antitumor effects and will enhance nab-paclitaxel chemotherapy response in GAC preclinical models. Methods: GAC subcutaneous xenografts were established by injecting MKN-45 and SNU-1 cells in NOD/SCID mice to study treatment effects on tumor volume, tumor weight, net tumor growth, and mouse body weight. Immunohistochemistry analyses of xenograft tissues were performed using Ki67 and endomucin to examine tumor cell proliferation and microvessel density, respectively. Results: In vitro assays showed that nab-paclitaxel and merestinib decreased cell proliferation in all three GAC-associated cell lines tested, with an additive effect in combination. Reduction in cell proliferation at low doses of nab-paclitaxel (10 nM), merestinib (100 nM), and their combination was 87%, 82%, and 94% (MKN-45, high phospho-c-Met expression), 59%, 50%, and 82% (SNU-1, low phospho-c-Met expression), and 53%, 19%, and 66% in gastric fibroblasts. Immunoblot analysis of merestinib treated MKN-45 cells revealed increased expression of pro-apoptotic proteins and decreased expression of phospho-c-Met, phospho-EGFR, phospho-IGF-1R, phospho-ERK, and phospho-AKT. In gastric fibroblasts, merestinib decreased phospho-ERK and increased pro-apoptotic protein expression. Phospho-c-Met and phospho-EGFR were not detected in SNU-1 immunoblots; however, phospho-ERK, phospho-VEGFR, and apoptotic protein expression increased after treatment. In MKN-45 xenografts, net tumor growth in control, nab-paclitaxel, merestinib, and combination groups was 503 mm3, 115 mm3, 91 mm3, and -9.7 mm3. Immunohistochemistry analysis of tumor cell proliferation and microvessel density corroborated tumor growth study results. Conclusions: These findings suggest that merestinib has strong antitumor activity in GAC and exhibits an additive effect when administered with nab-paclitaxel. These results provide compelling evidence that this therapeutic approach may lead to a clinically relevant combination to improve GAC patients’ survival.

In silico design and in vitro assessment of anti-Helicobacter pylori compounds as potential small-molecule arginase inhibitors.

Related to a variety of gastrointestinal disorders ranging from gastric ulcer to gastric adenocarcinoma, the infection caused by the gram-negative bacteria Helicobacter pylori (H. pylori) poses as a great threat to human health; hence, the search for new treatments is a global priority. The H. pylori arginase (HPA) protein has been widely studied as one of the main virulence factors of this bacterium, being involved in the prevention of nitric oxide-mediated bacterial cell death, which is a central component of innate immunity. Given the growing need for the development of new drugs capable of combating the infection by H. pylori, the present work describes the search for new HPA inhibitors, using virtual screening techniques based on molecular docking followed by the evaluation of the proposed modes of interaction at the HPA active site. In vitro studies of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), followed by cytotoxicity activity in gastric adenocarcinoma and non-cancer cells, were performed. The results highlighted compounds 6, 11, and 13 as potential inhibitors of HPA; within these compounds, the results indicated 13 presented an improved activity toward H. pylori killing, with MIC and MBC both at 64µg/mL. Moreover, compound 13 also presented a selectivity index of 8.3, thus being more selective for gastric adenocarcinoma cells compared to the commercial drug cisplatin. Overall, the present work demonstrates the search strategy based on in silico and in vitro techniques is able to support the rational design of new anti-H. pylori drugs.

Anti-tumor activity of neratinib, a pan-HER inhibitor, in gastric adenocarcinoma cells

Gastric adenocarcinoma (GAC), the most common malignancy of the stomach, is the fourth most common and the second cause of cancer-related death worldwide. Although HER family plays a cardinal role in tumorigenesis of GAC, trastuzumab is the only approved anti-HER drug for this malignancy and development of resistance to trastuzumab is inevitable. Additionally, single-targeted HER inhibitors have demonstrated limited activity in GAC. Hence, there is a pressing need to devise more efficacious anti-HER therapeutic strategies. Here, we examined the anti-tumor activity of neratinb, a pan-HER inhibitor, on GAC cells. Anti-proliferative effects of neratinib were determined using a cell proliferation assay and crystal violet staining. Annexin V/PI staining, radiation therapy and anoikis resistance and wound healing assays were carried out to examine the effects of neratinib on apoptosis, radio-sensitivity and cell motility, respectively. Quantitative reverse transcription-PCR (qRT-PCR) analyses were applied to further investigate the anti-tumor activity of neratinib. We found that neratinib sensitized GAC cells to 5FU, carboplatin and oxaliplatin. Moreover, we found that neratinib was synergistic with trametinib (an approved MEK inhibitor) and foretinib (a c-MET inhibitor) and potentiated radio-sensitivity of GAC cells. Furthermore, we found that neratinib diminished GAC cell proliferation along with downregulation of FOXM1 and its targets. Additionally, neratinib induced apoptosis along with upregulation of pro-apoptotic and downregulation of anti-apoptotic genes. Treatment with neratinib attenuated invasive ability of GAC cells as shown by reduced anoikis resistance, downregulation of EMT markers, and reduced width in scratch assay. Our findings indicate that neratinib provides the therapeutic potential in the treatment of GAC.

Abstract 2061: A novel small molecule inhibitor of MDM2-p53 (APG-115) has antitumor activity in gastric adenocarcinoma

Abstract Background: The amplification of Murine Double Minute 2 (MDM2) and mutation of P53 are significant processes in the incidence of gastric cancer. APG-115, a small molecular inhibitor of MDM2-P53, is a novel potential anticancer agent. We aim to investigate the anticancer effect of APG-115 in gastric cancer. Methods: We selected 87 pairs of gastric cancer tissues (primary tumors and metastatic tissues). Using Immunohistochemistry (IHC) and Fluorescence in situ hybridization (FISH), we examined the expression and amplification of MDM2 and P53. Using MTS, we examined the anti-proliferation activity of APG-115 in five gastric cancer cell lines (AGS, MKN-45, BGC-823, NCI-N87, NUGC-3) by CCK-8 assay. We used western blot analysis and siRNA interference for mechanism exploration to examine the anti-cancer activity of APG-115 in p53 wild type gastric cancer cell lines. Gastric cancer cell xenograft nude mice models were used for in vivo efficacy evaluation. Results: We examined 87 pairs of gastric cancer tissues in IHC. The results suggested that the primary tumors and metastatic tissues with high expression of MDM2 and P53 have shortened survival. The proliferation inhibition of APG-115 on p53 wild-type gastric cancer cells of AGS and MKN45 was concentration and time dependent. APG-115 induced apoptosis in gastric cancer cells. APG-115 can induced cell-cycle arrest in G1/G0 phase in the p53 wild-type of gastric cancer cells. APG-115 exhibited potent antitumor activity against established human gastric cancer xenografts. Conclusions: APG-115 can inhibitor tumor growth in p53 wild-type gastric cancer cells by inducing apoptosis and cell cycle arrest both in vitro and vivo. APG-115 can serve as an effective and precise therapeutic strategy for gastric cancer. Citation Format: Lin Zhang, Luo Qiuyun, Yan Xianglei, Xueping Wan, Luping Yuan, Yuxing Zhang, Suna Zhou, Wentao Pan, Mengxian Pan, Miaozhen Qiu, Shijuan Mai, Dajun Yang. A novel small molecule inhibitor of MDM2-p53 (APG-115) has antitumor activity in gastric adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2061.

A Novel Small Molecule Inhibitor of MDM2-p53 (APG-115) Has Antitumor Activity in Gastric Adenocarcinoma

Gastric cancer (GC) is the third leading cause of cancer related death. APG-115, a novel MDM2-P53 inhibitor, is a potential anticancer agent. In this study, we aim to investigate the anticancer effect and mechanisms of APG-115 in GC. The anti-tumor activity of APG-115 was evaluated both in vitro and in vivo. Western blot analysis and siRNA interference for mechanism exploration of APG-115. We found that APG-115 exerted potent proliferation inhibition on p53 wild-type gastric cancer cells AGS and MKN-45 in a time-and dose-dependent manner. Besides, APG-115 could induce apoptosis and cell-cycle arrest in G1/G0 phase in the p53 wild-type gastric cancer cells. In vivo, APG-115 exhibited potent antitumor activity against human gastric cancer xenografts. Our data provide solid preclinical evidence that APG-115 can serve as an effective and precise therapeutic strategy for gastric cancer. Funding Statement: This work was supported by Natural Science Foundation of Guangdong Province, China (grant no. 2018A030310260); Medical Scientific Research Foundation of Guangdong Province, China (grant no. 2018102516469945); National Natural Science Foundation of China (Grant number. 81602066 and 81772587); the Fundamental Research Funds for the Central Universities (Grant number. 16ykpy25); the third outstanding young talents training plan and Medical Scientist program of Sun Yat-sen University cancer center; Science and Technology Planning Project of Guangzhou, China (Grant number. 201510161726583); National Science and Technology Major Project, China (Grant number. 2016ZX09101004). Declaration of Interests: The authors declare that they have no competing interests. Ethics Approval Statement: All animal experiments were performed under the guidance of Sun Yat-Sen University Committee for Use and Care of Laboratory Animals and approved by the animal experimentation ethics committee.

Polymorphisms in matrix metalloproteinases 2, 3, and 8 increase recurrence and mortality risk by regulating enzyme activity in gastric adenocarcinoma

The association of polymorphisms in matrix metalloproteinases (MMPs) with clinical outcomes of gastric adenocarcinoma has not been examined. Ten polymorphisms in MMP1, 2, 3, 7, 8, 9, 12, and 13 were genotyped and investigated, and patients were followed for an average of 58 months. The activities of MMP2, 3, and 8 were measured. Recurrence risk increased in patients with the MMP2 rs2285053 CC genotype (hazard ratio [HR], 1.85), MMP3 rs679620 AA genotype (HR, 2.15), and MMP8 rs1940475 TT genotype (HR, 2.22) on recurrence free survival (RFS). Co-presence of the unfavorable MMP2 rs2285053 CC and MMP8 rs1940475 TT genotypes resulted in an additional increased risk of recurrence (RFS: HR, 4.42; 95% confidence interval [CI], 2.15–9.09; p<0.0001) and risk of death (overall survival ( OS) : HR, 6.59; 95% CI, 3.15–13.19; p<0.0001). Theoretical survival tree analysis revealed that recurrence-free survival significantly varied from 15.5 to 87 months among patients with different polymorphisms in MMP2, 3, and 8. The enzymatic activities of MMP2 and MMP3 increased (MMP2 rs2285053 CC: 888.60 vs. CT: 392.00, p <0.0001; MMP3 rs679620 AA: 131.10 vs. GG: 107.74, p=0.015), whereas those of MMP8 decreased (MMP8 rs1940475 TT: 133.78 vs. CC: 147.54, p=0.011) in gastric cancer tissues. These results suggest that polymorphisms in MMP2, 3, and 8 may increase cancer recurrence and patient death by increasing or decreasing enzyme activity in patients with gastric adenocarcinoma.

Prognostic role of telomerase activity in gastric adenocarcinoma: A meta-analysis

Activation of telomerase is involved in carcinogenesis in most types of cancers. However, the prognostic value of telomerase activity (TA) in patients with gastric carcinoma (GC) remains controversial. We conducted a meta-analysis to assess the relationship between TA and the clinical outcome of GC. A meta-analysis of 18 studies (886 patients) was performed to evaluate the association between TA and metastasis-related parameters in GC patients by searching databases, including PubMed, MEDLINE, EMBASE, Web of Science databases, Cochrane Library and the Chinese Biomedical Literature database (CBM) (last search updated in October 2011). We used the odds ratios (ORs) with 95% confidence intervals (CIs) to assess the strength of the association between TA and metastasis of GC. Our analysis results indicated that high telomerase activity expression tended to be associated with the presence of lymph node metastasis (866 patients) (OR=2.03, 95% CI 1.21-3.39, p=0.007), the depth of invasion (886 patients) (OR=1.87, 95% CI 1.30-2.70, p=0.0007), distant metastasis (407 patients) (OR=2.71, 95% CI 1.59-4.63, p=0.0002), tumor size (466 patients) (OR=2.14, 95% CI 1.31-3.50, p=0.002) and TNM stage (711 patients) (OR=2.39, 95% CI 1.30-4.41, p=0.005). However, high TA expression was not associated with the presence of histologic differentiation (791 patients) (OR=1.51, 95% CI 0.73-3.11, p=0.26). In conclusion, telomerase overexpression not only plays a key role in primary initiation, but also promotes invasion and metastatic progression of GC. These findings raise the possibility of using TA to screen for the prognosis of gastric cancer.

A Loss of Smad2 dependent TGF-beta signaling correlates with poor differentiation in gastric cancer

Background: TGF-beta plays dual roles in progression of human cancer. In precancerous stages, TGF-beta acts as tumor suppressor by providing cytostatic downstream signaling, whereas in late cancer stages, it induces processes that support tumor progression, including stroma fibroblast activation, epithelial mesenchymal transition and metastasis. Due to the high complexity of the TGF-beta signaling pathway, molecular details of this dramatic functional switch are only poorly understood. Recently, a shift from Smad2/3 C-terminal to linker site phosphorylation was hypothesized as key event for the cancer facilitating outcome of TGF-beta in colorectal and hepatocellular carcinoma. In the present study, we investigated this assumption in gastric adenocarcinoma. Methods: Immunohistochemical staining with anti-P-Smad2/3C and p-Smad2/3L antibodies was performed with 130 paraffin-embedded gastric adenocarcinoma cancer specimen. Relationship of immunohistochemical score with clinicopathologic characteristics of these patients was estimated. Results: No significant P-Smad2L and/or P-Smad3L positive staining was found in the tested samples, neither from healthy controls nor from patients with gastric adenocarcinoma, whereas loss of P-Smad2C positive staining remarkably correlates with depth of tumor and differentiation of cancer in patients with gastric cancer. P-Smad3C staining did not significantly correlate with clinicopathologic gastric adenocarcinoma characteristics. However and interestingly, IHC score of P-Smad3C is associated with a-SMA positive cancer associated fibroblasts and P-Smad3C positive staining colocalised with a-SMA and collagen I expression in cancer cells. Conclusions: Smad2/3L phosphorylation does not occur in gastric cancer. Smad2 C-terminal phosphorylation mediated signaling may have important tumor preventing activity in gastric adenocarcinoma. Smad3 activation is not directly linked to clinical gastric cancer characteristics, however may participate in tumor stroma fibroblast activation and epithelial-to-mesenchymal transition of cancer cells in gastric cancer progression and metastasis.

HTERT mRNA Partially Regulates Telomerase Activity in Gastric Adenocarcinoma and Adjacent Normal Gastric Mucosa

The extent to which human telomerase reverse transcriptase (hTERT) mRNA and its splice variants control telomerase activity in human cancers is controversial. Telomerase and hTERT mRNA were assessed quantitatively in paired samples of gastric adenocarcinoma and adjacent normal tissue. Splice variants within the hTERT reverse transcriptase domain (alpha, beta, alphabeta) were detected by RT-PCR. In gastric adenocarcinoma, compared to normal tissue, median telomerase activity increased significantly (from 0 total product generated [tpg; 95% confidence interval CI, 0-2.3] to 16.1 tpg [95% CI, 3.7-97]; P = 0.008) and median hTERT mRNA levels also increased (from 2.21 [95% CI, 1.40-4.62] to 7.08 [95% CI, 3.26-10.8]; P = 0.0054). hTERT mRNA and telomerase activity correlated in normal gastric mucosa (r = 0.819, P = 0.0002). Alpha, beta, and alphabeta deletions were similar in both groups. We conclude that hTERT mRNA partially regulates telomerase activity in normal gastric mucosa and gastric adenocarcinoma. In contrast, hTERT mRNA splicing is not involved in the regulation of enzyme activity.

Cis-platinum as second-line chemotherapy in advanced gastric adenocarcinoma. A phase II study of the EORTC gastrointestinal tract cancer cooperative group

Thirty-four patients with measurable metastatic gastric adenocarcinoma refractory to prior chemotherapy were treated with cis-platinum 100 mg/m 2 in a 6-hr infusion at 3-week intervals. Thirty-one patients were evaluable for response. There were three complete and three partial responses. Median duration of response was 4 months. Toxicity consisted mainly of nausea and vomiting and was severe in 12 patients. One patient had a severe but reversible renal failure. These results confirm other data reported in the literature. Cis-platinum has activity in gastric adenocarcinoma and should now be further investigated in first-line chemotherapy.