Investigation of HER-2 codon 655 single nucleotide polymorphism frequency and c-ErbB-2 protein expression alterations in gastric cancer patients

SMPDL3B contributes to gastric adenocarcinoma cells progression by promoting the infiltration of M2 macrophages

Background/aim

The common disease gastric adenocarcinoma (GAC) has a high morbidity and mortality, so there is an urgent need for research to explore new diagnostic markers and therapeutic targets. This investigation was carried out to investigate the expression of sphingomyelin phosphodiesterase acid-like 3b (SMPDL3B) in GAC and its effects on tumor progression.

Materials and methods

Samples were collected from patients who underwent radical gastrectomy from January 2021 to December 2022. Along with the normal gastric epithelial cell lines GES-1 and SGC-7901, the AGS, MGC-803, and MSN-45 human gastric cancer cell lines were used to confirm SMPDL3B expression. RT-qPCR, Western blot, immunohistochemical, cell proliferation, assay of wound healing, transwell migration assay, invasion assay, flow cytometry, and immune evaluation experiments were carried out.

Results

SMPDL3B was found to be substantially expressed in GAC, and this condition has a bad prognosis. By establishing SMPDL3B knockdown and overexpression of GAC cell lines, this study confirmed that SMPDL3B promoted tumor cell proliferation, migration, and invasion. Additional bioinformatics research revealed a connection between SMPDL3B and immune cell infiltration in the GAC immunological microenvironment, which enhanced tumor cell proliferation by promoting the infiltration content of M2 macrophages.

Conclusion

This study determined the function of SMPDL3B for the clinical diagnosis, prediction, and novel management of GAC.

The Effect of HER2 Single Nucleotide Polymorphisms on Cervical Cancer Susceptibility and Survival in a Chinese Population

Background: Cervical cancer (CCa) is a multifactorial gynecologic disease worldwide. Effects of HER2 polymorphisms, especially those in exonic region, have been investigated in many gynecologic diseases. In this study, we evaluated the influence of functional HER2 polymorphisms on susceptibility and survival of CCa in a Chinese population.

Methods: We genotyped the HER2 exonic polymorphisms by TaqMan in both case-control study (413 CCa patients vs. 396 controls) and survival study (413 CCa patients). Logistic regression and Cox regression were adopted to evaluate the genetic association with the risk and outcomes of CCa, respectively.

Results: In the case-control study, there was no significant difference between patients and controls in either HER2 rs1136201 or rs1058808. However, when combined, these two polymorphisms demonstrated a significant hazardous effect for CCa (P = 0.012). Besides, number of variants was also influential (P trend =0.002). In survival analysis, dominant model of rs1136201 and co-dominant modelof rs1058808 were significantly associated with the survival (P = 0.037 and P =0.028). The combination of rs1136201 and rs1058808 also negatively impacted CCa survival (P = 0.009). Cox regression further revealed the significance of the polymorphism combination (β = 0.38, P = 0.025, HR= 1.47, 95%CI = 1.05-2.05). Functional assay of these polymorphisms demonstrated that rs1058808 G allele was associated with stronger expression of HER2 gene.

Conclusions: Our results suggested that the combination of HER2 rs1136201and rs1058808 was significantly associated with the susceptibility of CCa. Besides, this combination of polymorphism s also substantially impacted the survival of CCa patients.

Impact of HER2 codon 655 polymorphism and expression of HER2 and HER3 in non small cell lung cancer patients

The aim of the study was to assess the expression and significance of HER2 and HER3, and Ile/Val single nucleotide polymorphism (SNP) of HER2 in lung cancer patients. Thirty seven cases of lung cancer were investigated immunohistochemically for HER2 and HER3 expression. PCR followed by restriction fragment length polymorphism (RFLP) was used to analyze the presence of HER-2 SNP at codon 655 in 20 samples. The results were compared with clinical and pathological parameters of investigated patients.We found that 100% of the cases were negative for HER2, 29.7% were with moderate or strong HER3 expression and 70.3% of the tumors-without or with low expression for HER3. Lymph node metastasis were found in 40% of HER3 positive cases (χ(2) = 4.752; p = 0.029). Moderately-differentiated tumors do not express neither of investigated markers (χ(2) = 6.719; p = 0.035). HER2 RFLP-PCR analysis showed genotype AG in five patients (25%) and the rest of 15 cases (75%) had АА (Ile/Ile) genotype. Patients with metastasis had genotype АА (Ile/Ile) in 80% and genotype AG (Ile/Val) in 20% (χ(2) = 2.857; p = 0.091).Our results indicate that SNP in HER2 codon 655 and investigation of HER2 and HER3 expression could be helpful to outline the prognosis for patients with lung adenocarcinoma.

The prognostic significance of p21 and Her-2 gene expression and mutation/polymorphism in patients with gastric adenocarcinoma

Analyses of gene expression status and genetic polymorphisms are methods to identify novel histopathological prognostic factors. In patients with gastric cancer, some cell cycle regulators p53, p21, p27 and Her-2 oncogene have been proposed as prognostic factors. We aimed to investigate the expression and mutation/polymorphism of p21 and Her-2 and also relationship between that genes status and histopathological factors and prognosis in patients with gastric cancer. Forty-four patients with locally advanced gastric cancer were analyzed in this study from January 2000 to December 2008. Clinicopathological parameters, expression and mutation/polymorphism of p21 and Her-2 results were used to predict disease-free survival and overall survival. The positive expression of p21 and Her-2 was observed in 61.4 % (n = 27) and 9.1 % (n = 4) of all 44 tumors, respectively. p21 gene mutation and Her-2 gene polymorphism were detected in 20 % (n = 11) and 2.3 % (n = 1, II phenotype) of cases, respectively. The negative expression of p21 was correlated significantly with diffuse and undifferential type histologies, whole gastric involvement and positive vascular/neural invasion. The median survival rate of patients with negative expression was significantly poorer than that of patients with positive expression of p21 (17 vs. 27 months, p = 0.01, cox regression). p21 mutation was significantly higher in patients with diffuse (p = 0.03) and undifferential (p = 0.02) type histologies. There was no statistically significant association between histopathological parameters and Her-2 gene polymorphism/expression. The negative expression of p21 correlates with disease survival and may be a poor prognostic factor in patients with resected gastric cancer treated with adjuvant chemotherapy.

Prognostic significance of c-erbB2 overexpression in patients with metastatic gastric cancer

BACKGROUND

Overexpression of the gene c-erbB2, which encodes a receptor tyrosine kinase, has been associated with prognosis and response to therapy in several solid tumors. This study was designed to test whether c-erb-B2 overexpression can be related to prognosis of patients with metastatic gastric cancer.

METHODS

Between 2005 and 2010, 46 cases of metastatic gastric cancer were evaluated immunohistochemically for c-erb-B2 overexpression. Overall survival (OS) and time-to-progression (TTP) served as the main outcome measures.

RESULTS

c-erbB2 was overexpressed in 19 (41.3 %) cases and 8 patients (17.4 %) had a c-erbB2 score of 3+ (a strong complete membrane staining observed in >10 % of the tumor cells). c-erbB2 expression was not associated with the clinicohistological characteristics of the study participants. The mean OS was 11.48 ± 1.03 months, whereas the mean TTP was 8.28 ± 0.8 months. Compared with patients with a score of 2+ or less (n = 38), those with a c-erbB2 score of 3+ (n = 8) had both a significantly lower OS (15.55 ± 1.63 vs. 8.22 ± 0.88 months, respectively, p < 0.05) and TTP (10.72 ± 1.81 vs. 6.11 ± 0.61 months, respectively, p < 0.05). After allowance for potential confounders, Cox regression analysis identified a c-erbB2 score of 3+ as an independent predictor of both OS (hazard ratio = 1.9; 95 % confidence interval = 1.1-3.7, p < 0.05) and TTP (hazard ratio = 1.8; 95 % confidence interval = 1.1-4.1, p < 0.05).

CONCLUSION

Our results suggest that c-erbB-2 overexpression may have a prognostic significance in patients with metastatic gastric cancer.

Clinicopathologic factors associated with HER2-positive gastric cancer and its impact on survival outcomes--a systematic review

With the availability of a therapeutic target and an effective agent in trastuzumab, a systematic examination of the literature to investigate the role of human epidermal growth factor 2 (HER2) as a prognostic factor for survival and its association with clinicopathologic markers may improve treatment. An electronic search of the MEDLINE and PubMed databases (January 1990 to January 2011) was undertaken to identify translational studies that correlated HER2 with clinicopathologic markers and/or survival outcome. This review included 49 studies totaling 11,337 patients. Forty-four percent of patients had Stage I/II, and 56% had Stage III/IV disease. Immunohistochemistry was most commonly used to assess HER2 expression, identifying a median rate of 18% (range, 4-53%) of gastric cancer demonstrating HER2 overexpression. In patients with and without HER2 overexpression, the median 3-year disease-free survival rate was 58% (range, 50-88%) and 86% (range, 62-97%), respectively. Of the 35 studies reporting the impact of HER2 overexpression on survival, 20 studies (57%) reported no difference in overall survival, two studies (6%) reported significantly longer overall survival in patients with HER2 overexpression and 13 studies (37%) reported significantly poorer overall survival in patients with HER2 overexpression. The median overall survival and 5-year survival rate was 21 (range, 10-57) months and 42%, and 33 (range, 13-80) months and 52% in patients with and without HER2 overexpression, respectively. HER2 overexpression appears to be associated with poorer survival and with intestinal-type gastric cancer in this group of patients for whom majority undergone curative gastrectomy.

Wnt/β-catenin signaling enhances cyclooxygenase-2 (COX2) transcriptional activity in gastric cancer cells

Background

Increased expression of the cyclooxygenase-2 enzyme (COX2) is one of the main characteristics of gastric cancer (GC), which is a leading cause of death in the world, particularly in Asia and South America. Although the Wnt/β-catenin signaling pathway has been involved in the transcriptional activation of the COX2 gene, the precise mechanism modulating this response is still unknown.

Methodology/Principal Findings

Here we studied the transcriptional regulation of the COX2 gene in GC cell lines and assessed whether this phenomenon is modulated by Wnt/β-catenin signaling. We first examined the expression of COX2 mRNA in GC cells and found that there is a differential expression pattern consistent with high levels of nuclear-localized β-catenin. Pharmacological treatment with either lithium or valproic acid and molecular induction with purified canonical Wnt3a significantly enhanced COX2 mRNA expression in a dose- and time-dependent manner. Serial deletion of a 1.6 Kbp COX2 promoter fragment and gain- or loss-of-function experiments allowed us to identify a minimal Wnt/β-catenin responsive region consisting of 0.8 Kbp of the COX2 promoter (pCOX2-0.8), which showed maximal response in gene-reporter assays. The activity of this pCOX2-0.8 promoter region was further confirmed by site-directed mutagenesis and DNA-protein binding assays.

Conclusions/Significance

We conclude that the pCOX2-0.8 minimal promoter contains a novel functional T-cell factor/lymphoid enhancer factor (TCF/LEF)-response element (TBE Site II; -689/-684) that responds directly to enhanced Wnt/β-catenin signaling and which may be important for the onset/progression of GC.