Immunohistochemical Expression of Epithelial-Mesenchymal Transition Markers in Early Gastric Cancer: Cancer Tissue versus Noncancer Tissue

Gastric Carcinoma with low ROR alpha, low E- Cadherin and High LAPTM4B Immunohistochemical Profile; is associated with unfavorable prognosis in Egyptian patients

In view of multiplicity of carcinogenic pathways of gastric carcinoma (GC), poor survival and chemotherapy resistance, more analysis of these pathways is required for prediction of prognosis and developing new therapeutic targets. Knocking down of RORα; induces tumor cell proliferation and epithelial-mesenchymal transition (EMT). LAPTM4B has been suggested to be associated with EMT which promote tumor invasion. This work aimed to investigate prognostic role of RORα, LAPTM4B, and E-Cadherin expression in GC. This retrospective immunohistochemical study assesses the expression of RORα, LAPTM4B, and E-Cadherin in 73 primary gastric carcinomas. Low RORα and high LAPTM4B expression in GC cases were associated with unfavorable prognostic factors such as positive lymph nodes, and high tumor budding. E-Cadherin heterogeneous staining was associated with poor prognostic criteria, such as diffuse type GC and high tumor budding. Low RORα, high LAPTM4B, and heterogeneous E-Cadherin were the most common immunohistochemical profile in GC cases. Low RORα expression showed poor prognostic impact on overall patient survival. In conclusion, RORα and LAPTM4B may have crucial role in GC aggressiveness. The predominance of low RORα, high LAPTM4B, and heterogeneous or negative E-Cadherin immunohistochemical profile in GC cases with unfavorable pathological parameters suggested that this profile may predict tumor behavior.

Gastric Carcinoma with low ROR alpha, low E- Cadherin and High LAPTM4B Immunohistochemical Profile; is associated with poor prognosis in Egyptian patients.. [DOI: 10.21203/rs.3.rs-2123133/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Background Gastric carcinoma (GC) is the tenth most prevalent cancer in both sexes in Egypt. Many pathways have been investigated regarding pathogenesis of GC, including epithelial-mesenchymal transition (EMT) pathway. In view of multiplicity of carcinogenic pathways, poor survival and chemotherapy resistance detected in GC patients, more analysis of these pathways is required for better molecular selection of patients, prediction of prognosis and developing new therapeutic targets. Down-regulation of E-Cadherin is an important EMT stage. RORα is a tumor suppressor gene, expressed in normal epithelial tissues and reduced in a variety of human cancers. Knocking down of RORα; increase cell proliferation, EMT, migration, and invasion. LAPTM4B is a protooncogene and it has been suggested to be strictly associated with EMT induction. Therefore, this work aims to investigate the role of RORα, LAPTM4B and E-Cadherin and its relationship to prognosis of GC. Methods This is a retrospective study where the standard immunohistochemical technique was done to assess the expression of RORα, LAPTM4B and E-Cadherin in 167 cases of chronic gastritis (control group) and 73 primary gastric carcinomas (51 of them have available adjacent non tumor tissue). Results Low RORα and high LAPTM4B expression in GC cases were associated with unfavorable prognostic factors such as positive lymph nodes, and high tumor budding. E-Cadherin Heterogeneous staining was associated with poor prognostic pathological criteria, such as diffuse type GC and high tumor budding. In GC, there was significant co parallel correlation between RORα and E-Cadherin expression while LAPTM4B showed inverse correlation with E-Cadherin expression. Low RORα, high LAPTM4B, and negative or heterogeneous E-Cadherin were the most common immunohistochemical profile in GC cases. Low RORα expression showed poor prognostic impact on overall patient survival. Conclusions Low RORα H-score and increased expression of LAPTM4B were significantly associated with unfavorable prognostic parameters of GC which may indicate their crucial role in tumor aggressiveness. The predominance of low RORα, high LAPTM4B and heterogeneous or negative E-Cadherin immunohistochemical profile in GC cases with unfavorable pathological parameters suggested that this profile may predict tumor behavior and this profile could be linked to EMT molecular subtype of GC

MiR-522-3p Targets Transcription Factor 4 to Overcome Cisplatin Resistance of Gastric Cells

Gastric cancer (GC) is a malignancy originating from gastric epithelial tissue. Chemoresistance to cisplatin (DDP) often leads to chemotherapy failure in GC. Previously, miR-522 was found to be associated with chemoresistance in GC cells. Thus, we attempted to clarify miR-522-3p's role underlying chemoresistance of GC cells. RT-qPCR measured the miR-522-3p levels in untreated and DDP-treated AGS cells. RT-qPCR and Western blotting detected transcription factor 4 (TCF4) mRNA and protein levels in GC cells. AGS and AGS/DDP cell proliferation were detected by the colony formation assay. Flow cytometry analysis detected AGS and AGS/DDP cell apoptosis. Bioinformatics and dual luciferase reporter assays predicted and verified the relationship between miR-522-3p and TCF4. Rescue experiments further clarified the regulatory patterns of miR-522-3p/TGF4 in GC cells. miR-522-3p presented a downregulation in GC cells and was positively affected by DDP. TCF4 presented elevation in GC cells and was negatively affected by DDP. Mechanistically, miR-522-3p targeted TCF4 to suppress TCF4 gene expression. miR-522-3p overexpression suppressed GC cell proliferation and resistance to DDP and GC cell apoptosis was facilitated. TCF4 overexpression facilitated GC cell proliferation and resistance to DDP while repressing GC cell apoptosis. TCF4 elevation rescued changes in GC cell proliferation, apoptosis, and chemoresistance due to miR-522-3p overexpression. To sum up, miR-522-3p suppresses GC cell malignancy and resistance to DDP via targeting TCF4. Our research may provide a new biomarker for GC diagnosis and a novel direction for GC chemotherapy.

Investigating Helicobacter pylori-related pyloric hypomotility: functional, histological, and molecular alterations

Multiple theories have been proposed describing the pathogenic mechanisms of Helicobacter pylori (H. pylori)-associated gastric motility disorders. We assessed ex vivo pyloric activity in H. pylori-infected rats, and tried to explore the associated ghrelin hormone alteration and pyloric fibrogenesis. In addition, miR-1 was assessed in pyloric tissue samples, being recently accused of having a role in smooth muscle dysfunction. Ninety adult male Wistar albino rats were assigned into nine groups: 1) control group, 2) sterile broth (vehicle group), 3) amoxicillin control, 4) omeperazole control, 5) clarithromycin control, 6) triple therapy control, 7) H. pylori- group, 8) H. pylori-clarithromycin group, and 9) H. pylori-triple therapy group. Urease enzyme activity was applied as an indicator of H. pylori infection. Ex vivo pyloric contractility was evaluated. Serum ghrelin was assessed, and histological tissue evaluation was performed. Besides, pyloric muscle miR-1 expression was measured. The immunological epithelial to mesenchymal transition (EMT) markers; transforming growth factor β (TGFβ), α-smooth muscle actin (α-SMA), and E-cadherin-3 were also evaluated. By H. pylori infection, a significant (P < 0.001) reduced pyloric contractility index was recorded. The miR-1 expression was decreased (P < 0.001) in the H. pylori-infected group, associated with reduced serum ghrelin, elevated TGFβ, and α-SMA levels and reduced E-cadherin levels. Decreased miR-1 and disturbed molecular pattern were improved by treatment. In conclusion, H. pylori infection was associated with reduced miR-1, epithelial to mesenchymal transition, and pyloric hypomotility. The miR-1 may be a target for further studies to assess its possible involvement in H. pylori-associated pyloric dysfunction, which might help in the management of human H. pylori manifestations and complications.NEW & NOTEWORTHY This work is investigating functional, histopathological, and molecular changes underlying Helicobacter pylori hypomotility and is correlating these with miR-1, whose disturbance is supposed to be involved in smooth muscle dysfunction and cell proliferation according to literature. Epithelial to mesenchymal transition and reduced ghrelin hormone may contribute to H. pylori infection-associated hypomotility. H. pylori infection was associated with reduced pyloric miR-1 expression. Targeting miR-1 could be valuable in the clinical management of pyloric hypofunction.

Engulfment and cell motility 1 promotes tumor progression via the modulation of tumor cell survival in gastric cancer

BACKGROUND/AIM

Engulfment and cell motility 1 (ELMO1) protein has been implicated in phagocytosis of apoptotic cells, cell migration, neurite outgrowth, cancer cell invasion and metastasis, and poor prognosis in various cancers. We investigated the role of ELMO1 in mediating the oncogenic behavior of gastric cancer (GC) cells. We also investigated the correlation between expression of ELMO1 in GC tissues and various clinicopathological parameters.

METHODS

We studied the impact of ELMO1 on tumor cell behavior using the pcDNA-myc vector and small interfering RNA in AGS and SNU1750 GC cell lines. We performed western blotting and immunohistochemistry to investigate the expression of ELMO1 in GC cells and tissues.

RESULTS

ELMO1 overexpression inhibited apoptosis via the modulation of PARP, caspase-3 and caspase-7 in GC cells. ELMO1 overexpression led to significant increase in the number of migrating and invading GC cells. The expression of E-cadherin decreased and that of Snail increased in GC cells upon ELMO1 overexpression. Phosphorylation of PI3K/Akt and GSK-3β was increased and that of β-catenin was decreased upon ELMO1 overexpression in GC cells. These results were reversed after ELMO1 knockdown. ELMO1 expression was significantly associated with tumor size, cancer stage, lymph node metastasis and survival. ELMO1-positive tumors had significantly higher mean of Ki-67 labeling index than ELMO1-negative tumors. There was no significant relationship between ELMO1 expression and the mean value of the apoptotic index.

CONCLUSIONS

Our results indicate that ELMO1 promotes tumor progression by modulating tumor cell survival in human GC.