Use of Immunohistochemical p53 Mutant-Phenotype in Diagnosis of High-Grade Dysplasia of Esophageal Squamous Epithelia.

BACKGROUND: Mild cellular atypia of esophageal squamous epithelial dysplasia has a risk of progressing to cancer that poses great confusion for pathological diagnosis. There is no research on the diagnosis and differential diagnosis of esophageal squamous dysplasia by the expression of immunohistochemical (IHC) p53. The study aims to conduct a graded diagnosis of esophageal squamous epithelial hyperplasia by combining p53 expressions and microscopic histomorphological characteristics. METHODS: The study was conducted from January 2021 to January 2022 and included a total of 208 cases including 262 specimens with atypical hyperplasia or dysplasia of squamous epithelia discovered by esophageal mucosal biopsy. HE staining was used to grade the epithelial hyperplasia degree, and all cases underwent p53 IHC evaluation. RESULTS: Benign lesions: we did not find any p53 IHC mutant-phenotype (0/12 cases) in 12 cases of esophagitis. We found 10 cases (10/80 cases) of p53 IHC mutant-phenotype in 80 cases of low-grade dysplasia, and 158 cases (158/170 cases) of p53 IHC mutant-phenotype of high-grade lesions in 170 cases of high-grade dysplasia and early cancer based on the χ2 test results. We found statistically significant differences in p53 IHC mutant-phenotype between the high-grade squamous epithelial lesions and benign lesions. The sensitivity and specificity of p53 in detecting high-grade squamous epithelial lesions were 92.9% and 89.1%, respectively. The positive predictive value was 94.0%, and the negative predictive value was 87.2%. CONCLUSION: In this study, we found that p53 IHC had high sensitivity and specificity in detecting high-grade esophageal squamous epithelial lesions. Therefore, it has potential to be used as a routine item in pathological detection for auxiliary risk stratification of esophageal squamous epithelial lesions.

Exosomal DLX6-AS1 from hepatocellular carcinoma cells induces M2 macrophage polarization to promote migration and invasion in hepatocellular carcinoma through microRNA-15a-5p/CXCL17 axis.

BACKGROUND: Hepatocellular carcinoma (HCC) cells-secreted exosomes (exo) could stimulate M2 macrophage polarization and promote HCC progression, but the related mechanism of long non-coding RNA distal-less homeobox 6 antisense 1 (DLX6-AS1) with HCC-exo-mediated M2 macrophage polarization is largely ambiguous. Thereafter, this research was started to unearth the role of DLX6-AS1 in HCC-exo in HCC through M2 macrophage polarization and microRNA (miR)-15a-5p/C-X-C motif chemokine ligand 17 (CXCL17) axis. METHODS: DLX6-AS1, miR-15a-5p and CXCL17 expression in HCC tissues and cells were tested. Exosomes were isolated from HCC cells with overexpressed DLX6-AS1 and co-cultured with M2 macrophages. MiR-15a-5p/CXCL17 down-regulation assays were performed in macrophages. The treated M2 macrophages were co-cultured with HCC cells, after which cell migration, invasion and epithelial mesenchymal transition were examined. The targeting relationships between DLX6-AS1 and miR-15a-5p, and between miR-15a-5p and CXCL17 were explored. In vivo experiment was conducted to detect the effect of exosomal DLX6-AS1-induced M2 macrophage polarization on HCC metastasis. RESULTS: Promoted DLX6-AS1 and CXCL17 and reduced miR-15a-5p exhibited in HCC. HCC-exo induced M2 macrophage polarization to accelerate migration, invasion and epithelial mesenchymal transition in HCC, which was further enhanced by up-regulated DLX6-AS1 but impaired by silenced DLX6-AS1. Inhibition of miR-15a-5p promoted M2 macrophage polarization to stimulate the invasion and metastasis of HCC while that of CXCL17 had the opposite effects. DLX6-AS1 mediated miR-15a-5p to target CXCL17. DLX6-AS1 from HCC-exo promoted metastasis in the lung by inducing M2 macrophage polarization in vivo. CONCLUSION: DLX6-AS1 from HCC-exo regulates CXCL17 by competitively binding to miR-15a-5p to induce M2 macrophage polarization, thus promoting HCC migration, invasion and EMT.

Circ_SPECC1 enhances the inhibition of miR-526b on downstream KDM4A/YAP1 pathway to regulate the growth and invasion of gastric cancer cells.

Gastric cancer (GC) is a common malignant tumor, and many studies have shown that circular RNAs (circRNAs) play important roles in the progress of GC. This study showed that circ_SPECC1 was down-regulated in various GC cell lines, significantly inhibited GC cell proliferation and invasion, and promote apoptosis, which might play an anti-oncogene role. Circ_SPECC1 was mainly located in the cytoplasm, and its sequence contained multiple potential binding sites of miR-526b. Pull-down experiments with biotinylated miR-526b mimics and circ_SPECC1 probe showed that they could enrich each other. RIP experiments found hat anti-AGO2 antibody could significantly enrich circ_SPECC1. Further dual luciferase reporter gene assay also confirmed that miR-526b could bind directly to circ_SPECC1. miR-526b was also down-regulated in GC cells, and one of its important target genes was KDM4A. Both circ_SPECC1 and miR-526b inhibited the expression of KDM4A and its downstream effector YAP1, but miR-526b inhibitors terminated the above-mentioned inhibition of circ_SPECC1, and KDM4A overexpression reversed the inhibition of circ_SPECC1 and miR-526b on YAP1 expression. Both miR-526b and KDM4A siRNA inhibited GC cell proliferation and invasion, and promote apoptosis; KDM4A overexpression had the opposite effects, and significantly blocked the regulation of miR-526b on cell growth and invasion. Therefore, circ_SPECC1 can enhance miR-526b inhibitory effect on downstream KDM4A/YAP1 pathway by adsorbing it, thus inhibiting GC cell growth and invasion. These findings enrich the mechanism of circRNAs in GC and will provide more new targets for the prevention and treatment of GC.

Silencing GOLPH3 gene expression reverses resistance to cisplatin in HT29 colon cancer cells via multiple signaling pathways.

Golgi phosphorylated protein (GOLPH)3 is overexpressed in colorectal cancer tissues and promotes the proliferation of colon cancer cells. A previous study by the authors demonstrated that GOLPH3 was associated with poor prognosis in colorectal cancer. However, the association between GOLPH3 gene overexpression and resistance to platinum-based drugs in colon cancer remains unknown. In the present study, the association between GOLPH3 overexpression and resistance of HT29 colon cancer cells to cisplatin and the mechanism underlying the development of chemoresistance were investigated. HT29 cells were divided into five groups. The expression of GOLPH3 mRNA was measured in the control and siRNA transfection groups. Reverse transcription-quantitative polymerase chain reaction analysis, cell proliferation, colony formation assay, tumor sphere formation and apoptosis (Annexin V) assays, western blotting and a nude mouse tumorigenicity assay were performed. HT29 cells were resistant to 10 µM cisplatin treatment, whereas the expression of GOLPH3, P-glycoprotein, phosphorylated extracellular signal-regulated kinase (pERK)1/2 and ß-catenin protein was significantly upregulated compared with the control group. With cisplatin treatment, silencing GOLPH3 gene expression downregulated the expression of these proteins, reduced cell proliferation and tumorigenicity, induced apoptosis and reversed the resistance of HT29 cells to cisplatin. In addition, the change in pERK1/2 and ß-catenin expression demonstrated that the mechanism of GOLPH3 overexpression involved in cisplatin resistance was associated with activation of the mitogen-activated protein kinase/ERK and Wnt/ß­catenin signaling pathways in HT29 cells. The tumorigenicity experiment in nude mice also demonstrated that silencing GOLPH3 expression increased the sensitivity of HT29 cells to cisplatin in vivo. Therefore, overexpression of GOLPH3 may be involved in the resistance of HT29 colon cancer cells to cisplatin chemotherapy by activating multiple cell signaling pathways.

MicroRNA-145 exerts tumor-suppressive and chemo-resistance lowering effects by targeting CD44 in gastric cancer.

AIM: To determine the potential roles of CD4 and microRNA (miR)-145 in gastric cancer. METHODS: The levels of CD44 and miR-145 were determined in gastric cancer cells. Quantitative real-time polymerase chain reaction was used to measure to the level of CD44 mRNA. A luciferase reporter assay and western blotting were performed to examine the effect of miR-145 on CD44 expression. Tumor sphere and MTT assays were carried out to evaluate the self-renewal and chemo-resistance properties of gastric cancer cells. RESULTS: The expression of CD44 was greatly increased and miR-145 was decreased in gastric cancer cells that were highly enriched in cancer stem cells (CSCs). The results demonstrated that miR-145 regulated CD44 by targeting directly the CD44 3'-untranslated region (3'-UTR). In gastric cancer cells, overexpression of miR-145 repressed the activity of the CD44 3'-UTR, and disruption of miR-145/CD44 3'-UTR interactions abrogated the silencing effects. In addition, miR-145 inhibition stimulated CD44 3'-UTR activity and disruption of miR-145/CD44 3'-UTR interactions abrogated this stimulatory effect. Enforced CD44 expression greatly increased tumor sphere formation and chemo-resistance in gastric cancer cells. Furthermore, the inhibition of CSCs and the chemo-sensitivity of gastric cancer cells treated with miR-145 were significantly abrogated by overexpression of CD44. CONCLUSION: miR-145 targeting of CD44 plays critical roles in the regulation of tumor growth and chemo-resistance in gastric cancer.

[Relationship between the expression level of miR-29c and biological behavior of gastric cancer].

OBJECTIVE: To study the function and clinicopathological significance of RNA-29c (miR-29c) in the carcinogenesis and development of gastric cancer. METHODS: MicroRNA microarray was applied to assess the miRNAs expression profile of gastric cancer. Quantitative real-time PCR was used to detect the expression of miR-29c in 64 cases of gastric cancer tissues and corresponding normal gastric epithelium, as well as cell lines GES-1, BGC-823 and SGC-7901 cells. MTT assay and flow cytometry were applied to detect the effects of forced expression of miR-29c in gastric cancer BGC-823 cells including cell proliferation, apoptosis, cell cycle and drug sensitivity. Quantitative real-time PCR, Western blot and luciferase reporter assay were used to explore the targeted relationship between miR-29c and myeloid cell leukemia-1 (Mcl-1). RESULTS: Compared with normal gastric epithelium, seven microRNAs (miR-374b*, miRPlus-E1212, miR-338-5p, miR-297, miR-21, miR-135b, miR-18a) were significantly up-regulated more than 2-folds, and nine microRNAs (miR-29b-2*, miR-1260, miRPlus-E1241, miR-S1-5p, miR-148a, miR-29c, miR-647, miR-196b*, ebv-miR-BART5) were significantly down-reguated in gastric cancer tissues. The average expression level of miR-29c in gastric cancer tissues was 0.70 ± 0.34 and in corresponding normal epithelium was 1.00 ± 0.06 (P < 0.05). miR-29c expression was related to tumor size, lymph node metastasis, clinical stage, Laurén classification, Borrmann classification and Ming classification (P < 0.05). The poorer differentiation degree of gastric cell lines, the lower was miR-29c expression level (P < 0.05). Overexpression of miR-29c in gastric cancer BGC-823 cells suppressed cell proliferation, stimulated cell apoptosis, induced cell cycle arrest in S phase and increased the chemotherapy sensitivity to drug docetaxel (all were P < 0.05). The average expression level of Mcl-1 mRNA in gastric cancer tissues was 3.47 ± 1.34 and corresponding epithelialium was 1.00 ± 0.20 (P < 0.05). The expression level of miR-29c was negatively related with that of Mcl-1 mRNA in gastric cancer tissues. miR-29c directly targeted to regulation of Mcl-1 expression. CONCLUSIONS: There are special miRNA expression profile in gastric cancer. The expression of miR-29c is closely related to biological behavior of human gastric cancer. miR-29c is involved in targeted regulation of Mcl-1, and may be one of mechanisms of the carcinogenesis of gastric cancer.

[Clinicopathological significance and function of miR-135b in the occurrence and development of gastric cancer].

OBJECTIVE: To explore the function and clinicopathological significance of miR-135b in the occurrence and development of gastric cancer. METHODS: Seventy-two pairs of fresh gastric cancer tissues and corresponding normal gastric epithelium were collected at our department from September 2007 to March 2011. Six of them were randomly selected and miRNA microarray was applied to study the miRNA expression profiles of gastric cancer. Quantitative real-time PCR was used to validate the reliability of microarray and detect miR-135b expression in the above clinical samples, as well as cell lines GES-1, BGC-823 and SGC-7901. The methods of cell transfection, thiazolyl blue tetrazolium bromide (MTT) and flow cytometry were used to study the impact of miR-135 on cell proliferation, cell cycle and apoptosis of gastric cancer cells. Real-time quantitative PCR and Western blot were used to explore the relationship between miR-135b and adenomatous polyposis coli (APC). RESULTS: Compared with normal gastric tissues, 7 miRNA were significantly up-regulated and 9 miRNA significantly down-regulated for over 2 folds in gastric cancer tissues (P < 0.05). The results of microarray were verified by quantitative real-time PCR. MiR-135b expression was up-regulated in most clinical samples compared with their corresponding epithelium (n = 66, 91.67%). The average expression level of miR-135b in gastric cancer tissues was significantly higher than normal epithelium (3.42 ± 2.62 vs 1.00 ± 0.07, P < 0.05). MiR-135b was related to Laurén classification, tumor differentiation, invasion and pathologic tumor-node-metastasis (pTNM) stage of gastric cancer (all P < 0.05). The worse differentiation degree of gastric cell lines, the higher miR-135b expression level (P < 0.05). MiR-135b promoted gastric cancer cell proliferation, inhibited its apoptosis and directly regulated the expression of APC in gastric cancer cell. CONCLUSIONS: Special miRNA expression profiles of gastric cancer are found. MiR-135b is closely correlated with the biological behavior of human gastric cancer. And its regulation of APC may be one of the pathogenic mechanisms of gastric cancer.