Tertiary Lymphoid Structures Gene Signature Predicts Prognosis and Immune Infiltration Analysis in Head and Neck Squamous Cell Carcinoma.

Objectives: This study aims to assess the prognostic implications of gene signature of the tertiary lymphoid structures (TLSs) in head and neck squamous cell carcinoma (HNSCC) and scrutinize the influence of TLS on immune infiltration. Methods: Patients with HNSCC from the Cancer Genome Atlas were categorized into high/low TLS signature groups based on the predetermined TLS signature threshold. The association of the TLS signature with the immune microenvironment, driver gene mutation status, and tumor mutational load was systematically analyzed. Validation was conducted using independent datasets (GSE41613 and GSE102349). Results: Patients with a high TLS signature score exhibited better prognosis compared to those with a low TLS signature score. The group with a high TLS signature score had significantly higher immune cell subpopulations compared to the group with a low TLS signature score. Moreover, the major immune cell subpopulations and immune circulation characteristics in the tumor immune microenvironment were positively correlated with the TLS signature. Mutational differences in driver genes were observed between the TLS signature high/low groups, primarily in the cell cycle and NRF2 signaling pathways. Patients with TP53 mutations and high TLS signature scores demonstrated a better prognosis compared to those with TP53 wild-type. In the independent cohort, the relationship between TLS signatures and patient prognosis and immune infiltration was also confirmed. Additionally, immune-related biological processes and signaling pathways were activated with elevated TLS signature. Conclusion: High TLS signature is a promising independent prognostic factor for HNSCC patients. Immunological analysis indicated a correlation between TLS and immune cell infiltration in HNSCC. These findings provide a theoretical basis for future applications of TLS signature in HNSCC prognosis and immunotherapy.

Rare Recurrent EWSR1-PLAGL1 Rearranged Intracranial Tumor With Biphasic Epithelioid Differentiation: One Case Report With Literature Review.

EWSR1-rearranged tumors encompass a rare and heterogeneous group of entities with features of the central nervous system (CNS) mesenchymal and primary glial/neuronal tumors. EWSR1-PLAGL1 gene fusion is a particularly rare form of rearrangement. We presented a recurrent intracranial EWSR1-PLAGL1 rearranged tumor and reviewed the relevant literature. In this case, histopathology and immunohistochemistry (IHC) were evaluated for both the primary and relapsed tumors. Fluorescence in situ hybridization (FISH) and next-generation sequencing (NGS) were performed for the relapsed tumor. We compared the morphology, IHC results and molecular features with the previously reported EWSR1-PLAGL1 rearranged CNS tumors. Our case exhibited a unique feature with a variable biphasic pattern of epithelioid differentiation, which differed from the two reported groups. The primary and relapsed tumors both expressed cytokeratin of the focal area with epithelioid differentiation. The recurrent tumor showed an increased proliferation index (average Ki-67 index of 15%) compared with the primary tumor (average Ki-67 index of 5%). NGS showed that TERT promoter mutation was the only molecular change besides EWSR1-PLAGL1 fusion. Our study provides further insight into intracranial tumors with EWSR1-PLAGL1 fusion, representing a distinct CNS tumor with no-reported histological and immunohistochemical features. Future studies, particularly for the biphasic differentiation and the role of TERT promoter mutation were needed to clarify this unusual chromosomal rearrangement in the CNS tumor.

p53 Missense Mutation is Associated with Immune Cell PD-L1 Expression in Triple-Negative Breast Cancer.

The programmed death ligand 1 (PD-L1) is a pivotal biomarker of immunotherapy in triple negative breast cancer (TNBC). TP53 is reported as a positive regulatory predictor of immune efficacy. The correlation of p53 expression or mutation and PD-L1 expression is explored. By immunohistochemistry, PD-L1 expression between p53 mutation (missense and nonsense) and wild type; p53 no-expression/loss vs. expression were compared. There was a significant association between p53 mutation, especially missense mutation with higher histological grade, and PD-L1 expression in immune cells (ICs). Both p53 missense mutation and PD-L1 expression may be potential targets for improving immunotherapy response in TNBC.

miR-638 Serves as a Biomarker of 5-Fluorouracil Sensitivity to Neoadjuvant Chemotherapy in Breast Cancer.

PURPOSE: Neoadjuvant chemotherapy (NAC) is widely used to treat breast cancer (BC). The prediction and evaluation of chemotherapy responses remains a significant challenge. METHODS: MicroRNAs (miRNAs) play a crucial role in cancer drug resistance. We used a miRNA microarray and identified that miR-638 is downregulated in chemoresistant cases. However, the exact role of miR-638 and the underlying mechanisms of chemoresistance remain unclear. Using real-time quantitative reverse transcription polymerase chain reaction, we found significant downregulation of miR-638 in chemoresistant patients compared with chemosensitive patients. To explore the function of miR-638, we overexpressed and inhibited miR-638 expression in MDA-MB-231 and MCF-7 cells by transfecting them with miR-638 mimics and miR-638 inhibitor, respectively. Cell proliferation and apoptosis were measured using MTS and flow cytometry, respectively. A minimal patient-derived xenograft (MiniPDX™) model was established to evaluate the chemosensitivity to different drugs. RESULTS: The results showed that cell proliferation decreased and cell apoptosis increased in cells transfected with the miR-638 mimic, and cell proliferation and apoptosis were reversed with transfection of miR-638 inhibitor compared with the control group. Among patients who received 5-fluorouracil (5-FU), miR-638 expression levels were lower in the chemoresistant group than in the chemosensitive group. The MiniPDX™ model showed that MDA-MB-231 cells overexpressing miR-638 were more susceptible to 5-FU treatment in vivo. CONCLUSION: We provided evidence of acquired resistance to 5-FU caused by miR-638 deficiency. Alterations in miR-638 may be used with 5-FU chemotherapy during NAC for BC.

Clinicopathological Characteristics and Molecular Phenotypes of Primary Hepatic Lymphoma.

Primary hepatic lymphoma (PHL) is a rare malignant tumor, occurring in 0.016% of non-Hodgkin's lymphoma (NHL). The common histological subtype is diffuse large B-cell lymphoma (DLBCL). Due to the rarity of tumor, clinicopathological characteristics and molecular phenotypes of PHL are limited. Seven patients with PHL (primary liver DLBCL) and 13 cases of liver involvement by DLBCL diagnosed between 2014 and 2021 in our hospital were included. The genetic features were also compared between the two groups by next-generation sequencing (NGS). Differential gene expression and pathway enrichment analysis were also performed. There were some discrepancies on presenting symptoms, pathological characteristics, laboratory data, and prognosis between PHL and DLBCL-liver groups. No same mutation was found between PHL and DLBCL-liver groups by NGS. Differential gene expression analysis discovered some up- and downregulated genes in PHL compared with the DLBCL-liver group. Upregulated genes were enriched in metabolic pathways, and downregulated genes were enriched in the HTLV-1 infection pathway. PHL is a distinct entity, with unique molecular features compared to liver involvement of systemic lymphoma. Kaplan-Meier analysis showed that the prognosis of the PHL group was better than that of the DLBCL-liver group. Understanding the clinicopathological and molecular features of PHL would help to direct clinical treatment.

Anaplastic lymphoma kinase fusion protein expression is associated with a favorable prognosis in resected invasive mucinous lung adenocarcinoma: A retrospective study from two Chinese tertiary hospitals.

Background: Invasive mucinous adenocarcinoma (IMA) is a distinct variant of lung adenocarcinoma, which typically has a worse survival. However, its pathogenesis is potentially associated with a high degree of molecular heterogeneity, which might determine its different prognosis. Methods: We retrospectively analyzed 2207 consecutive lung adenocarcinoma patients who underwent radical resection at Qilu Hospital of Shandong University and Shandong Provincial Hospital from 2013 to 2019. Anaplastic lymphoma kinase (ALK) fusion protein expression was routinely detected by immunohistochemistry. The clinicopathological characteristics and treatment outcomes of IMA patients were retrieved, and compared between ALK-positive and ALK-negative IMA patients as well as between pure IMA and mixed IMA patients. The last follow-up was on December 31, 2020, and the median follow-up was 42 months. Results: A total of 98 patients (4.4%) were diagnosed with IMA. ALK protein expression was positive in 24.5% of IMAs, which was significantly higher than that of non-IMA lung adenocarcinomas (4.7%, P < 0.001). ALK-positive and ALK-negative IMA, as well as pure IMA and mixed IMA, showed similar distribution in terms of patients' age, gender and smoking history, stage, and primary tumor location, except for a higher rate of lymph node metastasis in mixed IMA (22.0% vs. 46.2%, P = 0.012). Five cases (20.8%) of ALK-positive IMAs and 28 cases (40.6%) of ALK-negative IMAs experienced recurrence. Multivariable-adjusted Cox regression analysis demonstrated that ALK expression was a favorable prognostic factor for both disease-free survival (hazard ratio [HR]: 0.354; 95% confidence interval [CI]: 0.131-0.960; P = 0.041) and overall survival (HR: 0.138; 95% CI: 0.029-0.658; P = 0.013) in resected IMA. No difference in disease-free survival (HR: 0.524; 95% CI: 0.237-1.157; P = 0.110) and OS (HR: 0.553; 95% CI: 0.199-1.537; P = 0.256) was observed between pure IMA and mixed IMA. Conclusion: Invasive mucinous lung adenocarcinoma showed higher ALK protein expression, which was a favorable prognostic factor for survival in early resected patients.

Identification of miRNA Signature in Breast Cancer to Predict Neoadjuvant Chemotherapy Response.

Background: Chemotherapy failure causes high breast cancer recurrence and poor patient prognosis. Thus, we studied a cohort of novel biomarkers to predict chemotherapeutic response in breast cancer. In this study, miRNA expression profiling was performed on 10 breast cancer punctured specimens sensitive to chemotherapy (MP grade 4, 5) and 10 chemotherapy resistant (MP grade 1). Differentially expressed miRNAs were verified by qRT-PCR in 60 initial samples, 59 validated samples and 71 independent samples. A miRNA signature was generated using a Logistic regression model. A receiver operating characteristic (ROC) test was used to assess specificity and sensitivity of single miRNA and miRNA signature. Target genes regulated by miRNAs and their involved signaling pathways were analyzed using GO enrichment and KEGG software. MiRNAs expression were separately compared with ER, PR, HER2 immunohistochemical staining and different drugs. qRT-PCR showed that the high expression of miR-23a-3p, miR-200c-3p, miR-214-3p and the low expression of miR-451a and miR-638 were closely related to chemoresistance. According to the formula for calculating the drug resistance risk, patients in the high-risk group were more likely to develop chemotherapy resistance than the low-risk group. Bioinformatics analysis showed that 5 miRNAs and target genes are mainly involved in p53, ubiquitin-mediated proteolysis, mTOR, Wnt, cells skeletal protein regulation, cell adhesion and ErbB signaling pathways. miR-451a expression was associated with ER, HER-2 status and anthracyclines. A miRNA signature of chemotherapeutic response may be clinically valuable for improving current chemotherapy regimens of individual treatment for patients with breast cancer.

Elevated ZBTB7A expression in the tumor invasive front correlates with more tumor budding formation in gastric adenocarcinoma.

PURPOSE: Tumor budding (TB) is reported to predict nodal involvement and recurrence in multiple human malignancies. However, it is not clear how TB forms. The purpose of this study is to find markers related to TB formation in gastric cancer and to investigate the underlying mechanisms. METHODS: TB was scored on hematoxylin-eosin staining slides in 122 gastric cancer cases. Immunostaining score of CREB1, GAGE12I, CTNND1, KIF26B and ZBTB7A both at the invasive front and in the center of the tumor were assigned to each case. Spearman's correlation with the TB score was performed to find the TB-related markers. In vitro study and RNA-seq using gastric cancer cell lines were done to unveil the mechanisms. RESULTS: TB could predict lymph node metastasis and is negatively associated with overall survival of the patients. The expression of ZBTB7A in the invasive front, rather than the other four markers, was much higher than that in the tumor center and was positively correlated with TB score. ZBTB7A could enhance migration and invasion of gastric cancer cells in vitro. RNA-seq data followed by RT-qPCR and western blot verification demonstrated the activation of EGFR-MAPK-ERK and PI3K-AKT-mTOR pathways and increased expression of EMT related markers upon ZBTB7A over-expression. CONCLUSION: Higher ZBTB7A expression in the tumor margin may contribute to the dissociation of tumor cells from the tumor mass to form TB by initiating EMT via EGFR-MEK-ERK and PI3K-AKT-mTOR pathway.

Primary Thyroid NUT Carcinoma With High PD-L1 Expression and Novel Massive IGKV Gene Fusions: A Case Report With Treatment Implications and Literature Review.

BACKGROUND: Nuclear protein in testis (NUT) carcinoma (NC) is a rare and aggressive undifferentiated carcinoma that typically arises from midline supradiaphragmatic structures. It is uniquely driven by a NUT gene rearrangement on chromosome 15q14. Few thyroid NCs have been reported and there are no established treatment guidelines for NUT carcinoma. METHOD: Ultrasound-guided fine needle aspiration smear was performed for the preoperative diagnosis of thyroid lesions. Cytopathology, histology, and immunochemical staining all indicated NC. Fluorescence in situ hybridization (FISH), qRT-PCR, and next-generation sequencing (NGS) were used to analyze the genetic characteristics of NC. RESULTS: We describe a rare case of thyrogenic NC in a 38-year-old male with cytological, histological, immunohistochemical, and genetic features. Cytological smears and histopathological specimens showed typical features of NC. Immunohistochemistry confirmed strong immunoreactivity with NUT, EMA, P63, TTF-1, and c-myc. CK19 was positive exclusively in sudden keratosis. No immunoreactivity was found for neuroendocrine markers. FISH was applied to isolate the NUT gene on chromosome 15q14. The NGS results revealed a BRD4-NUT gene fusion, which was further confirmed by RT-qPCR. Structural variation (SV) of NUTM1 occurred in the exon region, and the mutation site was 15q14. Moreover, BRD4 single-nucleotide variation (SNV) occurs in the 3' UTR at mutation site 19p13.12. The PD-L1 combined predictive score was over 30%. The patient received chemotherapy, followed by programmed cell death 1 (PD-1) inhibition with camrelizumab, and died 10 months after surgery. CONCLUSION: Thyroid NC is an extremely rare and fatal malignant tumor. It is necessary to consider NC when squamous differentiation is observed cytologically or histologically. NGS is an effective tool for obtaining the final diagnosis and obtaining a better understanding of tumor pathogenesis. A large number of IGKV gene fusions in addition to the BRD4-NUT fusion may play a role in the pathogenesis and immunotherapy response of NC. Immunotherapy for NC remains to be explored due to the rarity of this aggressive malignancy.

High-Grade Serous Carcinoma Resulting From Rectal Endometriosis and Complicated With Ovarian Cancer.

Endometriosis is one of the most common benign gynecological diseases. It shows similar attributes to those of some fatal tumors if it is becomes malignant. These attributes include invasion, implantation, and recurrence. Epidemiological, clinicopathological, molecular biological, and genetic evidence suggest that malignancy of endometriosis, referred to as endometriosis-associated malignancy (EAM), is histologically closely related to endometriosis. Atypical endometriosis, which usually causes EAM, is considered a transitional condition from benign endometriosis to cancer. Approximately 80% of EAMs occur in the ovary and are known as endometriosis-associated ovarian cancer (EAOC). However, extragonadal endometriosis is not common, and no earlier study reported an association between malignant transformation of rectal endometriosis and high-grade serous cancer. We report a rare case of high-grade serous carcinoma resulting from rectal endometriosis and complicated with ovarian cancer. A 63-year-old Chinese woman was admitted with a complaint of abdominal distension. We diagnosed the patient with ovarian carcinoma and decided on elective cytoreductive surgery as treatment for the patient. During the surgery, we found a solid mass of diameter 12 cm in the anterior rectal wall containing sticky brown fluid. Postoperative histopathological examination revealed high-grade serous carcinoma resulting from rectal endometriosis and complicated with ovarian cancer. The patient postoperatively received 6 cycles of chemotherapy consisting of carboplatin and paclitaxel and was followed up for 1 year with no recurrence of the condition.

The value of detection of S100A8 and ASAH1 in predicting the chemotherapy response for breast cancer patients.

Chemotherapy plays an important role in the treatment of breast cancer. However, chemoresistance remains the main obstacle for effective treatment, leading to poor prognosis. This study aims to investigate the value of detection of S100A8 and ASAH1 in predicting the chemotherapy response. Miller and Payne grades were used to assess the chemotherapy response in breast cancers. The expression of S100A8 and ASAH1, as well as ER, PR, HER2 and Ki-67 were assessed by immunohistochemical staining in 120 cases of non-special type invasive ductal carcinoma (IDC-NOS). S100A8 expression was higher in chemosensitive breast cancers than chemoresistant ones. Moreover, S100A8 expression was significantly correlated with the molecular subtypes and histological grade, but not with patients' age, tumor size and lymph nodes status. However, there was no significant difference in ASAH1 expression between chemoresistant and chemosensitive group. We also found that higher ASAH1 expression was correlated with positive lymph nodes status, but not with age, tumor size, molecular subtypes and histological grade. S100A8 was valuable in predicting chemotherapy response in breast cancers. The expression of ASAH1 was associated significantly with lymph nodes metastasis, indicating that ASAH1 may serve as a biomarker to predict patients' lymph nodes status in breast cancers.

Prognostic Value of microRNA Signature in Patients with Gastric Cancers.

The occurrence of lymph node metastases (LNM) after endoscopic submucosal dissection (ESD) in patients with gastric cancer (GC) leads to poor prognosis. However, few biomarkers are available to predict LNM in GC patients. Thus, we measured expression of 6 cancer-related miRNAs using real-time RT-PCR in 102 GC samples that were randomized into a training set and a testing set (each, 51 cases). Using logistic regression, we identified 4-miRNA (miR-27b, miR-128, miR-100 and miR-214) signatures for predicting LNM in GC patients. Patients with high-risk scores for the 4-miRNA signature tended to have higher LNM than those with low-risk scores. Meanwhile, the ROC curve of the 4-miRNA signature was better for predicting LNM in GC patients. In addition, Cox regression analysis indicated that a 2-miRNA signature (miR-27b and miR-214) or a miR-214/N stage signature was predictive of survival for GC patients. This work describes a previously unrecognized 4-miRNA signature involved in LNM and a 2-miRNA signature or miR-214/N stage signature related to GC patients' survival.

Suppression of SPIN1-mediated PI3K-Akt pathway by miR-489 increases chemosensitivity in breast cancer.

Drug resistance is one of the major obstacles for improving the prognosis of breast cancer patients. Increasing evidence has linked the association of aberrantly expressed microRNAs (miRNAs) with tumour development and progression as well as chemoresistance. Despite recent advances, there is still little known about the potential role and mechanism of miRNAs in breast cancer chemoresistance. Here we describe that 16 miRNAs were found to be significantly down-regulated and 11 up-regulated in drug-resistant breast cancer tissues compared with drug-sensitive tissues, using a miRNA microarray. The results also showed miR-489 to be one of the most down-regulated miRNAs in drug-resistant tissues and cell lines, as confirmed by miRNA microarray screening and real-time quantitative PCR. A decrease in miR-489 expression was associated with chemoresistance as well as lymph node metastasis, increased tumour size, advanced pTNM stage and poor prognosis in breast cancer. Functional analysis revealed that miR-489 increased breast cancer chemosensitivity and inhibited cell proliferation, migration and invasion, both in vitro and in vivo. Furthermore, SPIN1, VAV3, BCL2 and AKT3 were found to be direct targets of miR-489. SPIN1 was significantly elevated in drug-resistant and metastatic breast cancer tissues and inversely correlated with miR-489 expression. High expression of SPIN1 was associated with higher histological grade, lymph node metastasis, advanced pTNM stage and positive progesterone receptor (PR) status. Increased SPIN1 expression enhanced cell migration and invasion, inhibited apoptosis and partially antagonized the effects of miR-489 in breast cancer. PIK3CA, AKT, CREB1 and BCL2 in the PI3K-Akt signalling pathway, demonstrated to be elevated in drug-resistant breast cancer tissues, were identified as downstream effectors of SPIN1. It was further found that either inhibition of SPIN1 or overexpression of miR-489 suppressed the PI3K-Akt signalling pathway. These data indicate that miR-489 could reverse the chemoresistance of breast cancer via the PI3K-Akt pathway by targeting SPIN1. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Diagnostic value of miRNA-96-5p/3p in dysplastic nodules and well-differentiated small hepatocellular carcinoma.

AIM: Hepatocarcinogenesis is a multistep process from cirrhosis through low-grade dysplastic nodule, high-grade dysplastic nodule to hepatocellular carcinoma. Differential diagnosis between high-grade dysplastic nodules and early hepatocellular carcinomas is particularly difficult. The present study aims to identify a novel biological marker for differential diagnosis of the two lesions. METHODS: The expression level of an miRNA pair, miRNA-96-5p and 3p, was assessed by reverse transcription polymerase chain reaction in hepatic tissues. RESULTS: We showed that mature miRNA-96-5p and passenger strand miRNA-96-3p were differentially expressed in multistep hepatocarcinogenesis. miRNA-96-5p was significantly upregulated from cirrhosis, dysplastic nodules to hepatocellular carcinoma. However, significance of determination of miRNA-96-5p expression level for differential diagnosis between high-grade dysplastic nodule and hepatocellular carcinoma is limited. In contrast, the expression of miRNA-96-3p was detectable in cirrhosis and dysplastic nodules. Also, it was completely undetectable in the majority of hepatocellular carcinomas (30/34, 88.2%). The sensitivity and specificity of miRNA-96-3p negative expression for differential diagnosis of hepatocellular carcinomas from high-grade dysplastic nodules were 88.2% and 84.2%, respectively. In addition, a more specific diagnosis could be carried out by combining miRNA-96-3p with glypican 3, with the specificity of 100%. CONCLUSION: These findings demonstrated that miRNA-96-3p is a helpful diagnostic biomarker in differential diagnosis between high-grade dysplastic nodules and well-differentiated small hepatocellular carcinomas, especially in combination with glypican 3.

MicroRNA-27b, microRNA-101 and microRNA-128 inhibit angiogenesis by down-regulating vascular endothelial growth factor C expression in gastric cancers.

Vascular Endothelial Growth Factor C (VEGF-C) has critical roles in angiogenesis in human cancers; however, the underlying mechanisms regulating VEGF-C expression remain largely unknown. In the present study, VEGF-C protein expression and the density of blood vessels or lymphatic vessels were determined by immunohistochemistry in 103 cases of gastric cancer tissues. Suppression of VEGF-C by miR-27b, miR-101 and miR-128 was investigated by luciferase assays, Western blot and ELISA. The miRNAs expression levels were detected in human gastric cancers by real-time quantitative PCR. Cell proliferation, migration and invasion assays were performed to assess the effect of miRNAs on gastric cancer cells and human umbilical vascular endothelial cells (HUVECs). Our data showed that high VEGF-C expression was significantly associated with increased tumor size, advanced TNM classification and clinical stage, higher microvessel density (MVD) and lymphatic density (LVD), as well as poor survival in patients with gastric cancer. Furthermore, VEGF-C was found to be a direct target gene of miR-27b, miR-101, and miR-128. The expression levels of the three miRNAs were inversely correlated with MVD. Overexpression of miR-27b, miR-101, or miR-128 suppressed migration, proliferation activity, and tube formation in HUVECs by repressing VEGF-C secretion in gastric cancer cells. We conclude that miR-27b, miR-101 and miR-128 inhibit angiogenesis by down-regulating VEGF-C expression in gastric cancers.

C/EBPα-induced miR-100 expression suppresses tumor metastasis and growth by targeting ZBTB7A in gastric cancer.

MicroRNAs have been reported to play key roles in various human cancers, including gastric cancer. However, understanding of the expression of miR-100 and its regulatory mechanisms in human gastric cancer remains elusive. In this study, we reveal that miR-100 is downregulated in gastric cancer samples and gastric cancer cell lines. Furthermore, lower miR-100 expression was found in primary gastric cancer samples with lymphatic metastasis compared to those without lymphatic metastasis. Overexpression of miR-100 suppressed tumor growth in vivo and inhibited gastric cancer invasion and metastasis in vitro and in vivo. Furthermore, we demonstrated that miR-100 reduced gastric cancer aggressiveness by directly targeting ZBTB7A. Knockdown of ZBTB7A by siRNA disrupted gastric cancer progression by impairing tumor invasion and metastasis. High expression of ZBTB7A was significantly correlated with poorer prognosis in gastric cancer patients. Our results also showed that the transcription factor CCAAT/enhancer-binding protein alpha (C/EBPα) could induce the expression of miR-100 by binding to the putative promoter region of miR-100. This study demonstrated that miR-100 could be induced by C/EBPα and may act as a tumor suppressor gene by inhibiting ZBTB7A.

Catenin-δ1, negatively regulated by miR-145, promotes tumour aggressiveness in gastric cancer.

Increasing evidence supports the association of catenin-δ1 (CTNND1, p120ctn) with tumour development and progression. However, the mechanism and clinical significance of CTNND1 deregulation in gastric cancer remain unknown. The expression level and cellular localization of CTNND1 were determined by immunohistochemistry in 126 human gastric cancer and 50 non-tumourous tissues. The cellular localization of CTNND1 and epithelial cadherin (E-cadherin) were detected by immunofluorescence. Cell proliferation, apoptosis, migration and invasion assays were performed to assess the effect of CTNND1 cDNA or CTNND1 siRNA transfection on gastric cancer cells. Luciferase assay, western blot analysis and in vivo assays were used to determine whether CTNND1 could be regulated by miR-145. The results demonstrate that the cytoplasmic localization of CTNND1 protein, rather than expression level, was indicative of higher clinical stage, positive lymph node metastasis and poorer prognosis in gastric cancers. CTNND1 could promote gastric cancer cell migration and invasion with little effect on cellular proliferation and apoptosis. CTNND1 was proved to be a direct target gene for miR-145. Besides suppressing cytoplasmic CTNND1 expression, miR-145 could recover the membranous localization of CTNND1 and E-cadherin. We conclude that cytoplasmic CTNND1 can serve as an independent prognostic factor for patients with gastric cancers. MiR-145 inhibits invasion of gastric cancer cells not only by down-regulating cytoplasmic CTNND1 expression but also by inducing the translocation of CTNND1 and E-cadherin from the cytoplasm to the cell membrane through down-regulating N-cadherin.

Deregulated expression of miR-145 in manifold human cancer cells.

MicroRNAs play important roles in the processes of tumor initiation and progression. The expression level of miR-145 in gastric, liver, and cervical cancers has been rarely investigated. Whether miR-145 may function as a common tumor suppressor in the generation of tumor phenotype needs to be clarified. miR-145 expression was determined by RT-qPCR in various human cancer tissues including those of gastric, liver, colon, and cervical cancers. Cancer cell lines were transfected with miR-145 precursor, anti-miR-145 inhibitor, or negative control, and cells' proliferation, migration, and invasion activities were analyzed. The gene target of miR-145 was confirmed by luciferase assay and Western blot. The miR-145 expression level was lower by 37.68-, 2.64-, 2.69- and 2.39-fold in gastric, liver, colon, and cervical cancer tissues, respectively, compared to corresponding nontumorous controls. Moreover, miR-145 levels were significantly downregulated in various cancer cell lines. We further demonstrated that miR-145 could suppress anchorage-independent growth and cell motility in both the liver cancer cell line Hep-G2 and the gastric cancer cell line MKN-45, and inhibited cell proliferation in a cell type-specific manner. Insulin receptor substrate-1 (IRS1) was identified as a target gene of miR-145, by which miR-145 was able to suppress cell proliferation. miR-145 suppresses cell proliferation, anchorage-independent growth, cell motility, and may serve as a tumor suppressor.

[Expression of microRNA-100 in human gastric cancer].

OBJECTIVE: To investigate the expression of microRNA-100 (miR-100) in human gastric cancer cells and its role of miR-100 in migration, invasion and proliferation in gastric cancer cell line SGC7901. METHODS: Total RNAs were extracted from formalin-fixed and paraffin-embedded tissue samples of SGC7901 cells, gastric cancer (50 cases), non-tumor (18 cases) and lymph nodes with metastases (18 cases). The expression of miR-100 was examined by reverse transcription (RT)-qPCR. Additionally, SGC7901 cells were transfected with Pre-miR-100 and negative control constructs, and then their ability of migration, invasion and proliferation in vitro was documented after 48 hours. RESULTS: RT-qPCR showed that although miR-100 expressed in all samples, compared to non-tumour tissues, the expression was lower both in SGC7901 cells and gastric cancer tissues (P = 0.0077, P < 0.01). SGC7901 cells and primary gastric cancer tissues with lymph nodes metastasis had lower miR-100 expression than those of without lymph node metastasis (P = 0.0361, P = 0.0356). The migration ability and invasion of SGC7901 cells transfeced with pre-miR-100 decreased as compared with control cells (P = 0.0025, P = 0.0028 respectively). However, miR-100 expression had no significant effects on the cell proliferation. CONCLUSIONS: Expression of miR-100 inhibits the migration and invasion of gastric cancer cells without significant alteration of proliferation. Therefore, miR-100 may play an inhibitory role in the progression of gastric carcinoma.

Restoration of chemosensitivity in cancer cells with MDR phenotype by deoxyribozyme, compared with ribozyme.

One of the main mechanisms for multidrug resistance (MDR) involves multidrug resistance gene 1 (MDR1) which encodes P-glycoprotein (Pgp). Pgp acts as a drug efflux pump and exports chemotherapeutic agents from cancer cells. Specific inhibition of Pgp expression by gene therapy is considered a well-respective strategy having less innate toxicities. At present, the investigation of DRz in reversal MDR is scarce. In the study, phosphorothioate DRz that targets to the translation initiation codon AUG was synthesized and transfected into breast cancer cells and leukemia cells with MDR phenotype. ASODN (antisense oligonucleotide) and ribozyme targets to the same region were also synthesized for comparison analysis. Alterations in MDR1 mRNA and Pgp were determined by RT-PCR, Northern blot, flow cytometry and Rh123 retention tests. Chemosensitivity of the treated cells was determined by MTT assay. The results showed that DRz could significantly suppress expression of MDR1 mRNA and inhibit synthesis of Pgp. The efflux activity of Pgp was inhibited accordingly. Chemosensitivity assay showed that a 21-fold reduction in drug resistance for Adriamycin and a 45-fold reduction in drug resistance for Vinblastine were found in the treated cells 36h after transfection. These data suggest that DRz targeted to the translation initiation codon AUG can reverse MDR phenotype in cancer cells and restore their chemosensitivity. Moreover, the reversal efficiency of DRz is better than that of ribozyme and ASODN targets to the same region of MDR1 mRNA.