Gui Hu

miR-133b regulates the MET proto-oncogene and inhibits the growth of colorectal cancer cells in vitro and in vivo.

Colorectal cancer (CRC) is one of the leading causes of cancer-related mortality worldwide. MicroRNAs (miRs) are single-stranded, noncoding RNAs that are important in many biological processes. Although the oncogenic and tumor-suppressive functions of several miRs have been characterized, their precise biological roles remain largely unexplored. In the present study, the role of miR-133b was identified in the regulation of CRC cell proliferation and apoptosis. miR-133b expression was shown to be greatly downregulated in human CRC cells compared to normal colon cells. Downregulation of miR-133b expression was also significant in six of eight human CRC tissues compared with adjacent normal tissues. In the CRC cell lines SW-620 and HT-29, ectopic expression of miR-133b potently affected tumor cell proliferation and apoptosis in vitro and in vivo by direct targeting of the receptor tyrosine kinase MET. Transfection of SW-620 and HT-29 cells with miR-133b significantly suppressed a luciferase-reporter containing the MET-3′-untranslated region. Taken together, these results provide evidence that miR-133b regulated tumor cell proliferation and apoptosis through modulation of the MET signaling pathway.

Combinational treatment with microRNA‑133b and cetuximab has increased inhibitory effects on the growth and invasion of colorectal cancer cells by regulating EGFR.

Colorectal cancer (CRC) is the third most common cancer with a very poor prognosis predominantly due to its high rate of tumor invasion and migration, and its resistance to anti‑epidermal growth factor receptor (EGFR) therapy. Although CRC has been widely studied, the underlying molecular mechanism remains to be elucidated. MicroRNA (miR)‑133b has been demonstrated to act as a tumor suppressor in several human cancer types by regulating EGFR. However, the detailed involvement of miR‑133b and EGFR in CRC cells remain to be elucidated. The present study used reverse transcription quantitative polymerase chain reaction and characterized the downregulation of the expression levels of miR‑133b in CRC tissues and cell lines. Cell functional assays demonstrated that restored expression of miR‑133b inhibited the growth and invasion of CRC cells. In addition, a luciferase reporter assay revealed that miR‑133b directly targeted EGFR and repressed its expression levels in CRC cells. Additionally, combination treatment with miR‑133b mimics and the monoclonal anti‑EGFR antibody, cetuximab, which is approved and frequently used for treating patients with CRC, exhibited improved inhibitory effects on the growth and invasion of CRC cells compared with treatment with either alone. Taken together, the present study characterized the role of the miR‑133b/EGFR interaction in CRC cells and this suggested the combinational therapy with cetuximab and miR‑133b was positive and may be a potential novel treatment for patients with CRC in the future.

Comprehensive analysis of differentially expressed profiles of lncRNAs and construction of miR-133b mediated ceRNA network in colorectal cancer

Background Growing evidence suggests that long non-coding RNAs (lncRNAs) play a key role in tumorigenesis. However, the mechanism remains largely unknown. Results Thousands of significantly dysregulated lncRNAs and mRNAs were identified by microarray. Furthermore, a miR-133b-meditated lncRNA-mRNA ceRNA network was revealed, a subset of which was validated in 14 paired CRC patient tumor/non-tumor samples. Gene set enrichment analysis (GSEA) results demonstrated that lncRNAs ENST00000520055 and ENST00000535511 shared KEGG pathways with miR-133b target genes. Materials and Methods We used microarrays to survey the lncRNA and mRNA expression profiles of colorectal cancer and para-cancer tissues. Gene Ontology (GO) and KEGG pathway enrichment analyses were performed to explore the functions of the significantly dysregulated genes. An innovate method was employed that combined analyses of two microarray data sets to construct a miR-133b-mediated lncRNA-mRNA competing endogenous RNAs (ceRNA) network. Quantitative RT-PCR analysis was used to validate part of this network. GSEA was used to predict the potential functions of these lncRNAs. Conclusions This study identifies and validates a new method to investigate the miR-133b-mediated lncRNA-mRNA ceRNA network and lays the foundation for future investigation into the role of lncRNAs in colorectal cancer.

Negative feedback between TAp63 and Mir-133b mediates colorectal cancer suppression

Background TAp63 is known as the most potent transcription activator and tumor suppressor. microRNAs (miRNAs) are increasingly recognized as essential components of the p63 pathway, mediating downstream post-transcriptional gene repression. The aim of present study was to investigate a negative feedback loop between TAp63 and miR-133b. Results Overexpression of TAp63 inhibited HCT-116 cell proliferation, apoptosis and invasion via miR-133b. Accordingly, miR-133b inhibited TAp63 expression through RhoA and its downstream pathways. Moreover, we demonstrated that TAp63/miR-133b could inhibit colorectal cancer proliferation and metastasis in vivo and vitro. Materials and Methods We evaluated the correlation between TAp63 and miR-133b in HCT-116 cells and investigated the roles of the TAp63/miR-133b feedback loop in cell proliferation, apoptosis and metastasis via MTT, flow cytometry, Transwell, and nude mouse xenograft experiments. The expression of TAp63, miR-133b, RhoA, α-tubulin and Akt was assessed via qRT-PCR, western blot and immunofluorescence analyses. miR-133b target genes were identified through luciferase reporter assays. Conclusions miR-133b plays an important role in the anti-tumor effects of TAp63 in colorectal cancer. miR-133b may represent a tiemolecule between TAp63 and RhoA, forming a TAp63/miR-133b/RhoA negative feedback loop, which could significantly inhibit proliferation, apoptosis and metastasis.

MicroRNA‑133b inhibits connective tissue growth factor in colorectal cancer and correlates with the clinical stage of the disease.

Accumulating evidence indicates that dysregulation of microRNA‑133b (miR‑133b) is an important step in the development of certain types of human cancer and contributes to tumorigenesis. Altered expression of miR‑133b has been reported in colon carcinoma, but its association with clinical stage in colorectal cancer (CRC) has remained elusive. Connective tissue growth factor (CTGF), a potentially promising candidate gene for interaction with miR‑133b, was screened using microarray analysis. The expression of miR‑133b and CTGF was evaluated using reverse transcription‑quantitative polymerase chain reaction and western blot analysis. The regulatory effects of miR‑133b on CTGF were evaluated using a dual‑luciferase reporter assay. CTGF was identified as a functional target of miR‑133b. The results demonstrated low expression of miR‑133b in CRC specimens with poor cell differentiation (P=0.011), lymph node metastasis (P=0.037) and advanced clinical stages (stage III or IV vs. I or II; P=0.036). Furthermore, there was a significant association between a high level of expression of CTGF mRNA and an advanced clinical stage (stage III or IV vs. I or II; P=0.015) and lymph node metastasis (P=0.034). CTGF expression was negatively regulated by miR‑133b in the human colorectum, suggesting that miR‑133b and CTGF may be candidate therapeutic targets in colorectal cancer.

CTGF enhances resistance to 5-FU-mediating cell apoptosis through FAK/MEK/ERK signal pathway in colorectal cancer

Colorectal cancer (CRC) is one of the most commonly diagnosed cancers among both males and females; the chemotherapy drug 5-fluorouracil (5-FU) is one of a doctors’ first lines of defense against CRC. However, therapeutic failures are common because of the emergence of drug resistance. Connective tissue growth factor (CTGF) is a secreted protein that binds to integrins, and regulates the invasiveness and metastasis of certain carcinoma cells. Here, we found that CTGF was upregulated in drug-resistant phenotype of human CRC cells. Overexpression of CTGF enhanced the resistance to 5-FU-induced cell apoptosis. Moreover, downregulating the expression of CTGF promoted the curative effect of chemotherapy and blocked the cell cycle in the G1 phase. We also found that CTGF facilitated resistance to 5-FU-induced apoptosis by increasing the expression of B-cell lymphoma-extra large (Bcl-xL) and survivin. Then we pharmacologically blocked MEK/ERK signal pathway and assessed 5-FU response by MTT assays. Our current results indicate that the expression of phosphorylated forms of MEK/ERK increased in high CTGF expression cells and MEK inhibited increases in 5-FU-mediated apoptosis of resistant CRC cells. Therefore, our data suggest that MEK/ERK signaling contributes to 5-FU resistance through upstream of CTGF, and supports CRC cell growth. Comprehending the molecular mechanism underlying 5-FU resistance may ultimately aid the fight against CRC.

Simultaneous giant mucinous cystadenoma of the appendix and intestinal schistosomiasis: ‘case report and brief review’

Both mucinous cystadenoma of the appendix and intestinal schistosomiasis are rare lesions. We report a rare case of simultaneous giant mucinous cystadenoma of the appendix and intestinal schistosomiasis. A 64-year-old man from China presented with a one-year history of pain in the right lower quadrant of the abdomen. There were no other pertinent historical findings, other than schistosomiasis. Imaging showed a large, tubular, mesenteric cystic structure extending downwards from the inferior wall of the cecum. Right hemicolectomy was performed for the appendiceal tumor. The final pathological diagnosis was mucinous cystadenoma with calcified Schistosome eggs within the mucosa and submucosa of the appendix, small intestine, colon, and lymph nodes. We deduced that the pathogenesis of appendiceal mucinous cystadenoma in our case was Schistosome eggs causing luminal obstruction, finally resulting in intraluminal accumulation of mucoid material. Postoperatively, the patient recovered well.

Biological functions and clinical significance of the newly identified long non‑coding RNA RP1‑85F18.6 in colorectal cancer

The biological functions of long non-coding RNAs (lncRNAs) in cancer have not been fully elucidated. The present study demonstrated that the expression of a newly identified lncRNA, RP1-85F18.6, was upregulated in colorectal cancer (CRC) tissues and cell lines. Knockdown of lncRNA RP1-85F18.6 served a key role in tumor inhibition, reduced cell proliferation and invasion, disrupted the cell cycle, and increased apoptosis and pyroptosis of CRC cells. Conversely, overexpression of lncRNA RP1-85F18.6 exerted the opposite effects. Furthermore, silencing lncRNA RP1-85F18.6 decreased ΔNp63 expression at both the mRNA and protein levels. Furthermore, co-transfection with ΔNp63 siRNA and lncRNA RP1-85F18.6-expressing vector attenuated the tumor-promoting effects of lncRNA RP1-85F18.6 overexpression. The expression levels of lncRNA RP1-85F18.6, ΔNp63 and gasdermin D (GSDMD) were revealed to be associated with lymph node and distant metastases in patients with CRC, and therefore may serve as predictors in CRC. The findings of the present study suggested that lncRNA RP1-85F18.6 may trigger CRC cell proliferation, invasion and cell cycle disruption, and suppress apoptosis and pyroptosis of CRC cells through regulating ΔNp63 expression. Therefore, lncRNA RP1-85F18.6 and ΔNp63 may be considered unfavorable biomarkers, whereas GSDMD may be a favorable biomarker in CRC; these markers may prove valuable in the future diagnosis and prognosis of CRC.

POFUT1 promotes colorectal cancer development through the activation of Notch1 signaling

Copy number variations (CNVs) are key drivers of colorectal cancer (CRC). Our previous studies revealed that protein O-fucosyltransferase 1 (POFUT1) overexpression is driven by CNVs during CRC development. The potential role and underlying mechanisms of POFUT1 in CRC were not investigated. In this study, we analyzed the expression of POFUT1 in CRC from cosmic and TCGA databases and confirmed that POFUT1 is highly expressed in CRC. We used well characterized CRC cell lines, including SW620 and HCT116 to establish a model POFUT1 knockdown cell line. Using these cells, we investigated the role of POFUT1 in CRC. Our data revealed that silencing POFUT1 in CRC cells inhibits cell proliferation, decreases cell invasion and migration, arrests cell cycle progression, and stimulates CRC cell apoptosis in vitro. We further demonstrate that POFUT1 silencing dramatically suppresses CRC tumor growth and transplantation in vivo. We additionally reveal new mechanistic insights into the role of POFUT1 during CRC, through demonstrating that POFUT1 silencing inhibits Notch1 signaling. Taken together, our findings demonstrate that POFUT1 is a tumor activating gene during CRC development, which positively regulates CRC tumor progression through activating Notch1.

Profiling of differentially expressed genes in adipose tissues of multiple symmetric lipomatosis

Multiple symmetric lipomatosis (MSL) is a rare disorder characterized by aberrant multiple and symmetric subcutaneous adipose tissue accumulation in the face, neck, shoulders, back, chest and abdomen, severely affecting the quality of life of patients. At present, precise MSL etiology and pathogenesis remain to be elucidated. The present study first utilized a digital gene expression technique with a next-generation sequencing platform to profile differentially expressed genes in three cases of MSL vs. normal control tissue. cDNA libraries from these tissue specimens were constructed and DNA sequenced for identification of differentially expressed genes, which underwent bioinformatic analysis using the Gene Ontology (GO) enrichment, Kyoto Encyclopedia of Genes and Genomes (KEGG) and protein-protein interaction (PPI) network analyses. As a result, a total of 859 differentially expressed genes were identified, including 308 upregulated genes (C19orf80, Apelin, C21orf33, FAM166B and HSD11B2 were mostly upregulated 6.984-, 4.670-, 4.412-, 3.693- and 3.561-fold, respectively) and 551 downregulated genes [FosB proto-oncogene, AP-1 transcription factor subunit (FOSB), selectin (SEL) E, RAR related orphan receptor (ROR) B, salt inducible kinase (SIK)1 and epidermal growth factor-like protein (EGFL)6 were mostly downregulated −9.845, −8.243, −8.123, −7.702 and −7.664 fold, respectively). The GO functional enrichment analysis demonstrated these differentially expressed genes were predominantly involved in biological processes and cellular components, while the KEGG pathway enrichment analysis demonstrated that ribosome, non-alcoholic fatty liver disease, human T-lymphotropic virus type 1 (HTLV-I) infection and Alzheimers disease pathways were altered in MSL. The PPI network data demonstrated ubiquitin C (UBC), translocator protein (TSPO), Jun Proto-Oncogene, AP-1 Transcription Factor (JUN) and FOS were among these differentially expressed genes that participated in regulation of adipocyte differentiation, although no previous study has linked them to MSL. In conclusion, the present study profiled differentially expressed genes in MSL and identified gene pathways that may be associated with MSL development and progression.