MicroRNA-3690 promotes cell proliferation and cell cycle progression by altering DKK3 expression in human thyroid cancer.

An increasing amount of evidence has demonstrated the importance of microRNAs (miRNAs/miRs) in the tumorigenesis of malignant types of cancer, and data retrieved from The Cancer Genome Atlas database revealed that miR-3690 was upregulated in thyroid cancer (TC). The present study focused on the biological function and mechanism of miR-3690 in TC, demonstrating that miR-3690 expression was significantly elevated in TC cells and clinical tissues. Functional studies indicated that miR-3690 acted as an oncogene in TC by promoting cell proliferation, colony formation and cell cycle progression in association with the increased expression of cyclin E and c-myc. Mechanistically, prediction software indicated that Dickkopf-related protein 3 (DKK3) was a target of miR-3690, which was confirmed by the results of luciferase reporter assays and western blotting. DKK3 silencing abrogated the functions of miR-3690-in on TC cell proliferation. Collectively, the findings of the present study demonstrated that miR-3690 promoted TC cell proliferation and indicated miR-3690 as a potential biomarker and therapeutic target for TC.

Long non-coding RNA SPRY4-IT1 pormotes colorectal cancer metastasis by regulate epithelial-mesenchymal transition.

Colorectal cancer (CRC) remains one of the most common cancers worldwide. Increasing evidence indicates that SPRY4 intronic transcript 1 (SPRY4-IT1) regulate cell growth, differentiation, apoptosis, and cancer progression. However, the expression and function of SPRY4-IT1 in the progression of CRC remains largely unknown. Here, we reported that SPRY4-IT1 was upregulated in CRC. Increased SPRY4-IT1 expression in CRC was associated with larger tumor size and higher clinical stage. In vitro experiments revealed that SPRY4-IT1 knockdown significantly inhibited CRC cell proliferation by causing G1 arrest and promoting apoptosis, whereas SPRY4-IT1 overexpression promoted cell proliferation. Further functional assays indicated that SPRY4-IT1 overexpression significantly promoted cell migration and invasion by regulate the epithelial-mesenchymal transition (EMT). Taken together, our study demonstrates that SPRY4-IT1 could act as a functional oncogene in CRC, as well as a potential therapeutic target to inhibit CRC metastasis.

MiR-384 regulated IRS1 expression and suppressed cell proliferation of human hepatocellular carcinoma.

Acquired evidence indicated that microRNAs (miRNAs) played essential roles in cancer development, including hepatocellular carcinoma (HCC). Functions and mechanisms of miRNAs involved in HCC remain largely unknown. Here, we found that miR-384 was significantly downregulated in HCC cells and tissues by RT-PCR. Gain and loss of function studies revealed that miR-384 significantly suppressed HCC cell proliferation. Insulin receptor substrate 1(IRS1) was identified as a direct and functional target of miR-384. Moreover, miR-384 decreased IRS1 expression, subsequently downregulating cyclin D1 and upregulating p21 and p-Rb expression. In addition, promotion of cell proliferation caused by miR-384-in was counteracted by silencing IRS1 expression with siRNAs. Taken together, our data provided convincing evidence that miR-384 exerted suppressive effect on HCC cell proliferation through the direct inhibition of IRS1 expression, suggesting miR-384 may serve as a potential therapeutic target for HCC.

Activated protease receptor-2 induces GATA6 expression to promote survival in irradiated colon cancer cells.

BACKGROUND AND AIMS: The resistance to irradiation is common and a great drawback in the treatment of cancer with radiotherapy; the underlying mechanism is unclear. GATA binding protein 6 (GATA6) is associated with the pathogenesis of cancer. This study aims to investigate the role of GATA6 on compromising irradiation effect on HT55 and HT29 cells, 2 colorectal cancer cell lines. METHODS: Human colon cancer cell lines, HT55 and HT29 cells, were treated with irradiation in the culture. Apoptosis of HT55 and HT29 cells was determined by flow cytometry. The expression of PAR2 and GATA6 in HT55 and HT29 cells was analyzed by real time RT-PCR and Western blotting. The gene silence and gene over expression were employed to observe the effect of GATA6 on p53 expression in HT55 and HT29 cells. RESULTS: The results showed that HT55 and HT29 cells expressed protease-activated receptor-2 (PAR2). Irradiation induced 38.6% HT55 cell and 33.8% HT29 cell apoptosis, which reduced to 4.2% and 5.6%, respectively after activation of PAR2. Exposure to irradiation increased the expression of GATA6; the latter played a critical role in suppression of p53 expression in HT55 and HT29 cells. Inhibition of GATA6 significantly increased the effect of irradiation on HT55 and HT29 cells. CONCLUSIONS: Activation of PAR2 compromises the effect of irradiation on inducing colorectal cancer cell apoptosis, which can be prevented by inhibition of GATA6 expression.

Synergism from the combination of ulinastatin and curcumin offers greater inhibition against colorectal cancer liver metastases via modulating matrix metalloproteinase-9 and E-cadherin expression.

Liver metastasis is a major cause of mortality in colorectal cancer (CRC). The current study was to investigate the ability of ulinastatin (UTI) and curcumin (CUR) to inhibit CRC liver metastases via modulating matrix metalloproteinase-9 (MMP-9) and E-cadherin expression. Human CRC HCT-116 cells were treated with compounds individually and in combination in order to understand the effect on cell migration and invasion. The HCT-116 cell line was established to stably express luciferase and green fluorescent protein (GFP) by lentiviral transduction (HCT-116-Luc-GFP). We identified an anti-metastasis effect of UTI and CUR on a CRC liver metastasis mouse model. Tumor development and therapeutic responses were dynamically tracked by bioluminescence imaging. Expression of MMP-9 and E-cadherin in metastatic tumors was detected by immunohistochemical assay. Results of wound healing and cell invasion assays suggest that treatment with UTI, CUR, and UTI plus CUR, respectively, significantly inhibit HCT-116 cell migration and invasion. Furthermore, results of CRC hepatic metastasis on a nude mouse model showed that treatment with UTI, CUR alone, and a combination notably inhibited hepatic metastases from CRC and prolonged survival of tumor-bearing mice, especially in the UTI plus CUR group. These results suggest that the combination of UTI and CUR together may offer greater inhibition against metastasis of CRC.

Ulinastatin reduces cancer recurrence after resection of hepatic metastases from colon cancer by inhibiting MMP-9 activation via the antifibrinolytic pathway.

High recurrence of colon cancer liver metastasis is observed in patients after hepatic surgery, and the cause is believed to be mostly due to the growth of residual microscopic metastatic lesions within the residual liver. Therefore, triggering the progression of occult metastatic foci may be a novel strategy for improving survival from colon cancer liver metastases. In the present study, we identified an anti-recurrence effect of ulinastatin on colon cancer liver metastasis in mice after hepatectomy. Transwell cell invasion assays demonstrated that ulinastatin significantly inhibited the in vitro invasive ability of colon cancer HCT116 cells. Moreover, gelatin zymography and ELISA analysis showed that MMP-9 activity and plasmin activity of colon cancer HCT116 cells were inhibited by ulinastatin, respectively. Furthermore, in vivo BALB/C nu/nu mice model indicated that ulinastatin effectively reduced recurrence after resection of hepatic metastases from colon cancer. The optimum timing for ulinastatin administration was one week after hepatectomy. Taken together, our findings point to the potential of ulinastatin as an effective approach in controlling recurrence of hepatic metastases from colon cancer after hepatectomy via its anti-plasmin activity.

[Experimental study of NK4 gene targeted therapy mediated by human telomerase reverse transcriptase promoter for colon cancer].

OBJECTIVE: To investigate anti-tumor effect of the recombined adenovirus encoding NK4 gene regulated by human telomerase reverse transcriptase (HTERT) promoter (Ad HTERTp-NK4) on human colon cancer. METHODS: Colon cell line HCT116 was infected with Ad HTERTp-NK4. NK4 expression was determined by RT-PCR and Western blot. The cell-growth inhibition rate and the invasive capacity of cells were evaluated by MTT method and reconstituted basement membrane invasion assay. The model of subcutaneous tumor was generated by injection of HCT116 cells into the dorsum of nude mice. Ad HTERTp-NK4 was injected around the tumor tissues, and tumor growth was observed. RESULTS: NK4 gene was highly expressed in infected HCT116 cells. The cell growth inhibition rate and the invasive inhibition rate in Ad HTERTp-NK4 cells were 47.14% and 40.63% respectively, which were significantly higher than those in the control cells (2.75% and 2.31%, P<0.05). Tumor growth was significantly inhibited in mice injected with Ad HTERTp-NK4, and the tumor growth inhibition rate was 47.3%, which was significantly higher than that in the controls (4.6%, P<0.05). CONCLUSION: Ad HTERTp-NK4 can inhibit tumor growth and decrease the invasive capacity of tumor cells, which makes it an ideal candidate for new gene therapy for colon carcinoma.

[Influence of liver regeneration after partial hepatectomy on the development of liver metastasis of colon cancer in rats].

OBJECTIVE: To investigate the stimulated effect of liver regeneration on colon cancer cells in remnant liver in rats. METHODS: Rat models with liver metastases or retro-peritoneal metastases of colon cancer were established: animals underwent 37% or 70% liver resection and were compared with a sham laparotomy (15, 25, 15 cases, respectively). Metastases were performed two weeks before resection. Rats were killed 3 weeks after the resection. Total body weight, liver and tumor weights were recorded. The human colon adenocarcinoma cell line Lovo was cultured in the presence of portal serum withdrawn 24 hours and 14 days after partial hepatectomy (PH). DNA synthesis was assessed by flow cytometry analysis for 5-Bromodeoxyuridine (5-BrdU) incorporation. RESULTS: The tumor growth was accelerated in the remnant liver in 70% PH group, but the tumors in 37% PH group and retro-peritoneal site were not influenced by PH. Compared with the control group, after cultured 72 hours with portal serum withdrawn 24 h after PH, a higher 5-BrdU incorporation was found in the Lovo cell lines (P < 0.05), and it reached the peak after 120 hours of culture (P < 0.05). No difference was found between the groups when cultured with the portal serum withdrawn 14 d after PH (P > 0.05). CONCLUSIONS: PH may accelerate the growth of residual microscopic tumor in the liver which contributes to local recurrence. It has no systemic effect and effects on the cancer cell lines in extrahepatic sites. The excision extension is related to the stimulating effects on the cancer cell line, and subtotal hepatectomy is presumably a major determinant.

Decreased fragile histidine triad expression in colorectal cancer and its association with apoptosis inhibition.

AIM: To detect the expression of fragile histidine triad (FHIT) in normal colorectal tissue, colorectal adenoma and colorectal cancer (CRC) tissue, and to analyze its relationship with the clinicopathological features of CRC, and apoptosis-associated proteins (Bcl-2, Bax, survivin) and apoptosis in colorectal cancer. METHODS: FHIT mRNA analysis was performed by nested reverse transcription-polymerase chain reaction (RT-PCR) assay. Tissue microarray (TMA) was established to detect the expression of FHIT, Bcl-2, Bax and survivin genes in 80 CRC tissue specimens, 16 colorectal adenoma tissue specimens and 16 hemorrhoid (PPH) tissue specimens during the same period of time as the control. Citrate-microwave-SP was used as immunohistochemical method. The relationship between clinicopathological factors, such as differentiation grades and 5-year survival rate was observed. TUNEL assay was used to detect the apoptosis index in 80 CRC tissue specimens. RESULTS: Ten out of 26 (38.5%) CRC tissue specimens expressed aberrant FHIT transcripts, none of the aberrant FHIT transcripts was observed in the matched normal tissue and colorectal adenoma tissue by nested RT-PCR assay. The positive rate of FHIT gene expression in normal colorectal tissue, colorectal adenoma and carcinoma tissue was 93.75%, 68.75% and 46.25%, respectively. Clinicopathological analysis of patients showed that the decreased FHIT gene expression was not associated with age, sex, serum CEA levels, tumor site and size, histological classification. However, the expression of FHIT was correlated with differentiation grades, pathological stages, lymph node metastases and 5-year survival rate after operation. The positive rate of apoptosis-associated proteins (Bax, Bcl-2 and survivin) in CRC tissue was 72.50%, 51.25% and 77.50%, respectively. The expression of these apoptosis-associated proteins in CRC tissue was correlated with the expression of FHIT. The mean apoptosis index in FHIT negative tumors was significantly lower than that in FHIT positive tumors (5.41 +/- 0.23 vs 0.56 +/- 0.10, P < 0.01). CONCLUSION: The FHIT gene plays an important role in the regulation of apoptosis and decreased FHIT expression plays a key role in the initiation and progression of colorectal carcinoma.