Cancer Biomarkers

Growing evidence suggests that microRNA plays an essential role in the development and metastasis of many tumors, including gastric cancer (GC). Expression of microRNA-203 (miR-203) has been reported to decrease in GC. In addition, overexpression of miR-203 inhibits grow of GC cells in vitro and in vivo. However, whether miR-203 affects cell migration and invasion of GC remains unclear. This study aimed to reveal the role of miR-203 on migration and invasion of GC, and its potential mechanisms.

Synthetic pre-miR-203 (miR-203), anti-miR-203 and scrambled negative control RNAs was transfected into the gastric cancer SGC7901 cells to generate miR-203 or anti-miR-203-transfected stable clones. The roles of miR-203 on cell invasion and motility were then analyzed by Transwell migration assay and Wound healing assay in vitro. Using siRNA to targeting ERK1/2, Slug, and E-cadherin or Slug cDNA transfection (to increase Slug expression) to examine the miR-203 signaling pathway. We also examined the efficacies of miR-203 or anti-miR-203 on peritoneal metastasis of SGC7901 cells in the nude mouse model.

Overexpression of miR-203 inhibits SGC7901 cell invasion and motility, followed by decreased phospho-ERK1/2 (pERK1/2) and Slug expression, as well as increased E-cadherin expression. Re-expression of Slug in miR-203/SGC7901cells decreased E-cadherin expression and restored the invasive phenotypes. Targeting E-cadherin in miR-203/SGC7901cells also restored the invasive phenotypes. Inhibition of miR-203 promotes SGC7901 cell invasion and motility, followed by increased phospho-ERK1/2 (pERK1/2) and Slug expression, as well as decreased E-cadherin expression. Targeting ERK1/2 or Slug in anti-miR-203/SGC7901cells increased E-cadherin expression and reversed the invasive phenotypes. In addition, targeting ERK1/2 decreased Slug and increased the E-cadherin expression. Significantly, we found that miR-203 could exert marked inhibition of the peritoneal metastasis of SGC7901 in nude mice in vivo. Targeting miR-203 could exert marked promotion of the peritoneal metastasis of SGC7901 in nude mice in vivo.

miR-203/ERK1/2/Slug/E-cadherin signaling pathway plays an essential role on SGC7901 cell invasion and motility. miR-203 can be novel modalities to prevent peritoneal metastasis of invasive cancers such as gastric cancer.

Many researches aiming to explore the pathogenesis of lung cancer have extensively studied the molecular alteration in such disease.

In the present study we measured the blood E2F3 mRNA using real-time RT-PCR technique in order to evaluate its clinical significance in early diagnosis and monitoring of lung cancer.

This case-control study included 50 lung cancer patients, 20 patients with benign lung diseases and 20 healthy controls. Relative quantification of blood E2F3 mRNA was done by real-time RT-PCR.

Blood E2F3 mRNA levels were significantly higher in lung cancer patients when compared to either patients with benign lung diseases or healthy subjects. This elevation was significant in those with metastatic lung cancer as compared to those with localized lung cancer. At a cutoff^{(2-Δ Δ CT)} 1.5, blood E2F3 mRNA was able to distinguish malignant from benign lung conditions with a diagnostic sensitivity of 100%; while at a cutoff^{(2-Δ Δ CT)} 5.3, blood E2F3 mRNA discriminated localized from metastatic lung cancer with a sensitivity of 93.6%.

Blood E2F3 mRNA is a sensitive diagnostic marker in lung cancer; moreover, it is a promising prognostic marker capable of efficiently discriminating early from late stages of the disease.

Aurora A kinase is frequently overexpressed in a variety of tumor types, including the prostate. However, the function of Aurora A in autophagy in prostate cancer has not been investigated. Here, we aimed to study the functioning mechanism and autophagy associated signaling pathways of Aurora A in prostate cancer.

To investigate the biological function of Aurora A, down-regulation of Aurora A was performed followed by functional testing assays. Immunohistochemistry was used to detect the expression of Aurora A in human prostate cancer specimens. CCK8, Transwell, flow cytometric analysis and measurement of tumor formation in nude mice were performed to test the effects of Aurora A down-regulation in vivo and in vitro. Signaling pathway analysis was performed by using Western blot. Autophagy activity was measured by monitoring the expression levels of LC3-II.

Aurora A overexpression was significantly higher in human prostate cancer specimens than in BPH. Furthermore, Aurora A knockdown inhibited the proliferation of prostate cancer cells by suppressing the Akt pathway, indicating that Akt is a novel Aurora A substrate in prostate cancer. Additionally, Aurora A down-regulation prompts autophagy in prostate cancer cells. Most importantly, Aurora A ablation almost fully abrogates tumorigenesis in nude mice, suggesting that Aurora A is a key oncogenic effector in prostate cancer.

Taken together, our data suggest that Aurora-A plays an important role in the suppression of autophagy by inhibiting the phosphorylation of Akt, which in turn prevents autophagy-induced apoptosis in prostate cancer.

Previous studies show that overexpression of stathmin involved in the malignant biological behavior of lung cancer. This investigation is to disclose the expression status of stathmin in non-small cell lung cancer (NSCLC) and its clinical value for the diagnosis and prognosis to lung cancer.

The expression of stathmin in cells and tissues of NSCLC was examined using immunohistochemistry (IHC), in-situ hybridization (ISH), and Western blot. The correlation between stathmin expression and survival of lung cancer patients was evaluated by a Kaplan-Meier method and the multiple regression analysis.

NSCLC tissues and cells showed an overexpression of stathmin compared with normal lung tissues and cells (p< 0.05). And the expression level of stathmin was significantly associated with lung adenocarcinoma (LAC) (p< 0.05), lymphatic invasion (p< 0.05) and advanced stages of NSCLC (p< 0.05). Moreover, overexpression of stathmin predicted a reduced survival (p<0.05).

Increased stathmin correlated with pathologic grade, lymphatic invasion, advanced stage and poor survival of NSCLC, which indicated that stathmin could serve as a potential biomarker of NSCLC.

Radiosensitivity by blocking the epidermal growth factor receptor and cyclooxygenase-2 pathways with erlotinib and celecoxib in A549 human lung cancer cell was investigated.

MTT assays were used to detect the antitumor effects of erlotinib and celecoxib in A549 cells. Colony formation assays were used to evaluate the antitumor effects. Flow cytometry analysis was used to assess the cell cycle and cell apoptosis, and western blotting analysis was performed to evaluate the expression of AKT and phosphorylated AKT.

Either erlotinib or celecoxib inhibited the A549 cell proliferation in a dose-dependent manner. Combining Erlotinib or celecoxib with radiation can suppress the cell colony formation and the Dq, D₀, SF₂ of the combining erlotinib or celecoxib with radiation was lower than in the combinations either erlotinib or celecoxib with radiation (t= 6.62, P< 0.05). The SER of radiation with celecoxib or erlotinib and celecoxib and erlotinib were 1.299, 1.503 and 2.217, respectively. The Flow cytometry analysis results showed that either celecoxib or erlotinib could induce G₀/G₁ arrest, and reduction of S phase cell proportion, especially when combinations erlotinib-celecoxib with radiation. Either celecoxib or erlotinib could enhance radiation-induced apoptosis, especially significant when combinations erlotinib-celecoxib with radiation. Moreover, radiation can promote the expression of pAKT, and the pAKT was remarkably lowest in the combinations erlotinib-celecoxib with radiation group (t= 4.89, P< 0.05).

Blocking both EGFR- and COX-2-related pathways could enhance the antitumor effect of radiation. The underlying mechanisms including the enhancement of apoptosis and radiation-induced G₀/G₁ arrest, possibly via inhibiting the PI3K/AKT signaling pathway.

Fibulin-4 (FBLN-4) is an extracellular glycoprotein that is upregulated in some cancer and is khown as prognostic marker in ovarian and cervical cancer. Breast cancer resistance protein (BCRP) is an ATP-binding cassette transporter that facilitates the efflux of various anticancer drugs from the cell and cause MDR phenotype in breast tumors. Many studies are available that indicat overexpression of BCRP gene in breast cancer.

In the present study we aimed to analyze the expression level of FBLN-4 and BCRP in Iranian breast cancer patients.

We collected 40 samples of breast cancer and normal tissue from Tehran Khatam-al-Anbia hospital. To analyze the gene expression by using Real Time RT-PCR FBLN-4 and BCRP gene expression level were measured and then the association of gene expression with breast cancer were determined.

Surprisingly the expression level ofFBLN-4 and BCRP genes were downregulated in tumor tissues compared to adjacent normal tissues. Comparison of the gene expression and clinico-pathology reports indicate FBLN-4 gene expression was associated with breast cancer histological grade. We found no correlation between the expressions of BCRP gene with any clinico-pathological characters.

Interestingly and in contrast with our expectation, we found that the expression level ofFBLN-4 and BCRP were downregulated in tumor compared to adjacent normal tissues.FBLN-4 was associated with grade histology and therefore can be considered as a potential prognostic biomarker.

The long non-coding RNAs (lncRNAs) are emerging as important regulators in cancer progression. Clear cell renal cell carcinoma(ccRCC) is one of the most common urological cancers with poor prognosis. In this study, we examined the functional role of the lncRNA, nuclear enriched abundant transcript 1 (NEAT1) in ccRCC progression.

We performed quantitative real time PCR and western blotting assays to measure mRNA and protein expression levels, respectively. CCK-8 assay, cell invasion and migration assays were used to determine the cell proliferative, cell invasive and migratory ability. Flow cytometric analysis was performed to examine cell apoptosis.

The expression levels of NEAT1 was up-regulated in ccRCC tissues and up-regulation of NETA1 was positively correlated with tumor size, higher Fuhrman grade, and lymph node metastasis, and also predicts worse 5-year survival rate of patients with ccRCC. NEAT1 knock-down by NEAT siRNAs transfection suppressed cell proliferation and induced cell apoptosis in ccRCC cell lines. In addition, NEAT1 knock-down suppressed cell invasion and migration and inhibited the mRNA and protein expression levels of epithelial-mesenchymal transition-related markers in ccRCC cell lines.

In conclusion, NEAT1 may be an important mediator in the regulation of ccRCC progression and predicts the poor prognosis in patients with ccRCC.