Long non-coding RNA RP11-468E2.5 curtails colorectal cancer cell proliferation and stimulates apoptosis via the JAK/STAT signaling pathway by targeting STAT5 and STAT6.

BACKGROUND: Long non-coding RNAs (lncRNAs) are tumor-associated biological molecules and have been found to be implicated in the progression of colorectal cancer (CRC). This study aims to examine the effects of lncRNA RP11-468E2.5 and its target genes (STAT5 and STAT6) on the biological activities of CRC cells via the Janus kinase-signal transducer and activator of transcription (JAK/STAT) signaling pathway. METHODS: We initially screened the GEO database for differentially expressed lncRNAs related to CRC and then made a prediction of the implicated target genes. Then we collected CRC tissues and adjacent normal tissues from 169 CRC patients. Human CRC HCT116 and SW480 cells were treated with small interference RNA (siRNA) against RP11-468E2.5, AG490 (an inhibitor of the JAK/STAT signaling pathway), or both in combination. Next, we measured the effects of RP11-468E2.5 treatment on cellular activities such as cell viability, cycle distribution and cell apoptosis, and studied interactions among RP11-468E2.5, STAT5/STAT6, and the JAK/STAT signaling pathway. Finally, an in vivo tumor formation assay was performed to observe the effect of RP11-468E2.5 on tumor growth. RESULTS: The CRC-related gene microarray data showed low expression of RP11-468E2.5 in CRC surgical specimens. However, RP11-468E2.5 was confirmed to target STAT5 and STAT6, which participate in the JAK/STAT signaling pathway. CRC tissues showed lower expression of RP11-468E2.5, higher expression of STAT5, STAT6 and of the cell cycle marker Cyclin D1 (CCND1), compared to the findings in adjacent normal tissues. The treatment of siRNA against RP11-468E2.5 increased expression of JAK2, STAT3, STAT5, STAT6, CCND1 and Bcl-2 along with the extent of STAT3, STAT5 and STAT6 phosphorylation, while lowering expression of P21 and P27. Treatment with AG490 exhibited approximately opposite effects, whereas siRNA against RP11-468E2.5 treatment stimulated CRC cell proliferation and reduced cell apoptosis, while promoting cell cycle entry; AG490 treatment reversed these results. CONCLUSIONS: Altogether, we conclude that up-regulation of RP11-468E2.5 inhibits the JAK/STAT signaling pathway by targeting STAT5 and STAT6, thereby suppressing cell proliferation and promoting cell apoptosis in CRC.

Identification of differentially expressed genes associated with the enhancement of X-ray susceptibility by RITA in a hypopharyngeal squamous cell carcinoma cell line (FaDu).

BACKGROUND: Next generation sequencing and bio-informatic analyses were conducted to investigate the mechanism of reactivation of p53 and induction of tumor cell apoptosis (RITA)-enhancing X-ray susceptibility in FaDu cells. MATERIALS AND METHODS: The cDNA was isolated from FaDu cells treated with 0 X-ray, 8 Gy X-ray, or 8 Gy X-ray + RITA. Then, cDNA libraries were created and sequenced using next generation sequencing, and each assay was repeated twice. Subsequently, differentially expressed genes (DEGs) were identified using Cuffdiff in Cufflinks and their functions were predicted by pathway enrichment analyses. Genes that were constantly up- or down-regulated in 8 Gy X-ray-treated FaDu cells and 8 Gy X-ray + RITA-treated FaDu cells were obtained as RITA genes. Afterward, the protein-protein interaction (PPI) relationships were obtained from the STRING database and a PPI network was constructed using Cytoscape. Furthermore, ClueGO was used for pathway enrichment analysis of genes in the PPI network. RESULTS: Total 2,040 and 297 DEGs were identified in FaDu cells treated with 8 Gy X-ray or 8 Gy X-ray + RITA, respectively. PARP3 and NEIL1 were enriched in base excision repair, and CDK1 was enriched in p53 signaling pathway. RFC2 and EZH2 were identified as RITA genes. In the PPI network, many interaction relationships were identified (e.g., RFC2-CDK1, EZH2-CDK1 and PARP3-EZH2). ClueGO analysis showed that RFC2 and EZH2 were related to cell cycle. CONCLUSIONS: RFC2, EZH2, CDK1, PARP3 and NEIL1 may be associated, and together enhance the susceptibility of FaDu cells treated with RITA to the deleterious effects of X-ray.

RhNRG-1ß Protects the Myocardium against Irradiation-Induced Damage via the ErbB2-ERK-SIRT1 Signaling Pathway.

Radiation-induced heart disease (RIHD), which is a serious side effect of the radiotherapy applied for various tumors due to the inevitable irradiation of the heart, cannot be treated effectively using current clinical therapies. Here, we demonstrated that rhNRG-1ß, an epidermal growth factor (EGF)-like protein, protects myocardium tissue against irradiation-induced damage and preserves cardiac function. rhNRG-1ß effectively ameliorated irradiation-induced myocardial nuclear damage in both cultured adult rat-derived cardiomyocytes and rat myocardium tissue via NRG/ErbB2 signaling. By activating ErbB2, rhNRG-1ß maintained mitochondrial integrity, ATP production, respiratory chain function and the Krebs cycle status in irradiated cardiomyocytes. Moreover, the protection of irradiated cardiomyocytes and myocardium tissue by rhNRG-1ß was at least partly mediated by the activation of the ErbB2-ERK-SIRT1 signaling pathway. Long-term observations further showed that rhNRG-1ß administered in the peri-irradiation period exerts continuous protective effects on cardiac pump function, the myocardial energy metabolism, cardiomyocyte volume and interstitial fibrosis in the rats receiving radiation via NRG/ErbB2 signaling. Our findings indicate that rhNRG-1ß can protect the myocardium against irradiation-induced damage and preserve cardiac function via the ErbB2-ERK-SIRT1 signaling pathway.

SOCS3 Methylation Predicts a Poor Prognosis in HBV Infection-Related Hepatocellular Carcinoma.

Suppressor of cytokine signaling 3 (SOCS3) plays crucial roles in JAK/STAT signaling pathway inhibition in hepatocellular carcinoma (HCC). However, the methylation status of SOCS3 in HBV infection-related HCC and the relationship between SOCS3 methylation and the clinical outcome remain unknown. Here, we reported that in HCC tumor tissues, two regions of the CpG island (CGI) in the SOCS3 promoter were subjected to methylation analysis and only the region close to the translational start site of SOCS3 was hypermethylated. In HCC tumor tissues, SOCS3 showed an increased methylation frequency and intensity compared with that in the adjacent non-tumor tissues. Moreover, SOCS3 expression was significantly down-regulated in HCC cell lines and tumor tissues, and this was inversely correlated with methylation. Kaplan-Meier curve analysis revealed that in patients with an hepatitis B virus (HBV) infection background, SOCS3 hypermethylation was significantly correlated with a poor clinical outcome of HCC patients. Our findings indicated that SOCS3 hypermethylation has already happened in non-tumor tissues and increased in both frequency and intensity in tumor tissues. This suggests that the methylation of SOCS3 could predict a poor prognosis in HBV infection-related HCC patients.

Whole-liver radiotherapy concurrent with chemotherapy as a palliative treatment for colorectal patients with massive and multiple liver metastases: a retrospective study.

The purpose of this study was to investigate whether whole-liver radiotherapy plus a tumor-boost dose with concurrent chemotherapy is beneficial for colorectal cancer patients with massive and multiple liver metastases. From January 2007 to December 2012, 19 patients who exhibited massive (with a longest diameter > 5 cm) and invasive liver metastases and multiple metastases were treated with radiotherapy and concurrent chemotherapy. The total radiation dose was 53.4 Gy (range 38.8 Gy-66.3 Gy). All of the patients received a continuous intravenous dose of 5 fluorouracil (5-FU) 225 mg/m2 concurrently with radiation. The median survival time was 19 months. The 1- and 2- year overall survival rates were 78.3% and 14.3%, respectively. Of all of the patients who presented with abdominal pain, 100% experienced a decrease in pain. Decreases in the rates of ascites and jaundice were confirmed by ultrasound and bilirubin levels. No cases of Grade 4 or 5 acute or late toxicity were recorded. There were only two cases of Grade 3 toxicity (elevated bilirubin). These data provide evidence that whole-liver radiotherapy plus a tumor-boost dose with concurrent chemotherapy is beneficial for colorectal cancer patients with massive and multiple liver metastases.

Silencing of integrin-linked kinase suppresses in vivo tumorigenesis of human ovarian carcinoma cells.

Integrin-linked kinase (ILK) plays a role in the regulation of multiple cellular functions (e.g., promoting cell migration and proliferation, but inhibiting cell adhesion). This study investigated the inhibitory effects of ILK gene knockdown on the regulation of in vivo tumorigenesis of human ovarian carcinoma cells in nude mouse xenografts. HO-8910 cells were transfected with an ILK antisense oligonucleotide (ILK-ASO) to silence the ILK gene. Expression of ILK mRNA and protein was evaluated by RT-PCR and western blotting, respectively. The cell cycle was assessed by flow cytometric analysis. Cells with or without ILK-ASO transfection were subcutaneously injected into nude mice. The mouse body weight, tumor formation, tumor size and tumor weight were determined up to 30 days after inoculation. Tumor cells transfected with ILK-ASO had significantly decreased ILK mRNA and protein expression (P<0.01) when compared to the control cells. ILK gene silencing significantly increased the number of cells in the G0/G1 phase (67.61 vs. 43.29%, χ2=1197.15, P<0.01). After tumor cell inoculation, tumor cells transfected with ILK-ASO showed significantly delayed tumor formation when compared to control (9.10±0.74 vs. 5.30±0.67 days, respectively; P<0.01). In addition, tumor growth was suppressed in the 30 days following inoculation (P<0.01 compared with the controls). The average tumor weight in the ILK-ASO group was statistically lower than that of the control group (1.29±0.11 vs. 1.57±0.13 g, respectively; P<0.01). This study demonstrated that ILK-ASO transfection efficiently downregulated ILK expression in human ovarian carcinoma HO-8910 cells and that ILK gene silencing suppressed tumor growth in nude mice xenografts.

[Long-term results of personalized treatment in 72 breast cancer patients who failed chemotherapy].

OBJECTIVE: To evaluate the efficacy and prognostic factors of personalized treatment for breast cancer patients who failed chemotherapy. METHODS: Seventy-two patients with breast cancer who failed chemotherapy were treated at the Tumor Hospital of Harbin Medical University from January 2001 to January 2012. Among them, 42 cases received 5.6 cycles (range, 4-8 cycles) of postoperative adjuvant chemotherapy, and 30 cases received 12.2 cycles (range, 6-22 cycles), both postoperative adjuvant and salvage chemotherapy. All of the 72 patients of stage IV were given personalized treatment. Under guidance of the principle that multidisciplinary treatment improves control rate but does not or less damage the normal tissues and host immune function, precise radiotherapy combined with Chinese herbal medicine (CHM), biological agent and others were chosen for the patients. RESULTS: The median survival time was 20 months. Univariate analysis showed that non-invasive ductal carcinoma, less metastasized organs, without brain, liver and lung metastasis, Karnofsky performance scores ≥ 80, not combined with chemotherapy, and multiple courses of Chinese herbal medicine and biolojical agent treatment had significant impact on survival (P < 0.05). Multivariate analysis showed that no brain metastasis, non-invasive ductal carcinoma, and Chinese herbal medicine and biological agent treatment ≥ 7 courses and not combined with chemotherapy had obvious significance (P < 0.05). The rate of grade 3 and 4 treatment-related hematological toxicity was 8.3% (6/72) and 5.6% (4/72), respectively. All the patients with grade 4 hematological toxicity were the cases of grade 3 at hospital admission. No grade 3 and 4 acute radiation damages of the lung and liver were noticed. CONCLUSION: Chinese herbal medicine combined with biological agents and others prolongs survival time in breast cancer patients who failed chemotherapy, and provides an alternative treatment modality for them.