Effect of c-Ski on atrial remodelling in a rapid atrial pacing canine model.

Atrial fibrosis is an important factor in the initiation and maintenance of atrial fibrillation (AF); therefore, understanding the pathogenesis of atrial fibrosis may reveal promising therapeutic targets for AF. In this study, we successfully established a rapid atrial pacing canine model and found that the inducibility and duration of AF were significantly reduced by the overexpression of c-Ski, suggesting that this approach may have therapeutic effects. c-Ski was found to be down-regulated in the atrial tissues of the rapid atrial pacing canine model. We artificially up-regulated c-Ski expression with a c-Ski-overexpressing adenovirus. Haematoxylin and eosin, Masson's trichrome and picrosirius red staining showed that c-Ski overexpression alleviated atrial fibrosis. Furthermore, we found that the expression levels of collagen III and α-SMA were higher in the groups of dogs subjected to right-atrial pacing, and this increase was attenuated by c-Ski overexpression. In addition, c-Ski overexpression decreased the phosphorylation of smad2, smad3 and p38 MAPK (p38α and p38ß) as well as the expression of TGF-ß1 in atrial tissues, as shown by a comparison of the right-atrial pacing + c-Ski-overexpression group to the control group with right-atrial pacing only. These results suggest that c-Ski overexpression improves atrial remodelling in a rapid atrial pacing canine model by suppressing TGF-ß1-Smad signalling and p38 MAPK activation.

Inhibitory effects of candesartan on KCa3.1 potassium channel expression and cell culture and proliferation in peripheral blood CD4+T lymphocytes in Kazakh patients with hypertension from the Xinjiang region.

BACKGROUND AND AIM: Increasing evidence confirms that potassium channels are essential for lymphocyte activation, suggesting an involvement in the development of hypertension. Moreover, chronic inflammation is regarded as a direct or indirect manifestation of hypertension, highlighting the theoretical mechanisms. In this study, we investigated changes in KCa3.1 potassium channel expression in the blood of hypertensive and healthy Kazakh people in north-west China. METHODS: Flow cytometry technology was used for T-lymphocyte subtype analysis. Changes in the messenger RNA and protein expression of the KCa3.1 potassium channel in CD4+ T lymphocytes were detected using real-time quantitative polymerase chain reaction and western blots, using CD4+ T-cell samples from hypertensive Kazakh patients divided into candesartan and TRAM-34 treatment groups, and healthy case controls. Peripheral blood CD4+ T lymphocytes were activated and proliferated in vitro and then incubated for 0, 24, and 48 h under various treatment conditions. Changes in CD4+ T-lymphocytic proliferation were determined using Cell Counting Kit-8 and electron microscope photography. RESULTS: Expression of KCa3.1 was significantly higher in the hypertensive patients than in the controls (p < 0.05). Compared with the healthy group, Kazakh hypertensive patients had a reduced proportion of CD4+ T lymphocytes (p < 0.05).Candesartan and TRAM-34 intervention for 24 h and 48 h inhibited the expression of Kv1.3 and KCa3.1 at mRNA and protein level (p < 0.05). CONCLUSIONS: Increase in functional KCa3.1 channels expressed in CD4+ T lymphocytes of Kazakh patients with hypertension was blocked by candesartan, providing theoretical support for hypertension treatment at the cellular ion channel level. Candesartan may potentially regulate hypertensive inflammatory responses by inhibiting T-lymphocytic proliferation and KCa3.1 potassium channel expression in CD4 + T lymphocytes.

The role of RCAS1 as a biomarker in diagnosing CRC and monitoring tumor recurrence and metastasis.

Receptor-binding cancer antigen expressed on SiSo cells (RCAS1) plays an important role in tumor progression by helping tumor cell to escape from host immunological surveillance or modifying the characteristics of connective tissue around. RCAS1 may appropriately reflect the development and prognosis of tumor. In the study, we sought to identify the clinical significance of RCAS1 in colorectal cancer (CRC) diagnosis and tumor recurrence monitoring. Immunohistochemistry (IHC) with tissue array slides was preformed to analyze RCAS1 protein expression in CRC, colorectal polyps, and normal colon tissues. RCAS1 levels in colorectal cancer were significantly higher than those in colorectal polyps and normal colon tissues (P<0.001). Silencing RCAS1 gene in human colonic adenocarcinoma cells decreased cell proliferation and enhanced apoptosis through the p53 signaling pathway. Further analysis by an enzyme-linked immunosorbent assay (ELISA) showed that serum RCAS1 levels in CRC are significantly higher than in healthy controls and polyps (P<0.05), in which the highest serum RCAS1 level is reported in the recurrence group. The serum RCAS1 levels have a significant correlation with clinical stage and pathologic grading. Furthermore, the positive rate of serum RCAS1 in CRC was 82.1 %, which was higher than carcinoembryonic antigen (CEA). Especially in CEA-negative cases, the sensitivity of RCAS1 was 88.2 %. Finally, CRC patients who were followed up showed a serum RCAS1 level which significantly decreased after surgery (P<0.001) and obviously increased in the recurrence group. Taken together, our data demonstrated that RCAS1 is not only a supplementary serological biomarker for CRC diagnosis but also useful for monitoring tumor recurrence. RCAS1 might be a supplementary serological marker for CRC.

Metformin enhances T lymphocyte anti-tumor immunity by increasing the infiltration via vessel normalization.

Abnormal tumor vasculature blocks the extravasation of T lymphocytes into the tumor, thereby suppressing anti-tumor immunity. Recently, metformin has been shown to affect tumor vasculature and enhance T lymphocyte anti-tumor immunity. However, whether or how metformin affects T lymphocyte anti-tumor immunity via a vascular mechanism remains poorly understood. Herein, we show that a large number of CD8+ lymphocytes gathered in the peri-tumoral region, while very few infiltrated the tumor. Metformin administration increased the expression of anti-tumor immunity-associated genes and the number of tumor-infiltrating CD8+ lymphocytes. Injection of CD8 but not CD4 neutralization antibody into tumor-bearing mice significantly abrogated the anti-tumor effect of metformin. Critically, CD8+ lymphocytes were found to pass through the wall of perfused vessel. Further results of immunofluorescent staining showed that metformin greatly elevated tumor perfusion, which was accompanied by increased vascular maturity in the intratumoral region (ITR) but not peritumoral region (PTR). These findings provide evidence for the vascular mechanism involved in metformin-induced enhancement of T lymphocyte anti-tumor immunity. By remodeling the abnormal tumor vasculature, also called vessel normalization metformin increases vascular maturity and tumor perfusion, thus allowing more CD8+ lymphocytes to infiltrate the tumor.

Strategies for targeting the DNA damage response for cancer therapeutics.

The DNA damage response is critical for cells to maintain genome stability and survival. In this review, we discuss approaches to targeting critical elements of the DNA damage response for radiosensitization and chemosensitization. In addition, we also discuss strategies for targeting DNA damage response and DNA repair defects in cancer cells for synthetic lethality.

Role of Twist in vasculogenic mimicry formation in hypoxic hepatocellular carcinoma cells in vitro.

Vasculogenic mimicry (VM) refers to the unique ability of highly aggressive human tumor cells to form matrix-rich networks de novo when cultured on a three-dimensional matrix, thus mimicking embryonic vasculogenesis. Some studies have shown that tumor hypoxia can promote tumor cells to form vessel-like tubes in vitro and express genes associated with VM. Although, the mechanisms involved in hypoxia-induced VM remain elusive, we hypothesized that the epithelial-mesenchymal transition (EMT) regulator Twist may play a major role in hypoxia-induced VM. We investigated this hypothesis in vitro by pretreating hepatocellular carcinoma cells under hypoxic conditions. Following the hypoxia treatment, the cells formed typical pipe-like VM networks. Moreover, the expression of VM markers was increased. Hypoxia-induced VM was accompanied by the increased expression of Twist. Twist siRNA reversed the effects of hypoxia on VM. These results suggest that the overexpression of Twist correlates to hypoxia-induced VM in hepatocellular carcinoma cells.

Losartan attenuates chronic cigarette smoke exposure-induced pulmonary arterial hypertension in rats: possible involvement of angiotensin-converting enzyme-2.

Chronic cigarette smoking induces pulmonary arterial hypertension (PAH) by largely unknown mechanisms. Renin-angiotensin system (RAS) is known to function in the development of PAH. Losartan, a specific angiotensin II receptor antagonist, is a well-known antihypertensive drug with a potential role in regulating angiotensin-converting enzyme-2 (ACE2), a recently found regulator of RAS. To determine the effect of losartan on smoke-induced PAH and its possible mechanism, rats were daily exposed to cigarette smoke for 6months in the absence and in the presence of losartan. Elevated right ventricular systolic pressure (RVSP), thickened wall of pulmonary arteries with apparent medial hypertrophy along with increased angiotensin II (Ang II) and decreased ACE2 levels were observed in smoke-exposed-only rats. Losartan administration ameliorated pulmonary vascular remodeling, inhibited the smoke-induced RVSP and Ang II elevation and partially reversed the ACE2 decrease in rat lungs. In cultured primary pulmonary artery smooth muscle cells (PASMCs) from 3- and 6-month smoke-exposed rats, ACE2 levels were significantly lower than in those from the control rats. Moreover, PASMCs from 6-month exposed rats proliferated more rapidly than those from 3-month exposed or control rats, and cells grew even more rapidly in the presence of DX600, an ACE2 inhibitor. Consistent with the in vivo study, in vitro losartan pretreatment also inhibited cigarette smoke extract (CSE)-induced cell proliferation and ACE2 reduction in rat PASMCs. The results suggest that losartan may be therapeutically useful in the chronic smoking-induced pulmonary vascular remodeling and PAH and ACE2 may be involved as part of its mechanism. Our study might provide insight into the development of new therapeutic interventions for PAH smokers.

Role of chymase in cigarette smoke-induced pulmonary artery remodeling and pulmonary hypertension in hamsters.

BACKGROUND: Cigarette smoking is an important risk factor for pulmonary arterial hypertension (PAH) in chronic obstructive pulmonary disease (COPD). Chymase has been shown to function in the enzymatic production of angiotensin II (AngII) and the activation of transforming growth factor (TGF)-beta1 in the cardiovascular system. The aim of this study was to determine the potential role of chymase in cigarette smoke-induced pulmonary artery remodeling and PAH. METHODS: Hamsters were exposed to cigarette smoke; after 4 months, lung morphology and tissue biochemical changes were examined using immunohistochemistry, Western blotting, radioimmunoassay and reverse-transcription polymerase chain reaction. RESULTS: Our results show that chronic cigarette smoke exposure significantly induced elevation of right ventricular systolic pressures (RVSP) and medial hypertrophy of pulmonary arterioles in hamsters, concurrent with an increase of chymase activity and synthesis in the lung. Elevated Ang II levels and enhanced TGF-beta1/Smad signaling activation were also observed in smoke-exposed lungs. Chymase inhibition with chymostatin reduced the cigarette smoke-induced increase in chymase activity and Ang II concentration in the lung, and attenuated the RVSP elevation and the remodeling of pulmonary arterioles. Chymostatin did not affect angiotensin converting enzyme (ACE) activity in hamster lungs. CONCLUSIONS: These results suggest that chronic cigarette smoke exposure can increase chymase activity and expression in hamster lungs. The capability of activated chymase to induce Ang II formation and TGF-beta1 signaling may be part of the mechanism for smoking-induced pulmonary vascular remodeling. Thus, our study implies that blockade of chymase might provide benefits to PAH smokers.

[Effects of cyclic mechanical stretch on the activity of STAT3 in human bronchial epithelial cell (16HBEC)].

OBJECTIVE: To study the effects of cyclic mechanical stretch on the activity and expression of STAT3 in Human bronchial epithelial Cell (16HBEC). METHODS: The 16HBECs were subjected to cyclic mechanical stretch by the four-point bending system at 0.5 Hz of 1 kPa, 2 kPa, 3 kPa, 4 kPa for 30 min or for 30 min, 1 h, 3 h, and 6 h of 3 kPa respectively. The mRNA level of STAT3 was semi-quantified by RT-PCR; STAT3 protein and phosphorylated STAT3 were detected by western blot. RESULTS: Phosphorylation level of STAT3 Tyr705 was higher under 3 kPa cyclic mechanical stretch than the others. 3 kPa stretch phosphorylatd STAT3 Tyr705 in 16HBE cells in a time-dependent manner. The phosphorylation of STAT3-Tyr705 was significantly increased at 30 min compared with the control group (P<0.05), and reached the highest phosphorylation level at 1 h, then showed a sharp descending tendency. There was no effect of 3 kPa stretch on the phosphorylation of STAT3 Ser727, expression of STAT3 protein or mRNA levels. CONCLUSION: STAT3 played an important role in the response and signal transduction of 16HBECs to the cyclic mechanical stretch stimulation through the phosphorylation of STAT3 Tyr705.

[Effects of ERK and STAT3 on cell signal transduction in alveolar epithelium A549 cells stimulated by mechanical force].

OBJECTIVE: To observe the effect of mechanical force on the expression of p-ERK and p-STAT3 when pulmonary epithelium A549 cells were subjected to tensile stress. METHODS: By the self-made four-point bending system, the A549 cells were subjected to cyclic tensile stress of 3000 microstrain for 30 min, 1 h, 2 h or 4 h respectively, then the total protein of each time point was collected and the expression of p-ERK and p-STAT3 were detected by Western blot analysis. RESULTS: (1) The expression of p-ERK was activated at 1 h and remained at a high level until 4 h. (2) The expression of p-STAT3 (Ser) was activated at 30 min and remained at a high level until 4 h. CONCLUSION: Tensile stress can activate the expression of p-ERK and p-STAT3 (Ser) in alveolar epithelium A549 cells. ERK and STAT3 may participate in the cell mechanotransduction in A549 cells.

[Association between interleukin-8 in lung tissues and stages of chronic obstructive pulmonary diseases].

OBJECTIVE: To investigate the expression of interleukin (IL)-8 in lung tissues from patients with chronic obstructive pulmonary disease (COPD) and its association with stages of COPD. METHODS: The levels of mRNA and protein of IL-8 were measured with semi-quantitative polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) in patients with mild COPD (n=21), patients with advanced COPD (n=15), and controls (n=15). The correlations between IL-8 levels and stages of COPD, lung function (FEV1/ FVC%, FEV1% pred) and cigarette smoking were analyzed with Pearson correlation analysis. RESULTS: The levels of IL-8 mRNA and protein in the lung tissues of COPD patients were significantly higher than those in the control group (P<0.05). The patients with advanced COPD had higher levels of IL-8 mRNA and protein than the patients with mild COPD (P<0.05). The COPD patients who smoked had higher levels of IL-8 mRNA and protein than those who did not smoke (P<0.05). But no significant differences in the levels of IL-8 mRNA and protein were found between smokers and and nonsmokers who did not have COPD (P>0.05). Increased expression of IL-8 in patients with COPD was positively correlated with stages of COPD (r=0.81, P<0.05); negatively correlated with lung function (FEV1/FVC%, FEV1% pred) (r=-0.62, -0.56, P<0.05), and positively correlated with volumes of cigarette smoking (r=0.53, P<0.05). CONCLUSION: IL-8 is associated with stages of COPD, which may serve as an indication for clinical progress. Cigarette smoking increases IL-8 expression in the lung tissues of COPD patients.

Evaluation of the target genes of arsenic trioxide in pancreatic cancer by bioinformatics analysis.

The aim of the present study was to evaluate the potential network of arsenic trioxide (ATO) target genes in pancreatic cancer. The DrugBank, STITCH, cBioPortal, Kaplan-Meier plotter and Oncomine websites were used to analyze the association of ATO and its target genes with pancreatic cancer. Initially, 19 ATO target genes were identified, along with their associated protein-protein interaction networks and Kyoto Encyclopedia of Genes and Genomes pathways. ATO was found to be associated with multiple types of cancer, and the most common solid cancer was pancreatic cancer. A total of 6 ATO target genes (namely AKT1, CCND1, CDKN2A, IKBKB, MAPK1 and MAPK3) were found to be associated with pancreatic cancer. Next, the mutation information of the 6 ATO target genes in pancreatic cancer was collected. A total of 20 ATO interacting genes were identified, which were mainly involved in hepatitis B, prostate cancer, pathways in cancer, glioma and chronic myeloid leukemia. Finally, the genes CCND1 and MAPK1 were detected to be prognostic factors in patients with pancreatic cancer. In conclusion, bioinformatics analysis may help elucidate the molecular mechanisms underlying the involvement of ATO in pancreatic cancer, enabling more effective treatment of this disease.

NTRK1 is a positive regulator of YAP oncogenic function.

Multiple cancer signalling networks take part in regulatory crosstalks with the Hippo tumour suppressor pathway through the transcriptional cofactor Yes-associated protein (YAP). Nevertheless, how YAP is controlled by pathway crosstalks in tumourigenesis remains poorly understood. Here, we performed a targeted kinase inhibitor screen in human cancer cells to identify novel Hippo pathway regulators. Notably, we identified the nerve growth factor (NGF) receptor tyrosine kinase (NTRK1), a molecule not previously associated with Hippo signalling. NTRK1 inhibition decreased YAP-driven transcription, cancer cell proliferation and migration. Furthermore, using a complementary functional genomics approach and mouse xenograft models, we show that NTRK1 regulates YAP oncogenic activity in vivo. Mechanistically, NTRK1 inhibition was found to induce large suppressor kinase 1 (LATS1) phosphorylation and to control YAP subcellular localization. Taken together, these results provide compelling evidence of crosstalks between the NGF-NTRK1 and Hippo cancer pathways.

Metformin inhibits metastatic breast cancer progression and improves chemosensitivity by inducing vessel normalization via PDGF-B downregulation.

BACKGROUND: Vascular maturity and functionality are closely associated with tumor progression and chemosensitivity. The antidiabetic agent metformin has shown its ability to inhibit tumor angiogenesis in metastatic breast cancer models. However, it remains unclear if or how metformin remodels the abnormal vasculature of metastatic breast cancer, while inhibiting angiogenesis. METHODS: Metastatic breast cancer models were constructed to compare microvessel density (MVD), vascular maturity and function, lung metastasis and chemosensitivity in metformin-treated or untreated mice. Protein array assay and transcriptome sequencing were performed for genetic screening. Lentiviral shRNA-PDGF-B transfection was used for observing the contribution of PDGF-B knockdown to metformin's vascular effects. RESULTS: Metastatic breast cancers were characterized by an excessively angiogenic, immature and morphologically abnormal vasculature. Compared to control, metformin significantly reduced MVD, leakage and hypoxia, and increased vascular mural cells coverage and perfusion, namely, "vessel normalization". Metformin at human blood concentrations had no direct effect on the migration and proliferation of cancer cells. Based on that, reduced lung metastasis of the primary tumor and improved chemosensitization by metformin were assumed to be mediated via metformin's vascular effects. Further results of genetic screening and in vivo experiments showed that the downregulation of platelet-derived growth factor B (PDGF-B) greatly contributed to the metformin-induced vessel normalization. CONCLUSIONS: These findings provide pre-clinical evidences for the vascular mechanism of metformin-induced metastasis inhibition and the chemosensitization of metastatic breast cancers.

Secretory Transactivating Transcription-apoptin fusion protein induces apoptosis in hepatocellular carcinoma HepG2 cells.

AIM: To determine whether SP-TAT-apoptin induces apoptosis and also maintains its tumor cell specificity. METHODS: In this study, we designed a secretory protein by adding a secretory signal peptide (SP) to the N terminus of Transactivating Transcription (TAT)-apoptin (SP-TAT-apoptin), to test the hypothesis that it gains an additive bystander effect as an anti-cancer therapy. We used an artificial human secretory SP whose amino acid sequence and corresponding cDNA sequence were generated by the SP hidden Markov model. RESULTS: In human liver carcinoma HepG2 cells, SP-TAT-apoptin expression showed a diffuse pattern in the early phase after transfection. After 48 h, however, it translocated into the nuclear compartment and caused massive apoptotic cell death, as determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and annexin-V binding assay. SP-TAT-apoptin did not, however, cause any cell death in non-malignant human umbilical vein endothelial cells (HUVECs). Most importantly, the conditioned medium from Chinese hamster ovary (CHO) cells transfected with SP-TAT-apoptin also induced significant cell death in HepG2 cells, but not in HUVECs. CONCLUSION: The data demonstrated that SP-TAT-apoptin induces apoptosis only in malignant cells, and its secretory property might greatly increase its potency once it is delivered in vivo for cancer therapy.

High levels of serum glypican-1 indicate poor prognosis in pancreatic ductal adenocarcinoma.

Carbohydrate antigen 19-9 (CA19-9) fails to demonstrate the predictive value for early detection pancreatic ductal adenocarcinoma (PDAC). Glypican-1 (GPC1+) exosomes may serve as a noninvasive diagnostic tool to detect early stages of PDAC. Therefore, it is necessary to explore the serum GPC1 levels and determine whether serum GPC1 serves as a novel biomarker for PDAC patients. Blood samples were collected from 156 patients with PDAC, 199 non-cancer controls, and 240 patients with other cancers. Serological levels of GPC1 were examined by enzyme-linked immunosorbent assay (ELISA). Finally, a 5-year follow-up was monitored to evaluate the correlation between serum GPC1 levels and overall survival in 156 patients with PDAC. The results suggested that levels of serum GPC1 and CA19-9 were higher in PDAC patients than that of controls (P < 0.05). Serum GPC1 levels in PDAC were different from those in gallbladder carcinoma (P < 0.001), colorectal carcinoma (P < 0.001), gastric carcinoma (P < 0.001), and prostate cancer (P < 0.001), but not hepatocellular carcinoma (P = 0.395) and cholangiocarcinoma (P = 0.724). Receiver operating characteristic curve (ROC) analysis showed that serum CA19-9 was significantly better than serum GPC1 in distinguishing PDAC patients from the controls (AUC, 95% CI: 0.908, 0.868-0.947 vs 0.795, 0.749-0.841, respectively). The serum GPC1 cannot be used as a serum diagnostic biomarker for PDAC patients. The level of serum GPC1 decreased 2 days after surgery (P = 0.001), which were not different from serum GPC1 levels in healthy control (P = 0.381). The overall survival rate was shorter in patients with high levels of serum GPC1 compared to those with low levels of serum GPC1 (log-rank = 5.16, P = 0.023). Taken together, the results indicate that high levels of serum GPC1 predict poor prognosis in PDAC patients. Serum GPC1 may be a prognosis factor for PDAC patients.

Autoantibodies against glucose-regulated protein 78 as serological biomarkers in metastatic and recurrent hepatocellular carcinoma.

PURPOSE: To identify Heptocellular carcinoma (HCC) associated antigens by proteomics, and validate whether autoantibodies against tumor-associated antigens (TAAs) could be used for diagnosis and conditional monitoring. RESULTS: The 78 kDa glucose regulated protein (GRP78) was selected as a candidate TAA. The titers of autoantibodies against 78 kDa glucose regulated protein (GRP78) from patients with HCC, liver cirrhosis (LC), and chronic hepatitis (CH) were significantly higher than that from normal controls (P<0.05, P<0.001, and P<0.01, respectively). The expression of autoantibodies against GRP78 was associated with clinical stage (P<0.01), portal vein invasion (P<0.05), and metastasis (P<0.05). The expression of anti-GRP78 antibodies was significantly higher 1 month after surgery in recurrent patients who had accepted hepatic resection 1 month after surgery compared to patients who had surgery before surgery or within 1 week after surgery (P<0.01 and P<0.001). Immunohistochemistry (IHC) showed higher expression of GRP78 in HCC compared to the non-HCC liver tissues (P <0.05). MATERIALS AND METHODS: HCC serum with high titer of autoantibodies against TAAs were screened and used for a proteome-based approach to identify HCC associated antigens. Indirect enzyme-linked immunoassay (ELISA) was used to detect the corresponding autoantibodies against TAAs. CONCLUSION: GRP78 is an autoantigen that could stimulate autoimmune responses and serve as a potential marker for recurrent and metastatic progression in HCC.

MicroRNA-326 functions as a tumor suppressor in colorectal cancer by targeting the nin one binding protein.

Accumulating evidence has demonstrated that microRNAs (miRNAs) are involved in multiple processes in cancer development and progression. miR-326 has been identified as a tumor suppressor miRNA in several types of human cancer. However, the specific function of miR-326 and its target the nin one binding protein (NOB1) in colorectal carcinoma (CRC) remains unclear. In the present study, we found that miR-326 inhibited cell proliferation, migration and invasion, and induced cell apoptosis and cell cycle arrest of CRC cells by directly targeting NOB1. Furthermore, the upregulation of miR-326 in CRC cells was revealed to be associated with a feedback loop involving downregulation of the NOB1, which mimics the phenotype induced by miR-326. Importantly, we found that the CRC patients with high expression of miR-326 or low expression of NOB1 tend to obtain a better prognosis. Thus, for the first time, we provide convincing evidence that downregulation of miR-326 inhibited tumor proliferation and tumor metastasis by directly targeting NOB1 in CRC. NOB1 and miR-326 could be potential therapeutic targets for CRC.

MiR-21 promotes intrahepatic cholangiocarcinoma proliferation and growth in vitro and in vivo by targeting PTPN14 and PTEN.

Intrahepatic cholangiocarcinoma (ICC) constitutes the second-most common primary hepatic malignancy. MicroRNAs (miRNAs) play important roles in the pathogenesis of ICC. However, the clinical significance of miR-21 levels in ICC remains unclear. Here, we investigated the role of miR-21 in ICC and found that its expression was significantly upregulated in serum of ICC patients. Serum miR-21 levels robustly distinguished ICC patients from control subjects. Further experiments showed that inhibition of miR-21 suppressed ICC cell proliferation in vitro and tumor growth in vivo. Specifically, inhibition of miR-21 induced cell cycle arrest and apoptosis. Moreover, PTPN14 and PTEN were identified as direct and functional targets of miR-21. Finally, we showed high expression levels of miR-21 were closely related to adverse clinical features, diminished survival, and poor prognosis in ICC patients. This study revealed functional and mechanistic links between miR-21 and tumor suppressor genes, PTPN14 and PTEN, in the pathogenesis of ICC. MiR-21 not only plays important roles in the regulation of cell proliferation and tumor growth in ICC, but is also a diagnostic and prognostic marker, and a potential therapeutic target for ICC.

Autoimmune response to PARP and BRCA1/BRCA2 in cancer.

PURPOSE: To determine the role of autoantibodies to PARP1 and BRCA1/BRCA2 which were involved in the synthetic lethal interaction in cancer. METHODS: Enzyme-Linked Immunosorbent Assay (ELISA) was used to detect autoantibodies to PARP1 and BRCA1/BRCA2 in 618 serum samples including 131 from breast cancer, 94 from lung cancer, 34 from ovarian cancer, 107 from prostate cancer, 76 from liver cancer, 41 from pancreatic cancer and 135 from normal individuals. The positive sera with ELISA were confirmed by Western blot. Immunohistochemistry was used to examine the expression of PARP1 and BRCA1/BRCA2 in breast cancer. RESULTS: Autoantibody frequency to PARP1, BRCA1, and BRCA2 in cancer varied from 0% to 50%. When the sera from cancer patients were tested for the presence of autoantibodies to PARP1 and BRCA1/BRCA2, the autoantibody responses slightly decreased and the positive autoantibody reactions varied from 0% to 50.0%. This was significantly higher autoantibody responses to PARP1 and BRCA1/BRCA2 (especially to PARP1 and BRCA1) in ovarian cancer and breast cancer compared to normal control sera (P < 0.001 and P < 0.01). Immunohistochemistry indicated that Pathology Grade at diagnosis to PARP1 expression in breast cancer was different (P < 0.05). CONCLUSIONS: Different cancers have different profiles of autoantibodies. The autoantibodies to proteins involving the synthetic lethal interactions would be novel serological biomarker in some selective cancers.