Objective To investigate the effects of X-ray dose on the expressions of microRNA-221 （miR-221） and phosphatase and a tensin homolog deleted from chromosome10 （PTEN） in human colorectal carcinoma （CRC） cells. Methods Human CRC-derived cell line， Caco2， was cultured conventionally. The cells were divided into five groups and exposed to different doses of X-ray （0， 2， 4， 6， and 8 Gy） respectively. The total RNA and protein of the Caco2 cells were extracted after irradiation， and the miR-221 and PTEN mRNA expressions were detected by real-time RT-PCR.Moreover， the protein alteration of PTEN in Caco2 cells was detected by Western-blot analysis. Results The radiation dose of X-ray significantly affected the expressions of miR-221 and PTEN protein in human Caco2 cells in a dose-depen-dent manner. Moreover， the miR-221 expression level was up-regulated gradually with the increase of irradiation dose， on the contrary， the PTEN protein expression level was down-regulated gradually （P＜0.01）. Conclusion The radiation dose can affect the miR-221 and PTEN protein expression pattern in CRC cells.
Objective To study the effects of peroxisome proliferators-activated receptor (PPAR) γ on the growth of human hepatocellular carcinoma cells and explore the roles of phosphatase and tensin homologue deleted on chromosome ten (PTEN) and phospho-Akt in this process. Methods SMMC-7721 cells were treated with 15-d-PGJ2 or pioglitazone, which were two kinds of PPARγ ligands, at different concentrations. The viability of SMMC-7721 cells was evaluated by MTT assay. The cell cycle was analyzed by flow cytometry. PTEN mRNA level was determined by RT-PCR. The protein expressions of PTEN and pAkt were measured by Western blot analysis. Results It was demonstrated through MTT assay that both 15-d-PGJ2 and pioglitazone had an inhibitory effect on the growth of SMMC-7721 cells in a time- and dose- dependent manner. According to flow cytometry detection, more cells were arrested in G0/G1 phase. Increased expression of PTEN mRNA was detected in 15-d-PGJ2 or pioglitazone-treated cells through RT-PCR. Increased expression of PTEN protein and decreased expression of pAkt were confirmed by Western blot analysis. Conclusion The ligands of PPARγ could inhibit SMMC-7721 cells proliferation in a time- and dose- dependent manner. The upregulation of PTEN may be involved in the underlying mechanism.
ObjectiveTo investigate PTEN expression and its relationship with clinicopathologic features in patients with gastric cancer. MethodsWe searched published studies in PubMed, EMbase, CNKI, VIP, WangFang Data and CBM from the day of establishment to July 24th, 2013. Some other relevant references were also searched to collect all the case-control studies. Two reviewers independently screened studies according to the inclusion and exclusion criteria, extracted data and assessed quality of the included studies independently. Then meta-analysis was conducted using RevMan 5.2 software. ResultsA total of 14 studies were recruited, which included 1 026 cases in the gastric cancer group and 539 cases in the normal gastric mucosa group. The results of meta-analysis showed that PTEN expression was lower in the gastric cancer group than in the normal gastric mucosa group, with a significant difference[OR=0.07, 95%CI (0.05, 0.10), P<0.000 01]. No significant difference was detected in age[OR=1.34, 95%CI (0.88, 2.04), P=0.17] and sex[OR=0.91, 95%CI (0.60, 1.36), P=0.64]. There were significant differences in terms of tumor length[OR=3.67, 95%CI (2.02, 6.67), P<0.000 1], histologic subtype[OR=3.54, 95%CI (2.56, 4.91), P<0.000 01], invasion depth[OR=3.36, 95%CI (2.41, 4.67), P<0.000 01], lymphatic metastasis[OR=4.11, 95%CI (2.98, 5.67), P<0.000 01], and TNM stage[OR=3.94, 95%CI (2.74, 5.65), P<0.000 01]. ConclusionPTEN expression reduces in gastric cancer, and its lower expression increases malignant behaviors of gastric cancer.
ObjectiveTo explore the influence mechanism of proliferation and invasion in colon cancer cell after silence of phosphatase and tensin homolog deleted on chromosome 10 (PTEN) gene. MethodsRT-PCR or Western blot method was used to detect the expression of PTEN mRNA or protein among four colon cancer cell lines (HT-29, WiDr, CaCo-2, and Colo320 cell lines). small interfering RNA (siRNA) was used to synthetize PTEN siRNA and transfect it into colon cancer cells. The expression of PTEN protein after transfecting was detected by Western blot. WsT-1 and invasion assay were used to examine the effects of PTEN siRNA silence on proliferation and invasion in colon cancer cells. ResultsPTEN mRNA and protein were expressed in all the four colon cancer cell lines. After PTEN siRNA transfected into the colon cancer cells, the expressions of PTEN proteins were inhibited in all the four colon cancer cell lines (P < 0.01), and the proliferation and invasion of colon cancer cells were enhanced significantly (P < 0.01). ConclusionsPTEN siRNA play an important role in metastasis process of colon cancer via enhanced its proliferation and invasion. Therefore, the understanding biologic mechanisms for regulation of PTEN might enable better molecular target therapy of treating the colon cancer patients with metastasis.
ObjectiveTo summarize and analyze the relevant studies about the tumor suppressor phosphatase and tensin homolog deleted on chromosome ten (PTEN) and thyroid tumor then further elucidate?the possible mechanism of thyroid tumor formation and progression. Mothods Domestic and international literatures investigating the correlation between PTEN and thyroid tumor were retrieved and reviewed. ResultsThe abnormal expression of PTEN protein resulted by the mutation or methylation of PTEN gene may up-regulate the expression of its downstream effectors such as PI3K, mTOR, FAK, etc. This probably correlate with thyroid neoplasia and progression. Conciusions Abnormalites of PTEN and its downstream signal ways may correlate with the initiation and development of thyroid tumors. However, the specific mechanism still remains unclear and need more further researches
ObjectiveTo detect expressions of PTEN and Ki-67 in primary thyroid cancer tissues and explore its clinical significances. MethodsThe expressions of PTEN protein and Ki-67 protein in 40 cases of paraffin-embedded tissues of primary thyroid cancer and the corresponding paracancerous tissues were detected by immunohistochemical method. The expressions of PTEN mRNA and Ki-67 mRNA in 14 cases of resected fresh tissues of primary thyroid cancer and the corresponding paracancerous tissues were detected by RT-PCR method. The relations between clinicopathologic characteristics and expression of PTEN protein or Ki-67 protein in the primary thyroid cancer tissues were analyzed. Results① The PTEN protein positive expression rate and the PTEN mRNA in the primary thyroid cancer tissues were significantly lower than those in the corresponding paracancerous tissues[35.0% (14/40) versus 60.0% (24/40), P<0.05; 0.225 7±0.036 3 versus 0.503 6±0.037 5, P<0.05], the Ki-67 protein positive expression rate and Ki-67 mRNA in the primary thyroid cancer tissues were significantly higher than those in the corresponding paracancerous tissues [72.5% (29/40) versus 42.5% (17/40), P<0.05; 1.212 1±0.042 1 versus 0.293 6±0.027 4, P<0.05]. ② The expressions of PTEN protein and Ki-67 protein were associated with the histological grading, pathological type, tumor stage, and presence of regional lymph node metastasis (P<0.05), which not associated with the patient's gender, age and integrity of tumor capsule or not (P>0.05). ③ The PTEN and Ki-67 protein expressions in the primary thyroid cancer tissues had a significantly negative correlation (rs=-0.605, P=0.000), which in the corresponding paracancerous tissues had no correlation (rs=-0.021, P=0.899). ConclusionPTEN and Ki-67 genes abnormally express in thyroid cancer tissue, which might be related with occurrence and development and its mechanism of primary thyroid cancer. Combination of two genes might contribute to identification of pathologic type, judge of biological behavior, and tumor stage of primary thyroid cancer, which might serve as a new target for diagnosis and treatment of it.
Objective To investigate the effect of ginkgolide B (GB) on cysteinyl aspartate specific proteinase-3 (Caspase-3)/chromosome 10 deletion phosphatase-tension protein homologue (PTEN)/protein kinase B (Akt) pathway and cell proliferation and apoptosis in hypoxia/reoxygenation cardiomyocytes. Methods H9C2 cells were cultured in vitro. A control group was cultured in serum-free DMEM high glucose medium at 37°C and 5% CO2 for 28 hours. The remaining groups were prepared with hypoxia/reoxygenation models. A GB low-dose group and a GB high-dose group were treated with GB pretreatment with final concentration of 50 μmol/L and 200 μmol/L respectively at 1 h before hypoxia/reoxygenation. A carvedilol group was treated with carvedilol of a final concentration of 10 μmol/L at 1 h before hypoxia/reoxygenation. The proliferation and apoptosis of H9C2 cells were detected, and the levels of lactate dehydrogenase (LDH), malondialdehyde (MDA), reactive oxygen species (ROS), PTEN, Akt, phosphorylated Akt (p-Akt) and Caspase-3 in H9C2 cells were also detected. Results Compared with the control group, the proliferation rate of H9C2 cell, and the levels of PTEN, Akt and p-Akt in other groups decreased, and the apoptosis rate, and the levels of LDH, MDA, ROS and Caspase-3 increased (P<0.05). Compared with the hypoxia/reoxygenation group, the proliferation rate of H9C2 cell, and the levels of PTEN, Akt and p-Akt in all GB dose groups and the carvedilol group increased; the apoptosis rate, and the levels of LDH, MDA, ROS and Caspase-3 decreased, and the effect of GB was in a dose dependent manner; however, the effect of GB was not as strong as carvedilol (P<0.05). Conclusion GB can inhibit H9C2 cell apoptosis and promote H9C2 cell proliferation by activating Caspase-3/PTEN/Akt pathway.
The aim of this study is to determine the regulatory mechanism of PTEN-induced putative kinase protein 1 short isoform (PINK1S) in cytoplasm. By co-immunoprecipitation (Co-IP) assay, we identified that PINK1S interacted with the beta regulatory subunit of Casein Kinase 2 (CK2β), but not with the catalytic subunits CK2α1 and CK2α2. Furthermore, cells were transfected with PINK1S and CK2β, and then PINK1S was purified by immunoprecipitation. After detecting the phosphorylated proteins by Phos-tagTM Biotin, we found that CK2β overexpression increased auto-phosphorylation of PINK1S. Finally, we generated CK2β knockdown cell lines by RNA interference. Purified PINK1S from CK2β knockdown cells significantly reduced its auto-phosphorylation compared with control cells. These results suggested that CK2β functions as a regulatory subunit of PINK1S kinase complex promoted its activation by self-phosphorylation.