Clinical significance of p27 Kip1 expression in advanced ovarian cancer

Background: Ovarian cancer is the most common gynecological malignancy. In patients with advanced ovarian cancer, some biological parameters have prognostic implementations. P27kip1 is an inhibitor of a cycline-dependent kinase, its loss, can contribute to tumor progression. Objective: This study aimed to examine the importance of P27KIP1 protein in predicting the prognosis and response to neoadjuvant chemotherapy in patients with advanced ovarian epithelial cancer and to compare the outcomes of immunohistochemistry with Quantitative Real-time PCR. Patients and methods: We have studied P27KIP1expression by both immunohistochemistry and Quantitative Realtime PCR from 88 patients with advanced ovarian carcinomas undergone radical debulking surgery and received Paclitaxel followed by Cisplatin every 3 weeks for a total of 6 cycles. We also studied their association with both chemotherapy response and patient survival. Results: Nuclear expression of p27KIP1 protein was intense in 86 normal ovarian tissues and 42 of 88 carcinomas. The P27kip1mRNA expression level by qRT-PCR was very low in ovarian cancer tissues relative to its adjacent normal tissues. The results were statistically significant by both methods of determination. p27KIP1 expression was significantly related to good prognostic parameters as low stage tumors, differentiated tumors, absence of ascites, residual disease < 2 cm, and response to chemotherapy but not with histopathological type in case of determination by immunohistochemistry. Comparison of P27kip1 by both immunohistochemistry and qRTPCR with different prognostic parameters revealed no significant difference between both methods in the assessment of these parameters. In 4 years of follow-up, 20.5% of patients were alive without evidence of disease. 6.8% were alive with disease. The disease-related four -year survival rate for the whole group was 28.2%. In multivariate analysis, residual disease, histological type, tumor differentiation, ascites was of independent prognostic significance. Conclusion: In ovarian cancer, patients with loss of p27KIP1 expression are at a greater likelihood of disease progression, p27KIP1 may be used as a molecular marker to predict response to chemotherapy and prognosis. Both immunohistochemistry and qRT-PCR have equal reliability in the determination of p27 KIP1

Skp2 inhibitor SKPin C1 decreased viability and proliferation of multiple myeloma cells and induced apoptosis

Multiple myeloma (MM) is a malignant neoplasm of plasma, and exhibits several harmful effects including osteolytic injuries, hypercalcemia, and immune dysfunction. Many patients with MM succumb to the underlying malignancy. An S-phase kinase-related protein 2 (Skp2) inhibitor, designated SKPin C1, has been developed and confirmed to have an inhibitory effect on metastatic melanoma cells. This study aimed to determine the effect of SKPin C1 on MM. Normal B lymphocytes, THP-1 cells, and MM U266 and RPMI 8226 cells were exposed to various dosages of SKPin C1 for 48 h. Cell proliferation was determined by MTT, EdU staining, and cell cycle assays. Western blot assays were performed to assess intracellular protein levels of Skp2, p27, and cleaved caspase-3. The amount of ubiquitin attached to p27 was determined using an immunoprecipitation assay. The viability of U266 and RPMI 8226 cells was significantly inhibited by 10 μM SKPin C1 and the inhibitory effect was enhanced with increasing doses of SKPin C1. In contrast, 50 μM SKPin C1 only marginally decreased viability of normal B lymphocytes in 12 h. Skp2 and p27 expression in U266 and RPMI 8226 cells was higher and lower, respectively, than that in the normal B lymphocytes. Treatment with SKPin C1 or Skp2 knockdown increased p27 protein levels in U266 and RPMI 8226 cells by preventing p27 from being ubiquitinated, which slowed the cell cycle, inhibited cell proliferation, and triggered apoptosis. Therefore, this study suggested SKPin C1 as a potent inhibitor against aberrant proliferation and immortalization of MM.

Growth Inhibition of Hepatocellular Carcinoma Huh7 Cells by Lactobacillus casei Extract

PURPOSE: Lactobacillus casei (L. casei) is known to exert anti-proliferation effects on many types of cancer cells. However, the effect of L. casei on liver cancer has not been reported. Accordingly, the aim of this study was to determine the anti-cancer effect of L. casei extract on Huh7 cells. MATERIALS AND METHODS: L. casei ATCC393 extract was prepared and purified. After the treatment of L. casei extract on Huh7 cells, cell viability, cell cycle arrest and cell death were analyzed by flow cytometry. The expression levels of tumor necrosis factor-alpha receptor 1 (TNFR1) and death receptor 3 (DR3) mRNA related with extrinsic apoptosis were assessed by reverse transcription polymerase chain reaction. Additionally, P21 and P27 cell cycle proteins as well as Caspase-3, -8, -9, phospho-Bad and Bcl-2 apoptosis proteins were analyzed by western blot analysis. To determine the effect of L. casei extract on cancer stem-like cells, we analyzed changes in side population fraction through flow cytometry. RESULTS: The cell viability of Huh7 cells treated with L. casei extract was decreased by 77%, potentially owing to increases in the rates of Huh7 cells arrested in the G2/M phase (3% increase) and that underwent apoptosis (6% increase). The expression levels of TNFR1 and DR3 mRNA, as well as P21 and P27 cell cycle proteins, were increased. Meanwhile, the expressions of caspase-8, -9, phospho-Bad and Bcl-2 proteins decreased. However, in the case of side population cells, no remarkable changes were observed. CONCLUSION: L. casei extract exerts a potent anti-tumor effect on the viability of liver cancer cells, although not on cancer stem-like cells.

Clinicopathological Significance of Expression of Tspan-1, Jab1 and p27 in Human Hepatocellular Carcinoma

The aim of this study was to investigate the expression of Tspan-1, Jab1 and p27 in human hepatocellular carcinoma (HCC) and their clinicopathological significance. The expression of Tspan-1, Jab1 and p27 was detected in HCC tissues, the tissues around cancer (76 cases), and the normal tissues around the liver hemangiomas (10 cases). The overexpression of Tspan-1 and Jab1 was found in HCC tissues, positively correlated with clinical stage and negatively correlated with survival rate. The expression of p27 was found inversely linked to which of Tspan-1 and Jab1. In conclusion, the expression of Tspan-1, Jab1 and p27 is significantly associated with development of HCC. Overexpression of Tspan-1 and Jab1 suggests poor prognosis but overexpression of p27 may expect good prognosis for patients with HCC.

The Effect of Rosiglitazone on the Cell Proliferation and the Expressions of p27 and Skp2 in Helicobacter pylori Infected Human Gastric Epithelial Cells / 대한소화기학회지

BACKGROUND/AIMS: Ligands for peroxisome proliferator-activated receptor gamma (PPAR gamma), a member of the ligand-activated nuclear receptor superfamily, exhibit anti-tumoral effects and are associated with de novo synthesis of proteins involved in regulating the cell cycle and cell survival/death. Helicobacter pylori (H. pylori) is an etiologic agent for gastric adenocarcinoma, and raises the cell turnover of gastric epithelium. The aim of this study was to investigate the effect of PPAR gamma ligand rosiglitazone on the cell proliferation and the expressions of p27 and Skp2 protein in H. pylori infected gastric epithelial cells. METHODS: We examined the expression of PPAR gamma by Western blot in H. pylori infected AGS human gastric epithelial cells. The effect of rosiglitazone on the survival of H. pylori infected AGS cells was assessed by cell viability assay. After the treatment of rosiglitazone in H. pylori infected AGS cells, the expressions of p27 and Skp2 were assessed by Western blot. RESULTS: The expression of PPAR gamma protein was increased in H. pylori infected AGS cells. Cell growth was inhibited and decreased in dose- and time- dependent manner in H. pylori infected AGS cells treated with rosiglitazone. A decrease in Skp2 expression and a reciprocal increase in p27 expression were found in dose- and time-dependent manner in H. pylori infected AGS cells treated with rosiglitazone. CONCLUSIONS: Rosiglitazone inhibited the growth of H. pylori infected AGS cells. Rosiglitazone attenuated Skp2 expression, thereby promoting p27 accumulation in H. pylori infected human gastric epithelial cells. Further studies will be needed to find the effects of accumulation on cell turnover in H. pylori infection and the role in the H. pylori-associated gastric carcinogenesis.

Effect of p27Kip1 inhibition on proliferation of bovine corneal endothelial cells by RNA interference / 华中科技大学学报（医学）（英德文版）

Three plasmids (pGenesil-P1, pGenesil-P2, pGenesil-P3) with different p27Kip1-shRNA sequences were designed and synthesized. Their effects on the proliferation of bovine corneal endothelial cells (bCEC) were investigated. Plasmid expressing irrelevant shRNA with a random combination was used as negative control (pGenesil-HK). The recombination of four plamids was confirmed by restrictive enzyme digestion and sequence analysis. The expression of mRNA and protein of p27Kip1 was detected by RT-PCR and Western blotting after stable transfection. The expressions of p27Kip1 mRNA and p27Kip1 protein of pGenesil-P1 group, pGenesil-P2 group and pGenesil-P3 group were all lower than those in the pGenesil-HK group and the blank group (non-transfected group). pGenesil-P3 had the strongest inhibitory effect and was selected for the next steps. The proliferation rates of the pGenesil-P3 group, the pGenesil-HK group and the blank group were assessed by MTT. The influence of shRNA-p27Kip1 on bCEC cell cycle was detected by flow cytometry (FCM). Compared with the control groups, the proliferation rate of the pGenesil-P3 group was increased significantly, and the ratio of S-phase also increased. It is concluded that shRNA-p27Kip1 could down-regulate the expression of p27Kip1 effectively and increase the proliferation of bCEC. RNA interference (RNAi) may be an effective means to promote the proliferation of CEC.

TGF-beta1-induced PINCH-1-ILK-alpha-parvin complex formation regulates mesangial cell proliferation and hypertrophy

TGF-beta1-induced glomerular mesangial cell (GMC) injury is a prominent characteristic of renal pathology in several kidney diseases, and a ternary protein complex consisting of PINCH-1, integrin-linked kinase (ILK) and alpha-parvin plays a pivotal role in the regulation of cell behavior such as cell proliferation and hypertrophy. We report here that PINCH-1-ILK-alpha-parvin (PIP) complex regulates the TGF-beta1-induced cell proliferation and hypertrophy in cultured rat GMCs. When GMCs were treated with TGF-beta1 for 1, 2 and 3 days, the PIP complex formation was up-regulated after 1 day, but it was down-regulated on day 2. Cell numbers were significantly elevated on day 2, but dramatically decreased on day 3. In contrast, a significant increase in cellular protein contents was observed 3 days after TGF-beta1-treatment. TGF-beta1 induced early increase of caspase-3 activity. In GMCs incubated with TGF-beta1 for 2 days, cytosolic expression of p27(Kip1) was dramatically reduced, but its nuclear expression was remarkably elevated. A significantly decreased expression of phospho-Akt (Ser 473) was observed in the cells treated with TGF-beta1 for 1 day. TGF-beta1 induced early increase of phospho-p27(Kip1) (Thr 157) expression with subsequent decrease, and similar responses to TGF-beta1 were observed in the p38 phosphorylation (Thr 180/Thr 182). Taken together, TGF-beta1 differently regulates the PIP complex formation of GMCs in an incubation period-dependant fashion. The TGF-beta1-induced up- and down-regulation of the PIP complex formation likely contributes to the pleiotropic effects of TGF-beta1 on mesangial cell proliferation and hypertrophy through cellular localization of p27(Kip1) and alteration of Akt and p38 phosphorylation. TGF-beta1-induced alteration of the PIP complex formation may be importantly implicated in the development and progression of glomerular failure shown in several kidney diseases.

Immunohistochemical evaluation of p27 (kip1) in pleomorphic adenomas and adenoid cystic carcinomas of the minor salivary glands.

BACKGROUND: p27(kip1), a universal cyclin-dependent kinase inhibitor, is a useful marker for predicting clinical aggressiveness with various human tumors. In this study, p27 expression was investigated in pleomorphic adenomas (PAs) and adenoid cystic carcinomas (ACCs) of minor salivary glands to evaluate its utility for differentiation purposes. At the same time, the correlation between p27 and ACC grading was evaluated. MATERIALS AND METHODS: Clinicopathological features of 22 patients (11 ACCs, 11 PAs), including age, sex and size of tumor were obtained from medical records. Immunohistochemical staining with p27(kip1) was performed for each specimen and p27 labelling indices were determined with a computer-assisted image-analyzing system (CAS 200). Pearson's correlation coefficient, Spearman's correlation coefficient, Students t-test, Kruskal-Wallis test and ANOVA were applied for statistical analyses using SPSS 11.5. RESULTS: p27 LIs for all PAs were above 25% whereas for ACCs they were under 25% (except one case). p27 expression (LI and intensity) was significantly lower in ACCs than PAs. The correlation between p27 expression and ACC grading was not significant. CONCLUSION: Overall, these findings suggest that reduced expression of p27 might be correlated with the development of ACC and could be an indicator of malignant behavior.

Expression of Cyclin Dependent Kinase Inhibitors of KIP Family in Gastric Cancer / 대한소화기학회지

BACKGROUND/AIMS: The cyclin-dependent kinase inhibitors (CDKI) including p21, p27, and p57 of the kinase inhibitor protein (KIP) family are negative regulators of cell cycle progression and potentially act as tumor suppressor. Tumor behavior and growth are influenced by the extent of tumor cell proliferation. The aim of this study was to evaluate the expression of KIP family CDKI in gastric cancer tissue, and to examine the relationship between these expression and various clinicopathological parameters including tumor cell proliferation. METHODS: We conducted an immunohistochemical analysis of p21, p27, and p57 expression in 109 gastric cancer tissues. Tumor cell proliferation was assessed by immunohistochemistry with antibody against Ki-67. RESULTS: Negative expression of p21, p27, and p57 was demonstrated in 45.9%, 65.1%, and 57.8% of cancer tissues, respectively. Negative expression of p21 correlated with larger tumor size, poor differentiation, depth of invasion, lymph node metastasis and advanced TNM stage (p=0.048, 0.041, 0.001, 0.005, and 0.001 respectively). Negative expression of p21 correlated with poor survival (p=0.037). Tumors with negative p21 expression had higher Ki-67 expression than those with positive p21 expression (p=0.024). No significant correlation could be observed between status of p27 and p57 expression and various clinicopathological parameters including survival and tumor cell proliferation. CONCLUSIONS: These results suggest that negative expression of p21 may play an important role in carcinogenesis by stimulating tumor cell proliferation, and may help in predicting the prognosis of gastric cancer.

Bis induces growth inhibition and differentiation of HL-60 cells via up-regulation of p27

Bis (Bag-3, CAIR), a Bcl-2-interacting protein, promotes the anti-apoptotic activity of Bcl-2 and increased levels of Bis have been observed in several disease models. The involvement of Bcl-2 and some Bcl-2-binding proteins in differentiation has recently been reported. However, the relevance of Bis to cellular differentiation remains unknown. The findings herein show that Bis expression is up-regulated during the differentiation of HL-60 cells. To investigate the effect of Bis expression on differentiation, we established Bis-overexpressing HL-60 cells (HL-60-bis). HL-60-bis cells have a low nuclear: cytoplasmic ratio and indented nucleus in Wright- Giemsa staining, and an increased expression of CD11b in immunofluorescence study, indicating the promotion of differentiation. The overexpression of Bis also resulted in a retarded cell growth rate, accompanied by the accumulation of HL-60 cells at the G0/G1 phase of the cell cycle, which was sustained during the differentiation process. Western blot analysis revealed that the expression of p27, a representative inducer of cell cycle arrest at the G1 phase, was increased 2.5-fold in HL-60-bis cells compared to HL-60-neo cells. These results suggest that the Bis induced growth inhibition of HL-60 cells promotes G0/G1 phase arrest via up-regulation of p27, which seems to be a prerequisite for differentiation. Further studies will be required to define the exact roles of Bis on cellular differentiation more precisely.