Protein Expression Levels Of Ki67 Research Articles

Chemical composition, cytotoxicity and molecular profiling of Cordia africana Lam. on human breast cancer cell line

Metabolic profiling of the hexane extract and essential oil of Cordia africana Lam., an economically important agroforestry species, was performed using GC-FID and GC-MS. Cytotoxicity was assessed in MCF-7 cancer cells using sulphorhodamine-B assay. Caspase-8, BcL-2 and Ki-67 levels were evaluated using enzyme-linked immunosorbent assay. Forty-one compounds were identified in the hexane extract, meanwhile, eighty compounds were annotated in the essential oil. n-Decane (9.52%), β-sitosterol (8.13%), undecane (6.32%) and palmitaldehyde (5.50 %) were the major compounds identified in the hexane extract, whereas, β-caryophyllene (32.0%), germacrene D (10.12%) and δ-cadinene (7.20%) predominated in the essential oil. The half maximal inhibitory concentrations (IC50) of the extract and oil were 4.55 µg/mL and 12.90 µg/mL, respectively. Caspase-8 activity increased significantly in hexane extract treated cells. Furthermore, BcL-2 and Ki-67 protein expression levels were significantly decreased. Cordia africana Lam exhibit potent cytotoxicity against breast cancer cell line, most likely through apoptosis regulation.

Synergistic effects of bevacizumab in combination with β-elemene on subcutaneous xenografts derived from HCT-116 human colon cancer cells.

BackgroundTo observe the effect of bevacizumab in combination with β-elemene on subcutaneous xenografts established from HCT-116 human colon cancer cells, explore the underlying mechanisms involved, and provide more options for the treatment of advanced colorectal cancer.MethodsMice were randomly divided into four groups: control, β-elemene, bevacizumab and combination treatment. Tumor volume was measured and the tumor inhibition rate and coefficient of drug interaction (CDI) were calculated. The pathological and morphological features of the tumor tissues were observed. Protein expression levels of ki-67, CD31, vascular endothelial growth factor (VEGF) and bcl-2 were measured by immunohistochemistry.ResultsThe tumor volumes in the four groups were 0.991±0.131, 0.833±0.145, 0.563±0.131 and 0.324±0.066 cm3, respectively. The tumor inhibition rates in the β-elemene, bevacizumab and combination groups were 15.9%, 43.2% and 67.3%, respectively. The degree of tumor reduction in the combination group was the most significant (P<0.05), with a CDI of 0.697. Immunohistochemistry showed that the ki-67 proliferation indexes in the four groups were 30.06%±3.37%, 19.79%±3.75%, 27.51%±2.16% and 16.9%±1.09%, the microvessel densities (MVDs) were 45.86±9.28, 31.14±5.58, 27.57±6.11 and 12.14±3.53, the rates of positive VEGF expression were 39.48%±6.72%, 28.86%±3.54%, 25.04%±2.64% and 19.5%±2.68%, and the rates of positive bcl-2 expression were 33.95%±6.38%, 20.11%±9.49%, 24.28%±6.57% and 11.18%±2.72%, respectively. Compared with the control group, the three experimental groups displayed different degrees of reduction in the above indicators (P<0.05), with the combination group exhibiting the lowest values (P<0.05).ConclusionsBevacizumab exerts a synergistic effect with β-elemene in suppressing the growth of tumors derived from HCT-116 cells, and the related mechanisms may include the inhibition of tumor cell proliferation and tumor angiogenesis and the promotion of tumor cell apoptosis.

LncRNA HULC promots HCC growth by downregulating miR-29

Objective: To explore the effects of lncRNA HULC on hepatocellular carcinoma (HCC) growth by down-regulating miR-29. Methods: The expression levels of HULC and miR-29 in HCC tissues and cells were detected by real-time quantitative PCR (RT-qPCR), and the correlation analysis was performed. After HCC cells were transfected with HULC overexpressed plasmid or siRNA, the expressions of miR-29 and its target gene SETDB1 were determinate by RT-qPCR. According to the bioinformatic prediction of the miR-29 binding site in the HULC sequence, the report gene plasmids were constructed. The HCC cells were co-transfected with miR-29 mimics or miR-29 inhibitor, and the HULC targeted regulation of miR-29 was verified by dual luciferase reporter assay. The effect of miR-29 on the HULC-mediated proliferation in HCC cells was detected by cell count kit 8 (CCK-8) experiment. Expression of tumor proliferation antigen Ki-67 was detected by RT-qPCR.The Hep3B cells were inoculated in mice and miR-29 mimics and miR-29 negative control (NC) further injected into the lesions. The tumor volume was observed, and the expressions of tumor proliferation antigen ki-67 in tumor tissues were detected by immunohistochemical staining. Results: The expression of HULC was significantly up-regulated while the expression of miR-29 was significantly down-regulated in HCC tissues and cells (P<0.01). The level of HULC was negatively correlated with miR-29 in tumor tissues (r=-0.754, P<0.01) and HCC cells (r=-0.865, P<0.05). The in vitro experiments showed that, compared with the blank control group, the expression of miR-29 in HULC overexpressed Huh7 cells was significantly reduced, while the mRNA level of miR-29 target gene SETDB1 was increased (P<0.01). The expression of miR-29 was significantly increased in HULC deleted Hep3B cells, while the mRNA expression of SETDB1 was decreased (P<0.01). Double luciferase reporter gene assay showed that miR-29 mimics significantly inhibited the luciferase activity of Hep3B cells transfected with HULC wide type (psi-HULC-WT) plasmid but had no effect on Hep3B cells transfected with mutant plasmid (psi-HULC-Mut). However, the miR-29 inhibitor antagonized the inhibitory effect of miR-29 mimics on luciferase activity of psi-HULC-WT (P<0.01). Cell proliferation experiments showed that, compared with the control group, the proliferation ability of miR-29 mimics overexpressed Huh7 cells was significantly reduced.After 24, 48 and 72 hours of treatment, the proliferation rates of Huh7 cells in the HULC overexpressed group were (43.87±3.82)%, (83.45±7.46)% and (123.34±8.67)%, respectively, significantly higher than (13.45±1.77)%, (23.54±1.37)% and (38.21±2.09)% of control group (P<0.05). After treatment for 48 and 72 hours, the proliferation rates of miR-29 mimics transfected Huh7 cells were (57.10±1.94)% and (73.76±3.46)%, respectively, significantly lower than (83.45±7.46)% and (123.34±8.67)% of control group (P<0.05). After treatment for 48 and 72 hours, the proliferation rates of Huh7 cells transfected with miR-29 mimics and miR-29 inhibitor group were (76.45±3.24)% and (89.37±4.37)%, respectively, significant higher than (57.10%±1.94)% and (73.76±3.46)% of the control group (P<0.05). After 48 h transfection, the expression of Ki-67 in Huh7 transfected with miR-29 mimics was significantly inhibited compared with the control group (P<0.01). However, the expression of Ki-67 mRNA was increased in Huh7 cells transfected with miR-29 inhibitor (P<0.01). The results of in vivo experiments showed that the tumor volumes of the control group, miR-29 mimics group and miR-29 mimics + miR-29 inhibitors group were (504.0±19.6) mm(3), (310.0±24.3) mm(3) and (483.7±21.2) mm(3), respectively. Injection of miR-29 mimics reduced while miR-29 inhibitor promoted tumorigenesis ability of Huh7 in nude mice (P<0.01). The immunohistochemical staining showed that the average optical density values of Ki-67 protein in tumor tissues of the control group, miR-29 mimics group and miR-29 analogue+ miR-29 inhibitor group were 0.65±0.08, 0.36±0.07 and 0.56±0.06, respectively. The expression level of Ki-67 protein in miR-29 mimics group was significantly reduced (P<0.01) while increased in the miR-29 mimics+ miR-29 inhibitor group (P<0.01). Conclusion: LncRNA HULC promotes HCC growth by down-regulating miR-29.

Circular RNA CDR1as acts as a sponge of miR-135b-5p to suppress ovarian cancer progression.

Background and objectives: Ovarian cancer is the most fatal primary malignancy among gynecological cancers. Circular RNAs (circRNAs) play an important role in the development of various cancers, but the functions of circRNAs in ovarian cancer development have not been studied. We aim to explore the function and mechanism of CDR1as in the progression of ovarian cancer and to provide a new target for the diagnosis and treatment of ovarian cancer.Methods: Ovarian cancer cell proliferation was assessed according to proliferating cell nuclear antigen (PCNA) and Ki67 protein expression levels and MTT and CCK8 assays. The migration ability of cells was detected by scratch-wound assays, and the invasion ability of the cells was determined by Transwell® assays. qRT-PCR and Western blotting were used to verify miRNA and protein expression.Results: CDR1as expression in ovarian tissues was significantly lower in ovarian cancer patients than in patients without ovarian cancer. CDR1as overexpression inhibited the proliferation, invasion and migration of ovarian cancer cells. Silencing CDR1as increased the expression of miR-135b-5p and decreased the expression of hypoxia-inducible factor 1-alpha inhibitor (HIF1AN), thus increasing the proliferation capacity of ovarian cancer cells.Conclusions: CDR1as, acting as a sponge of miR-135b-5p, promotes the expression of HIF1AN and therefore plays a role in tumor inhibition.

Efficacy of the Ribvd Regimen in High Risk Mantle Cell Lymphoma Patients As Defined By the Mipic Prognostic Score: Identification of KI67, LDH and Performance Status As Most Important Prognostic Factors (PF). a French Lysa Group Study

BackgroundThe proliferation index (PI), defined by KI67 protein expression has been identified as a key prognostic factor (PF) in mantle cell lymphoma (MCL) (1, 2). A GOELAMS/LYSA study (n = 113 patients) identified a cut point of 26% for KI67 positivity as an independent predictor of overall survival together with LDH levels, B symptoms and ECOG-PS, in MCL (GOELAMS index : GI). (1) Recently, the European MCL network confirmed the independent prognostic power of KI67 protein expression levels to predict OS in MCL (n = 508) and proposed a new score "MIPIc" (KI67cut-off of 30%). (2) While these scores show prognostic impact in the immuno-chemotherapy setting, with or without ASCT and / or maintenance therapy, their predictive power in the setting of targeted therapy remains uncertain.ObjectiveThe aim of this study was to test the predictive power of the MIPIc and GI prognostic indices in a cohort of elderly MCL patients treated by a proteasome-inhibitor-based immunochermotherapy regimen within a prospective phase II trial of the LYSA group (LyMa SA 2010 ; Rituximab, Bendamustine, Velcade and Dexamethasone regimen : RiBVD). (3)Material and methodThe final analysis of the LyMA SA 2010, presented at ASH 2014 (3), showed overall clinical and molecular response rates of 86.5% and 85%. The 24 months estimated OS and PFS was respectively 80% and 70%. (3) In order to assess the prognostic power of KI67 expression levels for OS, all survival data were updated. KI67 staining was performed and reviewed centrally by one pathologist of the LYSA-P, according to the European guidelines. (4) The MIPIc and GI scores were calculated and their impact on survival analyzed (Logrank). In addition, all 6 variables comprising the MIPc and the GI indices were assessed separately by univariate analyzes for prognostic value (these were LDH, ECOG and KI67 that are common to the 2 indices, and Age and WBC for the MIPIc and B Symptoms for GI). Finally a Logrank permitted to define 3 groups of patients with a high statistically impact on survivals with the 3 common variables of MIPIc and GI. ResultsAmong the 74 elderly MCL patients treated in first line by the RiBVD regimen, 59 are alive with a median follow up of 40 months. Estimated OS and PFS at 36 months are respectively 78.4% and 65%. The MIB1 was evaluated on 58 samples for which the MIPIc and GI could be calculated for 57 patients (no LDH value for one patient). MIPIc and GI were not able to define relevant prognostic subgroups for OS (p =0.55 and 0.11). Only the 3 common variables LDH (N vs >N), ECOG (O-1 vs >1) and MIB1 (with a cut-off at 46% corresponding to the fourth quartile of MIB1 expression levels) were individually predictive of OS by univariate analysis (respectively with p=0.0006, p=0.048 and p=0.0031). With these three variables the Logrank test separated three groups that were statistically discriminant for OS and PFS: one group with 0 risk factors n=24 patients, 42%), a second group with one risk factor (n=20 patients, 32%) and the last group with 2 or 3 risk factors (n=13 patients, 23%). Hence the 3 year OS of these 3 groups was respectively 96%, 75% and 30% (p<0.0001). The 3 year PFS was 87.5%, 65% and 8% (p<0.0001)In ConclusionThe proteasome-inhibitor-based immunochemotherapy regimen, RiBVD, induces prolonged survival of "High risk" patients, as defined by this modified MIPIc score. More proliferative disease, defined by a KI67 superior to 46%, combined with a high LDH level and/or a high PS defines a high subgroup of patients under the RiBVD regimen (median PFS and OS of respectively 15 and 10 months).Ref: 1 Gressin R, Haematologica 2010. 2 Hoster E et al, J Clin Oncol 2016. 3 Gressin R et al, ASH Blood 2014. 4 Klapper W, H Hematop 2009. [Display omitted] [Display omitted] DisclosuresCartron:Roche: Consultancy, Honoraria; Celgene: Honoraria; Gilead: Honoraria; Jansen: Honoraria. Dartigeas:Roche: Consultancy; Mundipharma: Other: travel grant. Dupuis:janssen: Honoraria; ABBVIE: Membership on an entity's Board of Directors or advisory committees. Karlin:takeda: Consultancy; Bristol: Consultancy; celgene: Consultancy, Honoraria; janssen-cilag: Consultancy, Honoraria; amgen: Consultancy, Honoraria.

Expression and significance of annexin A2 in patients with gastric adenocarcinoma and the association with E-cadherin.

Annexin A2 is a calcium-dependent phospholipid-binding protein, involved in invasion, angiogenesis and migration in cancer cells. The aims of the present study were to evaluate the expression levels of annexin A2 and E-cadherin in gastric adenocarcinoma (GAC), and to investigate the association between the expression of annexin A2 and that of E-cadherin and Ki67, in addition to various clinicopathological factors. This study included 126 patients that were histopathologically diagnosed with GAC. Tissue samples were acquired by surgical resection, and annexin A2 mRNA expression levels were determined using reverse transcription-quantitative polymerase chain reaction. Annexin A2, E-cadherin and Ki67 protein expression levels were detected using western blot analysis and/or immunohistochemical staining. The expression of annexin A2 mRNA and protein was significantly upregulated in the GAC tissues. Annexin A2 expression was detected in 52/126 cases (41.3%) of gastric cancer (GC), and correlations were identified between annexin A2 expression and Tumor, Node, Metastasis (TNM) stage (P=0.002), lymph node metastasis (P=0.016) and distal metastasis (P=0.005). The positive expression rates of E-cadherin and Ki67 in the tumor tissue of patients with GAC were 27.8% (35/126) and 56.2% (71/126), respectively. A negative correlation was observed between the expression of annexin A2 and E-cadherin (P<0.001). No significant association was detected between the expression levels of annexin A2 and Ki67 (P=0.801). In conclusion, upregulated annexin A2 expression was associated with lymph node metastasis, distal metastasis, advanced TNM stage and E-cadherin expression in patients with GAC. The association between the expression of annexin A2 and that of E-cadherin may indicate an underlying mechanism by which annexin A2 contributes to the metastasis in GC, and thus annexin A2 may represent a potential target for the treatment of GAC.

Salivary duct carcinoma: A clinopathological report of 11 cases.

The aim of the present study was to summarize the clinicopathological and immunohistochemical characteristics of salivary duct carcinoma (SDC) and to evaluate the currently available treatment modalities. Between 2001 and 2011, 11 patients with SDC were diagnosed and treated at the Affiliated Hospital of Stomatology of Nanjing University (Nanjing, Jiangsu, China). The present study retrospectively reviewed the clinicopathological and immunohistochemical data of these 11 patients and the results indicated that the parotid gland was the most commonly affected site, followed by the submandibular gland and the palate. Furthermore, the mean age of onset was 58.8 years and all cases were treated with surgery, with 72.7% receiving post-operative radiation therapy. The range for the follow-up period was 10-89 months and of the 11 patients investigated, only two succumbed to the disease. In addition, the two-year overall survival rate was 75% according to Kaplan-Meier analysis and the mean overall survival time was 72.8 months. In conclusion, the present study determined that the site of the malignancy is the best predictor of survival in patients with the rare salivary malignancy SDC, while age, gender, T stage, N stage, American Joint Committee on Cancer stage, nerve paralysis, post-operative radiation, neck dissection, and protein expression levels of Ki-67, androgen receptor and human epidermal growth factor-2/neu are less influential factors.

Identifying Ki-67 specific miRNA–mRNA interactions in malignant astrocytomas

Background: Ki-67 is an excellent indicator of glioma cell growth. However, limited information is available regarding the mechanisms underlying abnormal expression of Ki-67 in glioma tissue. The aim of this study is to identify Ki-67 specific miRNA–mRNA interactions on basis of miRNA and mRNA expression profilings. Methods: We performed a large-scale miRNA (n=829) and mRNA (n=29,421) expression profiling in primary glioblastoma multiforme (pGBM) and anaplastic astrocytoma (AA) tissues (with an aim to investigate Ki-67 related miRNAs and mRNAs). From target prediction databases, the targeting relationships between Ki-67 specific miRNAs and mRNAs were established, and functions of these mRNAs were analyzed by DAVID. The functional verifications of the candidate miRNA were also performed in LN229 cell line. Results: High expression level of Ki-67 protein predicted a shorter survival time for patients with AA. Integrated analysis of profiling data from pGBM and AA revealed 4 Ki-67 positively and 5 negatively correlated miRNAs, along with the top 12 Ki-67 positively and 2 negatively correlated mRNAs. By means of target prediction, we found that the target mRNAs employed by miR-218 were the most significant among Ki-67 specific mRNAs. Up-regulation of miR-218 was further demonstrated to reduce Ki-67 expression, promote apoptosis, and induce G0/G1 phase cell cycle arrest in LN229 cells. Conclusions: Ki-67 protein may be regulated by specific miRNA–mRNA interactions which may contribute to the proliferation of glioma cells.

Inhibition of Tumor Growth in Vitro by a Combination of Extracts from Rosa Roxburghii Tratt and Fagopyrum Cymosum

Traditional Chinese herbal medicines have a very long history. Rosa roxburghii Tratt and Fagopyrum cymosum are two examples of plants which are reputed to have benefits in improving immune responses, enhancing digestive ability and demonstrating anti-aging effects. Some evidence indicates that herbal medicine soups containing extracts from the two in combination have efficacy in treating malignant tumors. However, the underlying mechanisms are far from well understood. The present study was therefore undertaken to evaluate anticancer effects and explore molecular mechanisms in vitro. Proliferation and apoptosis were assessed with three carcinoma cell lines (human esophageal squamous carcinoma CaEs-17, human gastric carcinoma SGC-7901 and pulmonary carcinoma A549) by MTT assay and flow cytometry, respectively, after exposure to extract from Rosa roxburghii Tratt (CL) and extract from Fagopyrum cymosum (FR). IC30 of CL and FR were obtained by MTT assay. Tumor cells were divided into four groups: control with no exposure to CL or FR; CL with IC30 CL; FR with IC30 FR; CL+FR group with 1/2 (IC30 CL+IC30 FR). RT-PCR and Western blot analysis were used to detect the expression of Ki-67, Bax and Bcl-2 at mRNA and protein levels. Compared with the CL or FR groups, the combination of CL+FR showed significant inhibition of cell growth and increase in apoptosis; the mRNA and protein expression levels of Ki-67 and Bcl-2 in CL+FR group were all greatly decreased, while the expression of Bax was markedly increased. These results indicate that the synergistic antitumor effects of combination of CL and FR are related to inhibition of proliferation and induction of apoptosis.

Correlation of IDH1 Mutation with Clinicopathologic Factors and Prognosis in Primary Glioblastoma: A Report of 118 Patients from China

It has been reported that IDH1 (IDH1R132) mutation was a frequent genomic alteration in grade II and grade III glial tumors but rare in primary glioblastoma (pGBM). To elucidate the frequency of IDH1 mutation and its clinical significance in Chinese patients with pGBM, one hundred eighteen pGBMs were assessed by pyro-sequencing for IDH1 mutation status, and the results were correlated with clinical characteristics and molecular pathological factors. IDH1 mutations were detected in 19/118 pGBM cases (16.1%). Younger age, methylated MGMT promoter, high expression of mutant P53 protein, low expression of Ki-67 or EGFR protein were significantly correlated with IDH1 mutation status. Most notably, we identified pGBM cases with IDH1 mutation were mainly involved in the frontal lobe when compared with those with wild-type IDH1. In addition, Kaplan-Meier survival analysis revealed a highly significant association between IDH1 mutation and a better clinical outcome (p = 0.026 for progression-free survival; p = 0.029 for overall survival). However, in our further multivariable regression analysis, the independent prognostic effect of IDH1 mutation is limited when considering age, preoperative KPS score, extent of resection, TMZ chemotherapy, and Ki-67 protein expression levels, which might narrow its prognostic power in Chinese population in the future.

Expression of Ang-1, Ang-2 and Tie-2 receptor mRNAs and their implications in hemangioma by RT-PCR

Objective To detect the expression level of Ang-1, Ang -2 and Tie-2 receptor mRNAs in the hemangioma tissuses and to explore the effects of Ang-1, Ang-2, and Tie-2 receptor on the angio-genesis in the hemangioma. Methods By use of semiquantinative reverse transcription polymerase chain reaction, we detected the expression level of Ang-1 mRNA, Ang-2 mRNA and Tie-2 mRNA in 30 cases of hemangioma (17 specimens of proliferating hemangioma, and 13 involuting hemangioma )together with 10 cases of normal skin as control, and the expression level of Ki-67 protein was also detected by an im-munohistochemica method. Results The expression of Ang-2 mRNA and Tie-2 mRNA in the prolifera-ting hemangiomas was higher than that in involuting hemangiomas (P<0.01) . The expression of Ang-1 mRNA in hemangiomas was negative. Conclusion The unbalance of Ang-Tie-2 system is probably impor-tant for the pathogenesis and development in hemangiomas. Key words: Hemangiomas; Angiopoietin; Tie-2 reeeptor; Cell proliferation associated pro-tein Ki-67

Overexpression of hMSH2 and hMLH1 protein in certain gastric cancers and their surrounding mucosae

Mismatch repair (MMR) deficiency is closely related to oncogenesis, which is usually accompanied with the loss of expression of hMSH2 and/or hMLH1. These two proteins are detected in many gastric cancers (GCs), and even their overexpression have been reported in certain other cancers. We studied the protein expression levels of MMR (hMSH2 and hMLH1), PCNA and Ki67 in the cancers and surrounding mucosae (SMs) collected from the patients with GC and gastric mucosa samples from non-cancer patients (NCMs), using immunohistochemistry. Our results demonstrated that the positive MMR protein expression levels were 69.1% (132/191), 33.1% (44/133) and 7.1% (3/42) in GCs, SMs and NCMs, respectively (P<0.001); the positive PCNA protein expression levels were 92.1% (176/191), 75.9% (101/133) and 23.8% (10/42), respectively (P<0.001); the positive Ki67 protein expression levels were 79.1% (68/86), 29.2% (21/72) and 45.2% (19/42), respectively (P<0.001). In addition, the MMR protein expression significantly correlated to the level of PCNA protein expression (rs=0.170, P=0.019), but not to the level of Ki67 protein expression in GCs. Notably, the overexpression of MMR protein was not correlated to either PCNA or Ki67 protein expression in SMs and NCMs. These results support the evidence that MMR protein expression may increase prior to gastric cancer occurrence, and in a view of early diagnosis, the detection of MMR protein by IHC may be helpful as a marker in early prediction of gastric cancer.

Nestin small interfering RNA (siRNA) reduces cell growth in cultured astrocytoma cells

Nestin is an embryonic intermediate filament that transiently expressed in the neural stem/progenitor cells in the developing central nervous system (CNS). Growing evidence has shown that abundant expression of nestin also occurs in both pathological glial-derived tumor cells and reactive astrocytes in various CNS injuries, implying that nestin may play a crucial role in cell growth or proliferation of astrocyte-derived tumor cells. In the present study, we have investigated the possible role of nestin expression in cell growth or survival of CNS tumor cells by using novel small interfering RNA (siRNA) method in cell culture of rat astrocytoma C6 cell line. The nestin expression and cell growth of the cultured astrocytoma cells were examined after nestin siRNA duplex was delivered by cell transfection for 6 h and cell culture was maintained for 48 h. It revealed an effective suppression influence of nestin siRNA on cell growth of cultured astrocytoma cells in a dose-dependent manner. Quantitative data analysis showed that the doses of nestin siRNA at 30–120 nM significantly decreased both cell numbers and expression levels of nestin mRNA and protein. The nestin siRNA also suppressed expression of cellular glial fibrillary acid protein but showed no obvious influence on expression level of Ki-67 protein (a cell proliferation marker). This study has provided in vitro evidence that nestin siRNA can effectively block nestin expression and reduce cell growth of the cultured C6 astrocytoma cells, strongly suggesting that nestin siRNA-induced suppression of tumor cell growth may provide a potential novel clinical therapy against CNS astroglioma events.

Expression Patterns of Ki-67 and Telomerase Activity in Middle Ear Cholesteatoma

Keratinocytes in cholesteatoma demonstrate uncoordinated hyperproliferation, migration, and invasion properties. There is a controversy regarding the impact of Ki-67 and telomerase activities on cellular proliferation in cholesteatoma. We studied expression of Ki-67 protein and telomerase activity in cholesteatoma and its relationship with clinical findings. The expression level of Ki-67 protein was examined by immunohistochemical analysis of 51 cholesteatomas and 6 skin tissues obtained from patients during ear surgery. Telomerase activity was determined in 23 samples of cholesteatomas and 6 skin samples by polymerase chain reaction-based telomeric-repeat amplification protocol assay. The presence of Ki-67 protein was observed in 21 (41.2%) of 51 samples of acquired cholesteatoma. The average Ki-67 labeling index in the cholesteatoma group was 28.9 +/- 9.2 and was higher than that in the skin group (18.2 +/- 6.1). Telomerase activity was detected in 2 (8.7%) of 23 samples of cholesteatoma (21 of them were Ki-67 staining positive and 2, negative) and in 3 (50%) of 6 of control skin samples (p < 0.05). This study showed increased expression of Ki-67 in cholesteatoma, whereas there was no significant difference in rate of Ki-67 positive staining between skin and cholesteatoma (p = 0.066). Telomerase activation is a rare event in cholesteatoma. We assume that the absence of telomerase may lead to generation dysfunctional telomeres what in turn may impair the proliferative capacity of cholesteatoma.