microRNA-3129 promotes cell proliferation in gastric cancer cell line SGC7901 via positive regulation of pRb

Several microRNAs (miRNAs) have been reported as oncogenes or tumor suppressors in many cancers, including gastric cancer (GC). However, the role and molecular mechanism of miR-3129 in GC is largely unknown. We aimed to explore the function and the underlying molecular mechanism of miR-3129 in GC. Cancer tissues and corresponding adjacent tissues were collected from 50 patients with GC, and the expression of miR-3129 was detected by RT-qPCR. The expression of miR-3129 and pRb in human GC cell line SCG7091 was altered by transient transfection. Thereafter, MTT and flow cytometry assays were used to analyze cell viability and cell cycle. The expression of cyclin E, CDK2, CDK2 inhibitors (p16 and 21), and pRb were detected by RT-qPCR and western blot. A significant up-regulation of miR-3129 was observed in GC tissues compared to adjacent tissues. Overexpression of miR-3129 significantly improved cell viability after 4 days of post-transfection. Flow cytometry assay results showed that the miR-3129 overexpression arrested more SGC7901 cells at S phase. Moreover, overexpression of miR-3129 down-regulated the expression of CDK2 inhibitors while it up-regulated the expression levels of cyclin E, CDK2, and pRb. Interestingly, we found that pRb inhibition reversed the effect of miR-3129 inhibitor on cell proliferation in SGC7901 cells, increased cell viability, reduced cells at G0/1 phase, and modulated the expression of proliferation-related factors. Our results revealed that miR-3129 functioned as an oncogene through positive regulation of pRb and may prove to be a promising option for molecular therapy of GC.

Genetic perspective of retinoblastoma: From present to future.

Retinoblastoma (RB) is the most common malignant intraocular tumor in children. In the last decade, basic research has led to a better understanding of events after two hits in RB susceptibility gene (RB1), molecular mechanism of tumor growth, the cell of origin of RB, etc. This would pave way to identify biomarkers and molecular targeted therapy for better treatment option in the future. Furthermore, improvement in molecular techniques has led to enhanced diagnostic methods for early diagnosis, genetic counseling, and prevention of the disease. This review will help to understand the essence of basic research work conducted in recent times and its implication in the management of RB in the future.

Ethanol extract of Kalopanax septemlobus leaf inhibits HepG2 human hepatocellular carcinoma cell proliferation via inducing cell cycle arrest at G1 phase

OBJECTIVE@#To investigate the effects of an ethanol extract of Kalopanax septemlobus (Thunb.) Koidz. leaf (EEKS) on cell proliferation in human hepatocellular carcinoma cells and its mechanisms of action.@*METHODS@#Cells were treated with EEKS and subsequently analyzed for cell proliferation and flow cytometry analysis. Expressions of cell cycle regulators were determined by reverse transcriptase polymerase chain reaction analysis and Western blotting, and activation of cyclin-associated kinases studied using kinase assays.@*RESULTS@#The EEKS suppressed cell proliferation in both HepG2 and Hep3B cells, but showed a more sensitive anti-proliferative activity in HepG2 cells. Flow cytometry analysis revealed an association between the growth inhibitory effect of EEKS and with G1 phase cell cycle arrest in HepG2 cells, along with the dephosphorylation of retinoblastoma protein (pRB) and enhanced binding of pRB with the E2F transcription factor family proteins. Treatment with EEKS also increased the expression of cyclin-dependent kinase (CDK) inhibitors, such as p21WAF1/CIP1 and p27KIP1, without any noticeable changes in G1 cyclins and CDKs (except for a slight decrease in CDK4). Treatment of HepG2 cells with EEKS also increased the binding of p21 and p27 with CDK4 and CDK6, which was paralleled by a marked decrease in the cyclin D- and cyclin E-associated kinase activities.@*CONCLUSIONS@#Overall, our findings suggest that EEKS may be an effective treatment for liver cancer through suppression of cancer cell proliferation via G1 cell cycle arrest. Further studies are required to identify the active compounds in EEKS.

Ethanol extract of Kalopanax septemlobus leaf inhibits HepG2 human hepatocellular carcinoma cell proliferation via inducing cell cycle arrest at G

Objective: To investigate the effects of an ethanol extract of Kalopanax septemlobus (Thunb.) Koidz. leaf (EEKS) on cell proliferation in human hepatocellular carcinoma cells and its mechanisms of action. Methods: Cells were treated with EEKS and subsequently analyzed for cell proliferation and flow cytometry analysis. Expressions of cell cycle regulators were determined by reverse transcriptase polymerase chain reaction analysis and Western blotting, and activation of cyclin-associated kinases studied using kinase assays. Results: The EEKS suppressed cell proliferation in both HepG2 and Hep3B cells, but showed a more sensitive anti-proliferative activity in HepG2 cells. Flow cytometry analysis revealed an association between the growth inhibitory effect of EEKS and with G

Fucoidan induces G1 arrest of the cell cycle in EJ human bladder cancer cells through down-regulation of pRB phosphorylation

AbstractFucoidan, a sulfated polysaccharide found in marine algae and brown seaweeds, has been shown to inhibit the in vitro growth of human cancer cells. This study was conducted in cultured human bladder cancer EJ cells to elucidate the possible mechanisms by which fucoidan exerts its anti-proliferative activity, which until now has remained poorly understood. Fucoidan treatment of EJ cells resulted in dose-dependent inhibition of cell growth and induced apoptotic cell death. Flow cytometric analysis revealed that fucoidan led to G1 arrest in cell cycle progression. It was associated with down-regulation of cyclin D1, cyclin E, and cyclin-dependent-kinases (Cdks) in a concentration-dependent manner, without any change in Cdk inhibitors, such as p21 and p27. Furthermore, dephosphorylation of retinoblastoma protein (pRB) by this compound was associated with enhanced binding of pRB with the transcription factors E2F-1 and E2F-4. Overall, our results demonstrate that fucoidan possesses anticancer activity potential against bladder cancer cells by inhibiting pRB phosphorylation.

Expression and clinical significances of progesterone receptor isoforms A and B in ovarian se-rous cystadenocarcinoma / 临床与实验病理学杂志

Purpose To explore the effects of progesterone receptor isoforms A and B ( PR-A,PR-B) on carcinogenesis and progres-sion of ovarian serous cystadenocarcinoma ( OSC) . Methods The expressions of PR-A and PR-B in 52 cases of OSC, 22 cases of o-varian borderline serous cystadenoma ( OBSC) , 22 cases of umbrella of normal fallopian ( UNF) were detected by immunohistochmical Elivision technique. Results The expression of PR-A in OSCs, OBSCs and UNFs were 94. 5%, 94. 5%, and 68. 38%, respective-ly, with there were statistical significance among three groups (P<0. 05). The expression of PR-B in OSCs, OBSCs and UNFs were 100%, 77. 27%, and 40. 38%, respectively, with there were statistical significance among three groups (P<0. 05). The difference of PR-A/PR-B ratio in OSCs, OBSCs and UNFs was statistical significance ( P<0. 05 ) . The expressions of PR-A and PR-B in OSCs were lower, there were statistical significance between the clinical stageⅠ+Ⅱ andⅢ+Ⅳ (P<0. 05), and histological gradeⅠandⅡ. The difference of PR-A/PR-B ratio between the histological gradeⅠandⅡin OSC was statistical significance. There was statistical significance of PR-B between OSCs with lymph metastasis and without lymph metastasis (P<0. 05). Expression of PR-A and PR-B in OSC was positive correlation (P<0. 05). Conclusion With the carcinogenesis and progression of OSC, the expressions of PR-A and PR-B gradually declined, and the downregulation of PR-B is more obvious, may be an important biological sign of malignant transfor-mation in ovarian tissue. The increasing ratio of PR-A to PR-B in OSC may indicate poor differentiation. The relatively higher expres-sion of PR-B may inhibit the lymph metastasis in OSC.

Immortalization of human fallopian tube epithelial cells / 中国癌症杂志

10.3969/j.issn.1007-3969.2013.04.00X

Sodium butyrate modulates pRb phosphorylation and induces cell death in human vestibular schwannomas in vitro.

In the present study, effect of Na-Bu on the pRb phosphorylation was analysed in the primary cultures of 12 VS tumors. Primary cultures of VS tumors were established from the fresh tumor tissues removed surgically and were treated with Na-Bu. Na-Bu treatment for 48 h led to morphological changes and apoptotic cell death in VS tumor cells. Na-Bu treatment decreased level of total pRb and phosphorylated form of pRb and caused specific dephosphorylation at Ser 249/Thr 252 and Ser 567. In the untreated and Na-Bu treated cells (when present), pRb was localised in the nucleus. Moreover, in Na-Bu treated cells the nucleus appeared highly condensed as compared to untreated cells. Results of the present study indicated that Na-Bu treatment modulated pRb phosphorylation status and caused apoptotic cell death in VS tumors.

Expression of pRb, p53, p16 and Cyclin D1 and Their Clinical Implications in Urothelial Carcinoma

The aim of this study was to assess immunohistochemical expression of p53, pRb, p16, and cyclin D1, alone or in combination, as prognostic indicators and to investigate their correlation with clinocopathologic features of urothelial carcinoma. Immunohistochemical staining for p53, pRb, p16, and cyclin D1 was performed on a tissue microarray from 103 patients with urothelial carcinoma who underwent radical cystectomy. Of the patient samples analyzed, 36 (35%), 61 (59%), 47 (46%) and 30 (29%) had altered expression of p53, pRb, p16, and cyclin D1, respectively. Abnormal expression of p53 and pRb correlated with depth of invasion (P=0.040 and P=0.044, respectively). Cyclin D1 expression was associated with tumor stage and recurrence (P=0.017 and P=0.036, respectively). Altered pRb was significantly correlated with overall survival (P=0.040). According to the expression pattern of pRb and p53, p53/pRb (altered/normal) had worse survival than p53/pRb (normal/altered) (P=0.022). Alteration of all markers had worse survival than all normal (P=0.029). As determined by multivariate analysis, tumor stage, lymph node metastasis and the combined expression of p53 and pRb are independent prognostic factors. In conclusion, immunohistochemical evaluation of cell cycle regulators, especially the p53/pRb combination, might be useful in planning appropriate treatment strategies.

Expression Profiles of Retinoblastoma Protein and p27Kip1 According to HER2 Amplification Status in Primary Breast Cancer / 한국유방암학회지

PURPOSE: Human epidermal growth factor receptor-2 (HER-2)/neu amplification affects the cell proliferation through the modulation of multiple G1 cell cycle regulators in breast tumor cells. We performed this study to investigate whether retinoblastoma protein (pRB) and p27Kip1 were differently expressed according to the HER2 amplification status in human breast cancer. METHODS: HER2 amplification was assayed by fluorescence in situ hybridization and the expression of cell cycle regulators were assayed by immunohistochemistry on 153 consecutive invasive breast cancers. The proliferative activity of breast cancer was analyzed according to the HER2 amplification and cell cycle protein expression status. RESULTS: HER2 amplification was observed in 39 (25.5%) of 153 breast cancers. In the HER2 amplified breast cancers, the pRB expression was significantly increased (p=0.011) whereas there was no significant relationship between HER2 amplification and p27Kip1 expression. There was an inverse correlation between pRB expression and Ki-67 labeling index in the HER2 amplified breast cancers (p=0.036). In contrast, Ki67 labeling index was significantly decreased as p27Kip1 expression increased in HER2 non-amplified breast cancers (p=0.028). In HER2 non-amplified breast cancers, we could not observe any association between the pRB expression and Ki67 labeling index. CONCLUSION: The proliferation of the breast cancers was associated with pRB expression in HER2 amplified tumors whereas it was associated with p27Kip1 expression in HER2 non-amplified tumors. The results of the current study indicate that the cell proliferative activity of the breast cancer is under different growth signal pathways according to HER2 amplification status.

Influence of RNA Interference mediated cyclinD1 Gene Silencing on The Proliferation and G1 Phase Regulators of Fibroblasts Derived From Keloid / 生物化学与生物物理进展

In order to investigate the effect of sequence-specific small interfering RNA on suppressing cyclin D1 expression and proliferation and cell cycle and expression of G1 phase regulators of fibroblasts derived from keloid, the plasmid expression vector of siRNA targeted against cyclin D1 was constructed and transfected into fibroblasts with LipofectamineTM 2000. The changes of cyclin D1 expression were detected by fluorescent quantitative PCR(FQ-PCR), semi-quantitative RT-PCR. The effect of sequence- specific small interfering RNA in suppressing the proliferation of fibroblasts was detected by MTT assay. Flow cytometry were used for evaluation ofceU cycle. The expression of cyclin D1, CDK4, pRb and P16 was detected by immunohistochemical method. The results showed that: (1) The sequence- specific siRNA effectively suppressed cyclin D1 expression at both mRNA levels with inhibition rate of 63.68% and 92.83% (P<0.01). (2) Significantly inhibited the proliferation of fibroblasts, and changed cell cycle in percentage of G0/G1 phase cells was increased compared with the controls groups in fibroblasts(P < 0.05). (3) 72 h after transfection, the expression of cyclin D1, CDK4 and pRb decreased, and the expression of P16 increased. It can be concluded that the plasmid expression vector for the RNAi against cyclin D1 constructed in the study can effectively and specifically suppress cyclin D1 expression, and progression of G1/S is effected by G1 phase related regulatory protein, and suppresses proliferation of fibroblasts derived fiom keloid.

MDM2, p53 and pRb Expression Prior to Definitive Chemoradiotherapy in Esophageal Carcinoma / 대한방사선종양학회지

PURPOSE: This study evaluated the pretreatment expression patterns of MDM2, p53, and pRb proteins to determine if the expression patterns could predict the outcome of concurrent chemoradiotherapy (CCRT) for esophageal squamous cell carcinoma and aid in the decisions for the selection of treatment modalities. MATERIALS AND METHODS: Fifty-one patients that were treated with definitive chemoradiotherapy for stage I~IVa esophageal squamous cell carcinoma were selected for this study. Radiotherapy was administered with daily 1.8~2 Gy fractions up to a median dose of 54 Gy for primary tumors, and with four cycles of cisplatin/5- fluorouracil chemotherapy that was administered every 4 weeks, the first two cycles of which were administered concurrently with radiotherapy. Expression of MDM2, p53, and pRb was investigated by immunohistochemical analysis using pretreatment biopsy specimens. RESULTS: MDM2, p53, and pRb were detected with high immunoreactivity in 19.6%, 27.5%, and 66.7% of the patients, respectively. However, there was no significant correlation between expression of these factors and clinical outcome. By the use of multivariate analysis with nine covariates-age, tumor location, tumor length, stage, pathological response, clinical response, MDM2 expression, p53 expression, and pRb expression, only pathological response and stage were significant factors for cause-specific survival. CONCLUSION: Expression of MDM2, p53, and pRb was not found to be clinically significant for predicting outcomes after CCRT in this study. Further studies with a larger patient population and longer follow-up periods are needed to re-evaluate the expression pattern and to identify new predictors for CCRT response.

Relationship between p16(INK4a), pRb and high risk HPV infection and recurrence / 대한산부인과학회지

OBJECTIVE: The purpose of this study was to identify the abnormal expressions of p16(INK4a) and pRb in cervical intraepithelial neoplasia (CIN), and then to determine the relationship between the levels of p16(INK4a) and pRb and high risk HPV infection and recurrence. METHODS: The study group was composed of 265 formalin-fixed, paraffin-embedded tissue array sections of the uterine cervix collected from women who had underwent biopsy, conization or hysterectomy at our hospital from January 2001 to December 2003. Immunohistochemical stainings for p16(INK4a) and pRb were performed and the association of pRb and p16(INK4a) expressions with clinical features was analyzed retrospectively. RESULTS: There was positive correlation between p16(INK4a) expression rate and grade of cervical lesion. Meanwhile, there was reverse correlation between pRb expression rate and grade of cervical lesion. The expression rate of p16(INK4a) was higher (33%) in CIN I with high risk HPV infection, than in CIN I without high risk HPV infection (19%). In all CIN lesions, the mean expression rate of p16(INK4a) was lower in recurred group than in those which did not recur. In CIN II and CIN III, the mean expression rate of pRb was higher in recurred group than in those which did not recur. CONCLUSION: With increasing CIN grade, abnormal expression of p16(INK4a) was increased, but pRb expression was decreased. Relatively decreased p16(INK4a) expressions and increased pRb expressions significantly cooperate to predict a recurrence of the CIN lesions.

Estudo da detecção do DNA do papiloma vírus humano (HPV) e da expressão imuno-histoquímica de proteína do ciclo celular no carcinoma epidermóide oral / Study of DNA detection of human papillomavirus (HPV) and immunohistochemical expression of cell cycle protein in oral squamous cell carcinoma

O carcinoma epidermóide oral é a neoplasia maligna mais freqüente da cavidade oral e o papilomavírus humano (HPV) parece ter um relevante papel na indução desta lesão. Neste trabalho investigou-se o DNA do HPV e tipos virais em 90 casos de carcinoma epidermóide oral (CEO). Realizou-se também uma análise comparativa entre os grupos de CEO com DNA do HPV e sem o DNA do vírus, empregando-se os marcadores do ciclo celular p2l e pRb, a fim de estabelecer possível correlação entre a expressão imuno-histoquímica dessas proteínas e a infecção pelo HPV. O DNA foi extraído de tecido emblocado em parafina e amplificado por PCR (reação em cadeia da polimerase) com um par de primers designados PC03+ e PC04+ para um fragmento do gene da ~-globina humana. Posteriormente, realizou-se PCR para detecção do DNA de HPV utilizando-se um par de primers genéricos designados GP5+ e GP6+. A tipagem viral foi realizada pela hibridização dot blot. No método imuno-histoquímico utilizou-se a técnica da streptavidina-biotina com um painel de anticorpos monoclonais para as proteínas p2l e pRb. Dos 88 casos positivos para o gene da ~-globina humana, em 26 (29,5%) foi detectado o DNA do HPV. Não houve associação significativa entre o HPV e as variáveis idade e sexo dos pacientes e localização anatõmica da lesão. O tipo viral prevalente foi o HPV 18 (80,8%). Quanto à análise imuno-histoquímica, foi observada associação estatisticamente significativa entre a presença do HPV e a expressão imuno histoquímica de pRb (p=0,044), entretanto, não houve qualquer diferença estatisticamente significativa entre a expressão da proteína p2l e a presença do vírus (p =0,416). Pôde-se concluir que o baixo percentual de detecção do DNA do HPV no carcinoma epidermóide oral no presente trabalho, sugere uma possível participação do HPV no desenvolvimento e progressão de apenas um subgrupo dessas lesões.

Oral squamous cell carcinoma (OSCC) is the most common malignancy in oral cavity and human papillomavirus (HPV) may have an important role in its development. The aim of this experiment was to investigate the HPV DNA and viral types in 90 cases of OSCC. Moreover, a comparative analysis between the cases of OSSC with and without HPV DNA was performed by using cell cycle markers p21 and pRb in order to detect a possible correlation of these proteins and HPV infection. DNA was extracted from paraffin embedded tissue and amplified by PCR (polymerase chain reaction) with primers PCO3+ e PCO4+ for a fragment of human β-globin gene. After this procedure, PCR for HPV DNA detection was realized using a pair of generic primers GP5+ e GP6+. Immunohistochemical study was performed by streptoavidin-biotin technique and antibodies against p21 and pRb proteins were employed. Eighty-eight cases were positive for human β-globin gene and HPV DNA was found in 26 (29.5%) of then. It could not be detected significant correlation between HPV and age, sex and anatomical sites of the lesion. The most prevalent viral type was HPV 18 (80.8%). Regarding the immunohistochemical analysis, it was detected significant association between HPV presence and pRb immunoexpression (p=0,044), nevertheless, the same was not observed in relation to p21 protein (p =0,416). It can be concluded that the low detection of HPV DNA in OSCC by the present experiment suggests a possible role of the virus in the development and progression in just a subset of this disease.

Perspectivas en la genómica del retinoblastoma: Implicaciones del gen supresor de tumor RB1 / Genomic retinoblastoma perspectives: Implications of supressor gene of tumor RB1

In order to define the molecular and cellular bases of the development of retinoblastomas it is necessary to know its etiology, and to apply the advances in genome technology to this kind of neoplasia. Retinoblastomas are childhood tumors of the eye with an average incidence of one case in every 15,000-20,000 live births, which occur in sporadic and hereditary forms. The sporadic form appears regularly as a unilateral tumor, while in the familial form of the disease, tumors may be unilateral and bilateral. This neoplasia is characterized by leukocoria, strabism, and heterochromia. The retinoblastoma gene (RBl) is a molecular marker of retinoblastoma tumors. This gene is located in chromosome 13q14.2 and encodes a nuclear phosphoprotein (pRB) of 110 KDa, which plays a major role in cell proliferation control through cell cycle-regulated phosphorylation/dephosphorylation cycles of this protein. The RBl gene is mainly affected by point mutations, which occur most frequently in exons 3, 8, 18 and 20. At the end of the last century, DNA technology has improved notably, allowing for its application to the study of a vast array of diseases. The aim of this work is to show the molecular aspects involved in retinoblastoma which are currently deciphering; this is possible thanks to new technology platforms that have been developed. This will allow us in a near future, to offer tests for the early diagnoses, prognoses, and the determination of individual predisposition towards this neoplasia.

El retinoblastoma es una neoplasia embrionaria que se manifiesta en dos formas: esporádica (no heredada) o familiar (heredada). En los casos esporádicos el tumor es unilateral y en la forma familiar puede presentarse de manera unilateral o bilateral. Esta neoplasia tiene una incidencia promedio de 1/15,000 nacidos vivos, presentando signos y síntomas que incluyen leucocoria, estrabismo, midriasis unilateral y heterocromía. El gen que predispone al desarrollo de retinoblastoma es RBl y se localiza en el cromosoma 13 en la región ql4.2. El gen RBl codifica para una fosfoproteína nuclear que participa de manera importante en la regulación del ciclo celular. De acuerdo con la hipótesis de Knudson, para que se desarrolle la neoplasia se deben presentar dos mutaciones en el gen RBl. Las mutaciones puntuales son las que más frecuentemente se presentan en el gen RBl; la mayoría de los estudios indican que los exones 3, 8, 18, 19 y 20 son las regiones de mutación preferencial. En la áltima década ha habido un gran avance en la tecnología del DNA, lo cual hace posible su aplicación en diferentes enfermedades. Estas herramientas moleculares podrían ser de gran utilidad en el diagnóstico o conocimiento de la predisposición a desarrollar un retinoblastoma. Entre estas valiosas herramientas se cuenta con la hibridación fluorescente realizada in situ, hibridación genómica comparativa, las microhileras y por áltimo la identificación de polimorfismos de un sólo nucleótido. En conclusión, actualmente se están descifrando los aspectos moleculares que están relacionados con el retinoblastoma, gracias a la aplicación de nuevas plataformas tecnológicas. Esto permitirá en un futuro próximo ofrecer pruebas para un diagnóstico temprano o para conocer el pronóstico y la predisposición de individuos a desarrollar esta patología. Con el fin de entender las bases celulares y moleculares del desarrollo del retinoblastoma, el objetivo del presente trabajo es mostrar el estado del arte del conocimiento de esta neoplasia, así como su origen y los avances en la genómica aplicada al retinoblastoma.

Degradation of the Retinoblastoma Tumor Suppressor Protein by the Human Papillomavirus-16 E7 Variants

Human papillomavirus type 16 (HPV-16) plays an etiological role in benign and malignant epithelial tumors. A critical event in HPV transformation of human cells is the inactivation of retinoblastoma protein (pRB) by the E7 protein. The metabolic half-life of pRB is decreased in cells that express high-risk HPV E7 proteins. The present study investigated the frequency of HPV-16 E7 variants in Korean women and compared the pRB degradation activity of E7 variant proteins. Of the 40 HPV-positive specimens from a total of 91 tissue specimens, 21 HPV-16 positive specimens were studied by sequencing analysis to determine the variation of E7 gene. The most frequent E7 variant was N29S (57%). The HPV-16 E7 variant was more prevalent in invasive cervical cancer tissue specimens than in those from low grade clinical stage. The degradation of pRB in HaCaT cells by HPV-16 E7 variant proteins was investigated by western blot analysis. There was no significant difference in pRB degradation activity between the HPV-16 E7 prototype protein and E7 variant proteins. The pRB degradation activity did not differ among HPV-16 E7 variants. These results suggest that the E7-induced degradation of pRB is important in cervical tumorigenesis; however, there was no relation between the pRB degradation activity and the variations in HPV-16 E7 protein among Korean women.

Expression of p14(ARF), p16(INK4a), p53, pRb in Gastric Cancer

PURPOSE: In this study, the level of expression of p14(ARF), p16(INK4a), p53 and pRb was immunohistochemically examined according to the stage of gastric cancer, lymph node metastasis, cell differentiation and Lauren's classification. The effect on survival rate and the associations between the components were examined as well. METHODS: One hundred and fourteen patients who underwent surgery for gastric cancer were studied retrospectively using their paraffin embedded tissue and medical records. Using antibodies of p14(ARF), p16(INK4a), p53 and pRb, immunohistochemical stain was applied and their level of expression examined. RESULTS: The level of p53 expression was high when the stage of gastric cancer was more progressed, the invasiveness higher, lymph node metastasis present and cell differentiation poorer. In contrast, the level of p14ARF expression tended to be lower as the stage was more progressed, but this was not statistically significant. Expression of p16 and pRb did not show any association with stage or other pathologic findings. Expression of p53 and p14(ARF) also had a significant association with survival rate. Survival rate was lower in patients who expressed p53 than in those who did not, but it was higher in who expressed p14ARF than in those who did not. When these two were combined, patients with p14(ARF)(+)/p53(-) had the highest survival rate, whereas those with p14(ARF)(-)/p53(+)had the lowest. This demonstrated that the expressions of p14ART and p53 have value as prognostic indicators. CONCLUSION: From these results, p53 seems closely related to stage and other pathologic findings. Furthermore, p14(ARF) and p53 showed a statistically significant relationship with survival rate, making them valuable as prognostic indicators after surgery. In combination, it would be possible to predict a more accurate prognosis.

Expression and clinical significance of E2F-3 and pRb in human prostate cancer / 第三军医大学学报

Objective To study the expression of E2F-3 and pRb in primary prostate cancer(PCa) and its clinical significance.Methods The expression of E2F-3 protein and pRb was detected in 49 PCa,20 benign prostatic hyperplasia(BPH),10 normal prostate tissues(NP) by EliVision~(TM) plus immunohistochemical staining.Results The positive expression rate of E2F-3 in PCa,BPH,NP was 63.27%(31/49),20%((4/20)) and 10%(1/10),respectively.The expression level of E2F-3 in PCa was significantly higher than that in BPH(P

Relationship between E2F1 Expression and Clinical Outcome in Node-Positive Breast Cancer / 한국유방암학회지

PURPOSE: This study was performed to investigate whether the E2F1 protein expression can be used as a prognostic factor in clinical breast cancer. METHODS: The expressions of E2F1 and retinoblastoma protein (pRB) were analyzed in 165 lymph node positive breast cancers. All patients underwent adjuvant chemotherapy with fluorouracil, doxorubicin, and cyclophosphamide (FAC) after curative surgery. RESULTS: E2F1 was expressed in 43.6% and pRB was expressed in 46.1%. E2F1 expression was significantly increased in pRB-expressing tumors and was associated with S-phase fraction. By univariate survival analyses, E2F1 expression and ER were the significant prognostic factors for the disease recurrence and patient survival. E2F1 was the only significant prognostic factor for the patient outcome after FAC chemotherapy by multivariate analysis. CONCLUSION: Conclusion The results of the current study indicate that abnormal expression of E2F1 and pRB is prevalent and are intimately associated with each other in clinical breast cancer. A significant association between E2F1 expression and patient survival after FAC chemotherapy mondates a further validation study.

Human Papillomavirus Infection

The pathogenesis of cervical cancer is a clinically important example of multistage epithelial tumorigenesis from the progressive neoplastic changes known as premalignant cervical intraepithelial neoplasias (CINs) to invasive cervical cancers. Infection with high-risk human papillomavirus (HPV) types, such as HPV-16 and -18, is strongly correlated with the development of cervical cancer. The malignant phenotype of high-risk types depends on the expression of two viral oncogenes, E6 and E7. A number of genetic and biochemical studies have shown that E6 and E7 proteins cooperatively exert cellular immortalization and transformation by interfering with the functions of the cellular tumor suppressor proteins, p53 and pRb, respectively. The two oncoproteins inactivate the tumor suppressor proteins in such a way that E6 binds to p53 and promotes its ubiquitin/proteosome-dependent degradation and E7 binds to the hypophosphorylated form of pRb and interferes with its binding to E2F. In addition to these features of E6 and E7, other or additional activities have been reported that the independent of p53 and pRb in the course of cellular transformation. p73 was inactivated by both high-risk and low-risk HPV E6 proteins, independent of the E6-directed degradation. The inactivation of p73 by the high-risk E6 would provide another advantage for cervical carcinogenesis. We also found that HPV E7 is functionally associated with the interferon regulatory factor (IRF)-1 tumor suppressor, a key regulator of cellular immune response. Binding assays indicate a physical interaction between IRF-1 and HPV E7 at the molecular level both in vitro and in vivo. E7 transgene expression in an inducible cell line and transgenic mice abrogates transactivation function of IRF-1 in vivo, which might be important for the elucidation of the E7-mediated immune evading mechanism that is frequently found in cervical cancer. Furthermore, the functional inactivation of p73 or IRF-1 by both high-risk and low-risk HPV E6/E7 could play an important role in the malignant transformation and benign condyloma formation of the cervix.