Prognostic value of cyclin D1 overexpression in correlation with pRb and p53 status in non-small cell lung cancer (NSCLC)

Acer mono Extract Inhibits Invasive Activities and G1/S Transition of HT1080 Fibrosarcoma Cells

Acer mono is known to contain bioactive substances that exhibit beneficial effects in osteoporosis, gastric ulcers, hepatic damage, and pathologic angiogenesis. The current study aimed to investigate the effects of Acer mono extract on the invasive activities and cell-cycle progression of human fibrosarcoma cells. Cytotoxicity of Acer mono extract was assessed by MTT assay, in-vitro invasiveness of HT1080 fibrosarcoma cells was measured using matrigel assay, expression of invasion- and cell-cycle-related proteins was analyzed by western blot analysis, and that of E2F target genes was quantified using qRT-PCR. Acer mono extract did not show distinct cytotoxicity in the experimental concentrations used. Invasiveness of HT1080 fibrosarcoma cells and expression of cyclin D1 and CDK4 in them were significantly reduced in a dose-dependent manner after treatment with Acer mono extract. Acer mono extract showed inhibitory effects on the G1/S transition during cell-cycle progression; the active phosphorylated Rb protein level was decreased, and expression of E2F target genes was downregulated by the Acer mono extract. Our data collectively demonstrated that Acer mono extract exerts inhibitory effects on the invasiveness and cell-cycle progression of HT1080 human fibrosarcoma cells.

The prognostic value of cyclin D1 expression in the survival of cancer patients: A meta-analysis

BACKGROUND

The relationship between the expression of cyclin D1 and cancer prognosis and outcomes in different malignancies has not been fully elucidated.

AIMS

In the presented meta-analysis, we assessed the association between the expression level of cyclin D1 with overall survival (OS) in several cancers.

METHODS

Eligible studies were identified using PubMed, EMBase, Scopus, Web of Sciences and Cochrane Library databases. For the prognostic meta-analysis, study-specific hazard ratios (HRs) of tissue cyclin D1 for survival were obtained. Finally we pooled data derived from one hundred and eight studies comprising 19,224 patients with 10 different cancer types.

RESULTS

In the pooled analysis, high expression of cyclin D1 was significantly related to a poor OS with a pooled HR of 1.11 (95% CI: 1.02-1.20, P = 0.015; random-effects). Sub-group analysis revealed that high expression of cyclin D1 was related to worse OS of head and neck cancers (HR = 2.08, 95% CI: 1.75-2.47; P < 0.001), but not in breast (HR = 1.033, 95% CI: 0.873-1.223, P = 0.702), gastrointestinal (HR = 1.025, 95% CI:0.824-1.275; P = 0.825), bladder (HR = 0.937, CI: 0.844-1.041; P = 0.225) and in lung cancer patients (HR = 1.092, CI: 0.819-1.455; P = 0.549).

CONCLUSION

Further large, prospective, and well-designed trials are warranted to elucidate the precise clinical importance of cyclin D1 overexpression in the prognosis of cancer patients receiving different treatment regimens.

Effects of zerumbone on proliferation and apoptosis of esophageal cancer cells and on P53 and Bcl-2 expression levels

The effects of zerumbone on the proliferation and apoptosis of esophagus cancer cells and on the P53 and Bcl-2 expression levels were studied. The esophagus cancer EC-109 cells were cultured and inoculated. The effect of zerumbone on proliferation of EC-109 cells was detected via the Cell Counting Kit-8 (CCK-8) method. Cell apoptosis was detected via TdT-mediated dUTP nick end-labeling (TUNEL) staining. Moreover, the mRNA expression levels of P53 and Bcl-2 were detected via reverse transcription-polymerase chain reaction (RT-PCR), and the protein expression levels of P53 and Bcl-2 were evaluated via western blotting. CCK-8 detection results showed that compared with control group, zerumbone in different concentrations could inhibit the activity of EC-109, and the proliferation inhibition rate was significantly increased in a concentration-dependent manner with the increase of concentration. TUNEL staining showed that cell apoptosis gradually occurred in administration group, and the number of apoptotic cells was increased in a concentration-dependent manner with the increase of concentration. RT-PCR detection results showed that the mRNA expression level of P53 in administration group was significantly increased compared with that in control group, but that of Bcl-2 was significantly decreased. Western blotting showed that the protein expression level of Bcl-2 in administration group in different concentrations was significantly increased with the increase of zerumbone concentration, but that of Bcl-2 was significantly decreased in a concentration-dependent manner. Zerumbone can inhibit the proliferation and induce apoptosis of esophageal cancer EC-109 cells, and its induction of apoptosis may be realized through upregulating the mRNA expression of P53 and downregulating the mRNA expression of Bcl-2, and upregulating the protein expression of P53 and downregulating the protein expression of Bcl-2.

Expression and prognostic relevance of STAT3 and cyclin D1 in non-small cell lung cancer

Aim

To guide clinicians in selecting treatment options for patients with non-small cell lung cancer (NSCLC), it is desirable to have reliable markers predicting clinical outcome. This study analyzed the correlation between signal transducer and activator of transcription 3 (STAT3) and cyclin D1 in NSCLC and their association with clinicopathological features and survival.

Methods

We investigated 65 specimens of NSCLC tissues by immunohistochemistry using STAT3 and cyclin D1 antibodies. First we determined the correlation between STAT3 and cyclin D1 expression and the clinicopathological features of the tumor. Then we assessed the prognostic relevance of STAT3 and cyclin D1.

Results

A significant correlation was found between high levels of STAT3 expression and the degree of tumor differentiation. Additionally, a significant positive correlation was found between the expression of STAT3 and cyclin D1 (r=0.405, p=0.001). The overexpression of STAT3 and the presence of metastasis were significantly associated with shorter overall survival in univariate analysis (p=0.028 and p=0.036, respectively). Multivariate analysis confirmed that STAT3 expression was an independent prognostic factor (p=0.001).

Conclusions

STAT3 might be correlated with tumor differentiation, and its elevated expression may be an adverse prognostic indicator for patients with NSCLC. Activation of the STAT3/cyclin D1 signaling pathway may be attributed to the malignant transformation of NSCLC and may represent a possible target for therapy.

Exosomal miRNAs as biomarkers of recurrent lung cancer

Prognosis of lung cancer still remains grim largely due to recurrence and aggressive metastasis of the disease. In this study, we examined the potential of exosomal miRNAs as biomarkers of recurrent lung cancer. Initially, in vitro miRNA profiles of normal lung (Beas-2b) and lung cancer (H1299) cells and of exosomes isolated from conditioned media were determined. In vivo study involved establishing subcutaneous primary and recurrent lung cancer xenografts in nude mouse model and examining tumor and serum exosomal miRNA alteration in secondary/recurrent lung tumors. A total of 77 miRNAs were observed to be significantly modulated in the H1299 cells (47 miRNA upregulated and 30 downregulated) compared to the Beas-2b cells. The exosomes isolated from conditioned media indicated several miRNAs which were in agreement with cells of origin. A similarity was also observed between miRNAs from serum exosomes and tumors, indicating their origin from the lung tumors. Two miRNAs, miR-21 and miR-155, were found to be significantly upregulated in recurrent tumors compared to primary tumors. These miRNAs were also upregulated in serum exosomes of recurrent tumor-bearing animals versus non-tumor- or primary tumor-bearing animals. Increased expression of the recurrent disease markers were also observed in recurrent tumors compared with primary tumors. Serum exosomes from recurrent tumor mice mirrored its tumor profile in expressing higher levels of these proteins compared with exosomes from primary tumor mice. Our data suggest that exosomal miRNA signatures may be a true representation of a pathological profile of lung cancer; thus, miRNAs could serve as promising biomarkers for non-invasive diagnosis of the disease.

Prognostic markers in lung cancer: is it ready for prime time?

Non-small cell lung cancer (NSCLC) is a heterogeneity disease and to date, specific clinical factors and tumor stage are established as prognostic markers. Nevertheless, prognosis within stage may vary significantly. During the last 3 decades, genes/proteins that drive tumor initiation and progression, such as oncogenes and tumor suppressor genes have been studied as additional potential prognostic markers. The protein markers as evaluated by immunohistochemistry (IHC) have previously dominated these studies. However, with the development of high-throughput techniques to interrogate genome wide genetic or gene expression changes, DNA (copy number and mutation) and RNA (mRNA and microRNA) based markers have more recently been studied as prognostic markers. Largely due to the heterogeneity and complexity of NSCLC, single gene markers including KRAS mutation has not been validated as strong prognostic markers. In contrast, several gene expression signatures representing mRNA levels of multiple genes have been developed and validated in multiple microarray datasets of independent patient cohorts. The salient features of these gene signatures and their potential value to predict benefit from adjuvant chemotherapy is discussed.

Regulatory effects of deguelin on proliferation and cell cycle of Raji cells

The underlying mechanism of deguelin regulating the cell cycle in human Burkitt's lymphoma cell line Raji cells in vitro, and the cytotoxicity of deguelin to Raji cells and human peripheral blood monocular cells (PBMCs) were investigated. The effects of deguelin on the growth of Raji cells were studied by 3-(4, 5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium (MTT) assay. Apoptosis was detected through Hoechst 33258 staining. The effect of deguelin on the cell cycle of Raji cells was studied by a propidium iodide method. The expression levels of cyclin D1, P21 and pRb were examined by using Western blotting. The results showed that the proliferation of Raji cells was inhibited in the deguelin-treated group, with a 24-h IC(50) value of 21.61 nmol/L and a 36-h IC(50) value of 17.07 nmol/L. Proliferation in Raji cells was inhibited significantly by deguelin, while little change was observed in PBMCs. Deguelin induced G(2)/M arrest in Raji cells. The expression of cyclin D1, P21 and pRb was dramatically down-regulated by deguelin in a dose-dependent manner. It was concluded that deguelin could inhibit the proliferation of Raji cells by arresting the cells at G(2)/M phase and inducing the cell apoptosis. Moreover, deguelin selectively induced apoptosis of Raji cells with low toxicity to PBMCs. The antitumor effects of deguelin were related to the down-regulated expression of cyclin D1, P21 and pRb proteins.

Peripheral T-cell Lymphoma with Cyclin D1 overexpression: a case report

Peripheral T-cell lymphomas not otherwise specified are generally considered aggressive non-Hodgkin lymphomas, because of poor natural outcome and response to therapy. They show a complex karyotype without any specific genetic hallmark. We report a case of peripheral T-cell lymphoma not otherwise specified with heterogeneous nuclear Cyclin D1 immunohistochemical overexpression, due to gene copy gain, a phenomenon similar to that observed in Mantle Cell Lymphoma characterized by t(11;14)(q13;q32). In this case report we underline the diagnostic pitfall rapresented by Cyclin D1 immunoistochemical overexpression in a T-cell lymphoma. Several pitfalls could lead to misinterpretation of diagnosis, therefore, we underlined the need to integrate the classical histology and immunohistochemistry with molecular tests as clonality or Fluorescence in situ hybridization.

The role of cyclin D1 expression and patient's survival in non-small-cell lung cancer: a systematic review with meta-analysis

BACKGROUND

The role of cell-cycle protein cyclin D1 in lung cancer remains controversial. To clarify its impact on survival in non-small-cell lung cancer (NSCLC), we performed a meta-analysis on the currently available medial literature to quantitatively assess its role on survival of NSCLC according to cyclin D1 status.

METHOD

Published studies that investigated the association between cyclin D1 expression and NSCLC survival were identified. Meta-analysis was performed by using a DerSimonian-Laird model. Funnel plot was used to investigate publication bias and sources of heterogeneity were identified by using meta-regression analysis.

RESULT

A total of 24 studies with 2731 patients were evaluable for this meta-analysis. No statistical significance was found that cyclin D1 expression was associated with poor prognosis in NSCLC (hazard ratio 1.08 [95% CI, 0.80-1.45]) without publication bias found. But there was significant heterogeneity present; meta-regression analysis was used to explore the sources of heterogeneity and revealed that the outcome of analysis was influenced by cutoff values and ethnicity. No difference between positive and negative studies on study quality assessment was present.

CONCLUSION

The cyclin D1 expression is unlikely to be useful as a prognostic marker for NSCLC in clinical practice from current evidence. The conclusion should be confirmed by a large well-designed prospective study.

Cyclin D1 splice variants: polymorphism, risk, and isoform-specific regulation in prostate cancer

PURPOSE

Alternative CCND1 splicing results in cyclin D1b, which has specialized, protumorigenic functions in prostate not shared by the cyclin D1a (full length) isoform. Here, the frequency, tumor relevance, and mechanisms controlling cyclin D1b were challenged.

EXPERIMENTAL DESIGN

First, relative expression of both cyclin D1 isoforms was determined in prostate adenocarcinomas. Second, relevance of the androgen axis was determined. Third, minigenes were created to interrogate the role of the G/A870 polymorphism (within the splice site), and findings were validated in primary tissue. Fourth, the effect of G/A870 on cancer risk was assessed in two large case-control studies.

RESULTS

Cyclin D1b is induced in tumors, and a significant subset expressed this isoform in the absence of detectable cyclin D1a. Accordingly, the isoforms showed noncorrelated expression patterns, and hormone status did not alter splicing. Whereas G/A870 was not independently predictive of cancer risk, A870 predisposed for transcript-b production in cells and in normal prostate. The influence of A870 on overall transcript-b levels was relieved in tumors, indicating that aberrations in tumorigenesis likely alter the influence of the polymorphism.

CONCLUSIONS

These studies reveal that cyclin D1b is specifically elevated in prostate tumorigenesis. Cyclin D1b expression patterns are distinct from that observed with cyclin D1a. The A870 allele predisposes for transcript-b production in a context-specific manner. Although A870 does not independently predict cancer risk, tumor cells can bypass the influence of the polymorphism. These findings have major implications for the analyses of D-cyclin function in the prostate and provide the foundation for future studies directed at identifying potential modifiers of the G/A870 polymorphism.

Inhibition of tumor growth and metastasis by non-small cell lung cancer cells transfected with cyclin D1-targeted siRNA

To observe whether cyclin D1 siRNA-mediated inhibition of cyclin D1 represents a promising antigrowth and antimetastatic strategy for cancer gene therapy, particularly for non-small cell lung cancers. To stably transfect the A549 cell line with a cyclin D1-targeted siRNA to downregulate cyclin D1 expression and observe the effects on protein expression, and tumor growth in vitro and in vivo. Expression of cyclin D1-targeted siRNA resulted in a decrease in cyclin D1, MMP-2, RhoA, and Rac1 protein levels, as detected by Western blot and immunofluorescence studies. Transfected cells also exhibited a marked decrease in the rate of cell growth, and decreased invasive capacity, compared to cells transduced with a scrambled siRNA plasmid and untransduced A549 cells. siRNA-mediated inhibition of cyclin D1 expression represents a promising antigrowth and antimetastatic strategy for cancer gene therapy, particularly for non-small cell lung cancers. It is the reason for inhibiting tumor growth so that cyclin D1 siRNA can inhibit the cell cycle progression. In addition, the mechanism of inhibiting tumor metastasis was related to the decrease in the expression of MMP-2, RhoA, and Rac1 after cyclin D1 was decreased by cyclin D1 siRNA.

Prognostic value of the apoptotic index analysed jointly with selected cell cycle regulators and proliferation markers in non-small cell lung cancer

In a previous small series of surgically treated non-small cell lung cancer patients (NSCLC), we found that higher apoptotic index (AI) negatively influenced survival (Dworakowska D, Jassem E, Jassem J, Karmolinski A, Dworakowski R, Wirth T, et al. Clinical significance of apoptotic index in non-small cell lung cancer: correlation with p53, mdm2, pRb and p21WAF1/CIP1 protein expression. J Cancer Res Clin Oncol 2005; 131:617-623.). In this study we attempted to verify our previous finding in larger group of 170 NSCLC cases, additionally correlating AI to selected cell cycle regulators as well as a proliferation marker. Apoptosis was assessed with the use of the TUNEL technique, whereas the expression of p53, pRb, mdm2, p21(WAF1/CIP1), cyclin D1 and PCNA were assessed immunohistochemically. The mean and the median AI was 12 and 8, respectively. The expression of p53, pRb, mdm2, p21(WAF1/CIP1) proteins and cyclin D1 was found in 47%, 71%, 37%, 65% and 40% of cases, respectively. The mean and the median PCNA labeling index (PCNA LI) was 34 and 35, respectively. AI was not correlated with any patient characteristic or other tumor markers. In uni- and multivariate analysis AI, analysed separately or jointly with cell cycle regulators and PCNA LI, did not influence disease-free or over-all survival. However, patients with "very high AI/very high PCNA LI" had a particularly poor prognosis (P=0.001). Patients with "very low AI/negative pRb" phenotype survived for a shorter time in comparison to others (P=0.04). In addition, patients with the highest PCNA LI had a worse outcome in comparison to patients with the lowest PCNA LI (P=0.04), especially those with concomitant p53 protein expression (P=0.026) or lacking pRb protein expression (P=0.04). This study demonstrates that joint analysis of several factors involved in apoptosis, proliferation and cell cycle regulation, but not AI alone, might provide additional prognostic information in NSCLC patients.

Impact of differential cyclin D1 expression and localisation in prostate cancer

Cyclin D1 is a critical regulator of androgen-dependent transcription and cell cycle progression in prostate cancer cells. Despite the influence of D-type cyclins on prostate cancer proliferation, few studies have examined the expression of cyclin D1 in localised tumours or challenged its relevance to disease progression. Cyclin D1 status was characterised using immunohistochemistry in 38 non-neoplastic prostate samples, 138 primary human prostate carcinomas, and three lymph node metastatic specimens. Relevance of cyclin D1 to preoperative prostate-specific antigen (PSA) levels, Ki-67 index, and p21^Cip1 status was also examined. Cyclin D1-positive phenotype was increased in primary carcinoma compared to non-neoplastic tissue, and was evident in all lymph node metastases cases. Interestingly, at least three distinct localisation patterns were observed in the cyclin D1-positive cohort, wherein cytoplasmic localisation was identified in a large fraction, and this pattern was predominant in lower grade tumours. Relevance of altered cyclin D1 status was observed, wherein cyclin D1-positive tumours were associated with low preoperative PSA levels, consistent with in vitro reports that cyclin D1 may alter the expression of this tumour marker. Moreover, tumours with predominantly cytoplasmic cyclin D1 showed the lowest Ki-67 index, whereas nuclear cyclin D1 was associated with higher grade, elevated Ki-67, and increased nuclear p21^Cip1. These data demonstrate that differential cyclin D1 status may influence clinicopathological parameters, and reveal new insight as to the regulation and potential consequence of cyclin D1 expression in prostate cancer.

Cyclin D1 in non-small cell lung cancer: a key driver of malignant transformation

PURPOSE

To review the evidence implicating the deregulation of cyclin D1 in the pathogenesis of non-small cell lung cancer (NSCLC), and to discuss the opportunities for targeted clinical intervention.

METHODS

Data published until June 2006 are summarized, and previously unpublished results from our own research are included.

RESULTS

In normal cells, cyclin D1 complexes with and activates cyclin-dependent kinases (CDK) and acts as a transcriptional regulator. The protein is frequently overexpressed in a wide range of cancers, sometimes coincident with CCND1 (cyclin D1) gene amplification (5-20% of tumours). A low level of somatic mutations have been seen in certain tumours. CCND1 is amplified in NSCLC and cyclin D1 is frequently overexpressed in tumours and pre-invasive bronchial lesions, generally from one parental allele. Mutation analyses revealed a frequent CCND1 gene polymorphism (A870G) that modulates alternative splicing and allows expression of an alternative cyclin D1 transcript (transcript cyclin D1b). The encoded cyclin D1b protein lacks a specific phosphorylation site required for nuclear export. Genotype has been correlated with the risk and/or severity of disease or drug response across a range of malignancies, including lung cancer. Together, these findings suggest a strong pathological role for cyclin D1 deregulation in bronchial neoplasia.

CONCLUSION

Current data indicate that cyclin D1 overexpression is not a consequence of, but rather a pivotal element in the process of malignant transformation in the lung and other tissues. This understanding may open new avenues for lung cancer diagnosis, treatment and prevention.

Immunohistochemical markers of prognosis in non-small cell lung cancer: a review and proposal for a multiphase approach to marker evaluation

Characteristics of the tumour that affect and predict the survival outcome of patients with cancer are prognostic markers for cancer. In non-small cell lung carcinoma (NSCLC), stage is the main determinant of prognosis and the basis for deciding options for treatment. Patients with early-stage tumour are treated by complete surgical resection, which is curative in 40-70% of patients. That there are other factors important in determining the biology of these tumours, especially genes that have a role in metastasis, is indicated. Such factors could potentially be used to further classify patients into groups according to substages that may be treated differently. During the past decade, a large number of proteins that are putatively important in carcinogenesis and cancer biology have been studied for their prognostic value in NSCLC, but none of them have been proved to be sufficiently useful in clinical diagnosis. Several markers (epidermal growth factor receptor, human epidermal growth factor receptor 2, Ki-67, p53 and Bcl-2) have been studied exhaustively. Ki-67, p53 and Bcl-2 are suggested to be important but weak prognostic markers, by meta-analyses of the results. Cyclin E, vascular endothelial growth factor A, p16(INK4A), p27(kip1) and beta-catenin are promising candidates, but require further study in large randomised clinical trial samples by using standardised assays and scoring systems. Some issues and inconsistencies in the reported studies to date are highlighted and discussed. A guideline for a multi-phase approach for conducting future studies on prognostic immunohistochemistry markers is proposed here.

Regulation of the G1/S phase of the cell cycle and alterations in the RB pathway in human lung cancer

The retinoblastoma (RB)-Cyclin (CCN)D1-p16 cell cycle pathway has a crucial role in lung tumorigenesis. Impairment of the RB pathway has been shown to occur in almost all lung tumors. A deregulation at any level of this core RB pathway seems to make cells insensitive to the mitogenic signaling that is required for cell cycle progression. To date, almost all participants in this pathway have been shown to be altered to a various degree in lung tumors. Some of the alterations are mutually exclusive, including RB and p16INK4A . In small cell lung cancer, the RB tumor suppressor gene is inactivated in almost 90% of the tumors, whereas in non-small cell lung cancer, the cyclin-dependent kinase (CDK)4 inhibitor p16INK4A is inactivated in 40-60% of the tumors. Many mechanisms may be responsible for activating the RB-Cyclin D1 pathway, including activating (CDK4) and inactivating mutations (p16INK4A ), deletions (RB and p16INK4A ), amplifications (CCND1 and CDK4), silencing methylation (p16INK4A and RB), and hyper-phosphorylation (RB). As some of these alterations, such as p16INK4A methylation, can also be detected in bronchial lavage and serum, they could potentially serve as useful markers for the early detection of lung cancer. This review summarizes recent experiments describing the variable roles of key-player molecules of the RB pathway and different mechanisms by which the RB pathway can be altered in lung cancer.