Cyclin D1 expression and early breast cancer recurrence following lumpectomy and radiation

MicroRNA-374b inhibits breast cancer progression through regulating CCND1 and TGFA genes

Emerging evidence indicates that microRNAs (miRNAs) play a critical role in breast cancer development. We recently reported that a higher expression of miR-374b in tumor tissues was associated with a better disease-free survival of triple-negative breast cancer (TNBC). However, the functional significance and molecular mechanisms underlying the role of miR-374b in breast cancer are largely unknown. In this current study, we evaluated the biological functions and potential mechanisms of miR-374b in both TNBC and non-TNBC. We found that miR-374b was significantly downregulated in breast cancer tissues, compared to adjacent tissues. MiR-374b levels were also lower in breast cancer cell lines, as compared to breast epithelial cells. In vitro and in vivo studies demonstrated that miR-374b modulates the malignant behavior of breast cancer cells, such as cell proliferation in 2D and 3D, cell invasion ability, colony-forming ability and tumor growth in mice. By using bioinformatics tools, we predicted that miR-374b plays a role in breast cancer cells through negatively regulating cyclin D1 (CCND1) and transforming growth factor alpha (TGFA). We further confirmed that CCND1 and TGFA contribute to the malignant behavior of breast cancer cells in vitro and in vivo. Our rescue experiments showed that overexpressing CCND1 or TGFA reverses the phenotypes caused by miR-374b overexpression. Taken together, our studies suggest that miR-374b modulates malignant behavior of breast cancer cells by negatively regulating CCND1 and TGFA genes. The newly identified miR-374b-mediated CCND1 and TGFA gene silencing may facilitate a better understanding of the molecular mechanisms of breast cancer progression.

Karenitecin (bnp1350) and flavopridol as radiosensitizers in malignant glioma

The poor prognosis of malignant glioma patients highlights the need to develop low toxicity, tumor specific agents with the ability to synergize with proven efficacious treatment modalities, e.g., ionizing irradiation. This paper investigates the potential of BNP1350 (karenitecin), a topoisomerase I-targeting anticancer agent, and flavopridol a cyclin-dependent kinase inhibitor as radiosensitizers at clinically relevant doses in glioblastoma cell lines. A clonogenic survival and apoptosis assays were performed to test the effect of karenitecin (0.1 nM to 10 nM), flavopridol, (50 nM to 500 nM), radiation (1 Gy to 5.5 Gy) and a combination of radiation and karenitecin or radiation and flavopridol on the glioma cell lines T986 and M059K. Cells were stained for cyclins B and D using antibodies followed by flow cytometry. Propidium Iodide staining was used to reveal the various phases of the cell cycle; cyclin staining in the G0/G1 and G2/M phase of the cell cycle was estimated as the Mean Fluorescence Intensity (MFI) after subtracting the MFI recorded by the isotype controls. Results demonstrated that in irradiated cells, pretreatment with karenitecin induced apoptosis, a transient arrest in the G2/M phase of the cell cycle and increased the expression of cyclin B1. Flavopridol treatment also induced apoptosis and a transient block in the G2/M phase of the cell cycle. The combined effects of karenitecin and flavopridol displayed synergistic effects. The unique radiosensitizing activity of orally administrable karenitecin and flavopridol is consistent with continued investigation of these compounds preclinically, as well as in the clinical setting.

Expression profiling of 21 biomolecules in locally advanced nasopharyngeal carcinomas of Caucasian patients

Background

Since scarce data exist on the pathogenesis of nasopharyngeal carcinoma in Caucasian patients, we attempted to elucidate the responsible molecular pathways in this patient population.

Methods

Formalin-fixed paraffin-embedded tumor tissue samples from 107 patients, diagnosed with locally-advanced nasopharyngeal carcinoma and treated with chemotherapy or chemo-radiotherapy, were analyzed by immunohistochemistry for the expression of the following proteins: E-cadherin, P-cadherin, Fascin-1, Cyclin D1, COX-2, EGFR, VEGF-A, VEGF-C, VEGFR-2, VEGFR-3, ERCC1, p53, p63, Ki67, MAPT, phospho-p44/42MAPK, PTEN, phospho-AKT, phospho-mTOR, and phospho-GSK-3β. EBER status was assessed by in situ hybridization. The majority of the cases were included in tissue microarray. All stains were performed and assessed centrally by two pathologists. The median follow-up time was 76.8 (42.3 – 99.2) months.

Results

Biomolecules expressed in >90% of cases were: p53, COX-2, P-cadherin, EBER, phospho-GSK-3β, and Fascin-1. WHO II+III tumors were more frequently EBER & PTEN positive and VEGF-A negative. Advanced age was significantly associated with positive phospho-GSK-3β and ERCC1 expression; male gender with positive phospho-AKT and phospho-p44/42MAPK; and worse performance status (1 or 2) with negative Ki67, ERCC1, PTEN, and phospho-mTOR expression. Earlier disease stage was closely associated with p63, MAPT, PTEN, and Cyclin D1 positivity. Univariate Cox regression analysis highlighted Cyclin D1 as a negative prognostic factor for disease-free survival (p=0.034) and EBER as a positive one for overall survival (p=0.048). In multivariate analysis, advanced age and stage, poor performance status, and positive ERCC1 emerged as predictors of worse disease-free and overall survival, as opposed to positive phospho-mTOR. Clustering analysis defined two protein-expression groups being predictive of better overall survival (p=0.043).

Conclusions

Our study is the first to examine the activation and interaction of established biomolecules and signaling pathways in Caucasian NPC patients in an effort to reveal new therapeutic targets.

Nuclear EGFR in ductal invasive breast cancer: correlation with cyclin-D1 and prognosis

The epidermal growth factor receptor (EGFR)-family and cyclin-D1 have been extensively studied in breast cancer; however systematic studies that examine protein expression and gene status in the same cohort of patients are lacking. Also emerging evidences suggest existence of a direct EGFR-signaling pathway, which involves cellular transport of EGFR from cell membrane to the nucleus, and transcriptional regulation of the target genes. Thus, we examined the protein expression of membrane EGFR, nuclear EGFR, cyclin-D1 and the corresponding gene status in 113 breast carcinomas by immunohistochemistry and fluorescence in situ hybridization using tissue microarrays. Membrane EGFR overexpression and EGFR gene amplification were detected in 2% cases, while nuclear EGFR was detected in 40% of cases, with 12% having high nuclear EGFR staining. Nuclear EGFR correlated with tumor size (P=0.0005), lymph node metastasis (P=0.0288), Nottingham prognostic index (P=0.0011) and estrogen receptor (ER) expression (P=0.0258) but the letter correlation was observed only in premenopausal group of patients. Strong cyclin-D1 expression and cyclin-D1 gene (CCND1) amplification were found in 64 and 13% of the cases, respectively. Cyclin-D1 expression showed positive correlation with ER (P=0.0113) and inverse correlation with Nottingham prognostic index (P=0.0309) and membrane EGFR (P=0.0201). CCND1 amplification also showed inverse correlation with membrane EGFR (P=0.0420). A strong correlation between membrane EGFR expression and gene amplification (P=0.0035), as well as cyclin-D1 overexpression and gene amplification (P=0.0362), was demonstrated. On univariate analysis cyclin-D1 expression showed a correlation with longer overall survival in the premenopausal group and nuclear EGFR correlated with shorter overall survival in whole cohort as well in the premenopausal group of patients. Multivariate analysis revealed nuclear EGFR to be an independent prognostic factor and showed 3.4 times greater mortality risk for nuclear EGFR+++ patients as compared with nuclear EGFR negative patients (hazard ratio =3.402; P=0.0026).

Expression of cell cycle proteins in male breast carcinoma

Introduction

Male breast cancer (MBC) is a rare, yet potentially aggressive disease. Although literature regarding female breast cancer (FBC) is extensive, little is known about the etiopathogenesis of male breast cancer. Studies from our laboratory show that MBCs have a distinct immunophenotypic profile, suggesting that the etiopathogenesis of MBC is different from FBCs. The aim of this study was to evaluate and correlate the immunohistochemical expression of cell cycle proteins in male breast carcinoma to significant clinico-biological endpoints.

Methods

75 cases of MBC were identified using the records of the Saskatchewan Cancer Agency over 26 years (1970-1996). Cases were reviewed and analyzed for the immunohistochemical expression of PCNA, Ki67, p27, p16, p57, p21, cyclin-D1 and c-myc and correlated to clinico-biological endpoints of tumor size, node status, stage of the disease, and disease free survival (DFS).

Results

Decreased DFS was observed in the majority of tumors that overexpressed PCNA (98%, p = 0.004). The overexpression of PCNA was inversely correlated to the expression of Ki67 which was predominantly negative (78.3%). Cyclin D1 was overexpressed in 83.7% of cases. Cyclin D1 positive tumors were smaller than 2 cm (55.6%, p = 0.005), had a low incidence of lymph node metastasis (38.2%, p = 0.04) and were associated with increased DFS of >150 months (p = 0.04). Overexpression of c-myc (90%) was linked with a higher incidence of node negativity (58.3%, p = 0.006) and increased DFS (p = 0.04). p27 over expression was associated with decreased lymph node metastasis (p = 0.04). P21 and p57 positive tumors were related to decreased DFS (p = 0.04). Though p16 was overexpressed in 76.6%, this did not reach statistical significance with DFS (p = 0.06) or nodal status (p = 0.07).

Conclusion

Aberrant cell cycle protein expression supports our view that these are important pathways involved in the etiopathogenesis of MBC. Tumors with overexpression of Cyclin D1 and c-myc had better outcomes, in contrast to tumors with overexpression of p21, p57, and PCNA with significantly worse outcomes. P27 appears to be a predictive marker for lymph nodal status. Such observation strongly suggests that dysregulation of cell cycle proteins may play a unique role in the initiation and progression of disease in male breast cancer. Such findings open up new avenues for the treatment of MBC as a suitable candidate for novel CDK-based anticancer therapies in the future.

Identification of aberrant cell cycle regulation in Epstein-Barr virus-associated nasopharyngeal carcinoma by cDNA microarray and gene set enrichment analysis

Previous studies have revealed that Epstein-Barr virus (EBV) was closely associated with nasopharyngeal carcinoma (NPC). This study aimed to characterize the global pathways affected in the EBV-associated NPC. Combined with microdissection, gene expression profiles in 22 NPCs and 10 non-tumor nasopharyngeal epithelial (NPE) tissue samples were analyzed. All NPC specimens served in the microarray analysis were positive for EBV, as judged by identification of the expression of EBV nuclear antigen 1 (EBNA1). Through gene set enrichment analysis (GSEA), we found that cell cycle pathway was the most disregulated pathway in NPC (P=0.000, false discovery rate q-value=0.007), which included some aberrant expressed components. We first found that overexpression of CDK4, cyclin D1, and Rb proteins, and loss of expression of proteins p16, p27, and p19 were statistically significant in NPC tissues compared with non-cancerous NPE (P<0.05) by real-time RT-PCR and tissue microarray. EBV-encoded small RNA-1 (EBER-1) hybridization signals in the NPC showed significant associations with the overexpression of Rb (P=0.000), cyclin D1 (P=0.000), CDK4 (P=0.000), and the loss of expression of p16 proteins (P=0.039). In the final logistic regression analysis model, EBER-1 and abnormal expression of p16, Rb, cyclin D1, and E2F6 were independent contributions to nasopharyngeal carcinogenesis. Through survival analysis, only cyclin D1 could predict the prognosis of NPC patients. These results suggested that cell cycle pathway was the most disregulated pathway in the EBV-associated NPC, and EBER-1 was closely associated with p16, CDK4, cyclin D1, and Rb.cyclin D1 could be the prognosis biomarker for NPC.

Bcl-2 expression predicts local relapse for early-stage breast cancer receiving conserving surgery and radiotherapy

BACKGROUND

This study was undertaken to evaluate the prognostic significance of Bcl-2, a apoptosis-related protein, in patients with early stage breast cancer treated with breast conservation treatment (BCT).

METHODS

After obtaining IRB approval, 504 patients with early stage breast cancer treated with BCT were entered in this study. The paraffin specimens were constructed into tissue micro-arrays with two-fold redundancy, processed and stained for Bcl-2 antibody. Bcl-2 expression was correlated with other clinicopathological parameters and clinical outcomes.

RESULTS

Bcl-2 expression was identified in 116 cases (28%). Bcl-2 expression was positively correlated with both estrogen receptor and progesterone receptor status (P < 0.0001, respectively). Bcl-2 expression was associated with ipsilateral breast tumor recurrence (P = 0.0322, by log-rank test). Multivariate analysis using Cox proportional hazard model showed that Bcl-2 expression still retained significance as an independent prognostic factor for breast recurrence (P = 0.0348).

CONCLUSIONS

Bcl-2 expression is highly associated with an increased risk of local recurrence in patients with early stage breast cancer. Immunohistochemical staining of the primary tumor for Bcl-2 might be useful to select optimal treatment options for these patients.

Oncogenic virus-associated neoplasia: a role for cyclin D1 genotypes influencing the age of onset of disease?

Cyclin D1 (CCND1) is a key regulatory protein at the G1/S checkpoint of the cell cycle. The purpose of our study was to assess the role of CCND1 genotypes influencing the age of onset of oncogenic virus-associated neoplasia. We conducted a hospital-based case-control study of 581 individuals, including 247 controls and 334 cases (108 nasopharyngeal and 226 cervical cancer cases). The polymorphism analysis was performed in blood samples by PCR-RFLP methodology. Age-adjusted logistic regression analysis indicates that individuals carrying two G-alleles have an increased genetic susceptibility for the development of oncogenic virus-associated cancers (aOR=2.02, 95% CI 1.30-3.14, P=0.002). Moreover, our results indicate that the waiting time for onset of oncogenic virus-associated neoplasia in patients homozygous (GG) for CCND1 genotypes (52 years) was 12 years earlier in comparison with patients carrying AG or AA genotypes (60 years) (log-rank test: P=0.0003). Our results may be important in contributing to a more extensive knowledge of the mechanisms involved in oncogenic virus-associated carcinogenesis, as CCND1 may be an important target for the development of new strategies for cancer treatment and prevention.

Outcomes in Young Women With Breast Cancer of Triple-Negative Phenotype: The Prognostic Significance of CK19 Expression

PURPOSE

Basal-like carcinoma of the breast is associated with genetic instability and aggressive behavior. In this study, we evaluated the luminal cytokeratin marker CK-19 in young women with breast cancer treated with conservative surgery and radiation therapy (CS+RT).

METHODS

Primary tumor specimens from a cohort of 158 young premenopausal women (range, 25-49 years) treated with CS+RT with a median follow-up of 6.25 years were constructed into a tissue microarray. The array was stained for ER, PR, HER2, CK19, and p53. The molecular profiles were correlated with clinical-pathologic factors, overall, local, and distant relapse-free survival. The association between CK19, other co-variables, and outcome was assessed in a multivariate model.

RESULTS

Positive expression of ER, PR, HER-2/neu, CK19, and p53 were 33.1%, 34.5%, 10.0%, 79.5%, and 20.9%, respectively. With 20 local relapses and 38 distant metastases, the 10-year overall, breast relapse-free, and distant relapse-free survival were 79.65%, 87.29%, and 67.35%, respectively. Tumor stage and nodal status were associated with distant relapse-free and overall survival. In multivariate analysis, CK19 negativity was a predictor poor local (RR, 3.54; 95% CI, 1.87-7.65; p < 0.01) distant (RR, 1.44; 95% CI, 0.86-2.70; p = 0.17), and overall survival (RR, 1.89; 95% CI, 1.04-3.55; p = 0.03).

CONCLUSIONS

Lack of CK19 expression identifies a subset of patients with a significantly higher risk of local relapse. Distant relapse and overall survival rates also correlated with CK19 negativity. Further evaluation of the prognostic significance of basal and luminal cytokeratins in young women with breast cancer is warranted.

p53 overexpression is a predictor of local recurrence after treatment for both in situ and invasive ductal carcinoma of the breast

BACKGROUND

Several biological markers have been related to prognosis in mammary ductal carcinoma. The aim of the study was to determine biological markers that could predict local recurrence following treatment for all stages of primary operable ductal carcinoma of the breast.

MATERIALS AND METHODS

A consecutive series of patients treated for pure ductal carcinoma in situ (DCIS, n = 110) and invasive ductal carcinoma (IDC, n = 243) was studied. Twenty-three patients with DCIS were excluded because of lack of original paraffin embedded tissue. All patients had been treated between July 1996 and December 2001. Median follow-up was 49.8 mo. From the original paraffin embedded tumors, tissue microarrays (TMAs) were constructed. On these TMAs, immunohistochemistry was performed for estrogen-receptor (ER), progesterone-receptor (PR), Her2/neu, p53, and cyclin D1. Main outcome was the event of LR. All analyses were stratified for diagnosis (DCIS or IDC) and pathological grade.

RESULTS

In univariate analyses, Her2/neu overexpression (hazard ratio [HR] 3.1, 95% confidence interval [CI] 1.1-8.7, P = 0.032) and p53 overexpression (HR 3.5, 95% CI 1.3-9.3, P = 0.014) were associated with LR in patients treated for both DCIS and IDC. In multivariate analysis, p53 overexpression (HR 3.0, 95% CI 1.1-8.2, P = 0.036 and HR 4.4, 95% CI 1.5-12.9, P = 0.008) and adjuvant radiotherapy (HR 0.2, 95% CI 0.1-0.8, P = 0.026) were independent common predictors of LR in patients who had received treatment for both DCIS and IDC.

CONCLUSIONS

p53 overexpression is a common predictor of LR following treatment for all stages of primary operable ductal carcinoma of the breast. This marker may help in planning optimal treatment and follow-up.

Role of cyclin D1 in ErbB2-positive breast cancer and tamoxifen resistance

Cyclin D1 plays an important role in the regulation of the G1 phase in the cell cycle. In mammary epithelial cells the expression of cyclin D1 is regulated through the oestrogen receptor and via ErbB2 signalling. Here we investigated the prognostic significance of cyclin D1 among 230 breast cancer patients randomised for tamoxifen, CMF chemotherapy and radiotherapy. The importance of combined cyclin D1 and ErbB2 overexpression was also analysed. Immunohistochemical analysis of the cyclin D1 expression resulted in 69 (29.8%) weakly positive, 107 (46.5%) moderately positive and 54 (23.7%) strongly positive cases. The prognostic importance of ErbB2 was significantly greater for patients whose tumours overexpressed cyclin D1 than for other patients (p = 0.026). In the former group, ErbB2 overexpression was strongly associated with increased risk of recurrence (RR = 4.7; 95% CI, 2.1-10.4) and breast cancer death (RR = 5.4; 95% CI, 2.3-12.6). This result is in accordance with experimental studies demonstrating a link between cyclin D1 and ErbB2 in oncogenesis. Among oestrogen receptor positive patients, those with moderate cyclin D1 expression significantly did benefit from tamoxifen treatment (RR = 0.42; 95% CI, 0.21-0.82) whereas those with weak or strong expression did not. Therefore cyclin D1 might be a predictive marker for tamoxifen resistance.

The effect of cyclin D1 (CCND1) G870A-polymorphism on breast cancer risk is modified by oxidative stress among Chinese women in Singapore

Cyclin D1 (CCND1), an intracellular cell-cycle regulatory protein with checkpoint function, can promote cell proliferation or induce growth arrest and apoptosis depending on the cellular context. We hypothesized that the direction of the association between the (CCND1) G870A-polymorphism and breast cancer risk may be modified by dietary and genetic factors influencing the oxidant-antioxidant balance, such as a dietary pattern with a high intake of n-6 fatty acids and a low intake of n-3 fatty acids, or a genetic profile that is deficient in glutathione S-transferases. We tested our hypothesis in a case-control study nested into the Singapore Chinese Health Study, a prospective investigation of diet and cancer in 63,000 Chinese men and women. Genomic DNA collected from 258 incident cases of breast cancer and 670 female cohort controls was examined for CCND1, GSTM1, GSTT1 and GSTP1 genes using fluorogenic 5'-nuclease assay. Unconditional logistic regression models were used to assess the effects with adjustment for potential confounders. All statistical tests were two-sided. The heterozygous CCND1 GA genotype significantly reduced the breast cancer risk in all subjects (OR=0.67, 95% CI 0.45-0.99) when compared with the GG genotype. The association was restricted to women with a high (above median value) intake level of n-6 fatty acids (OR=0.51, 95% CI 0.30-0.87), a low (below median value) intake level of the antagonistic marine n-3 fatty acids (OR=0.54, 95% CI 0.32-0.93) or a total lack of the antioxidative GSTM1 (OR=0.44, 95% CI 0.25-0.80) or GSTT1 genes (OR=0.46, 95% CI 0.24-0.87). The effects were consistently stronger in cases with advanced disease. The AA genotype did not affect breast cancer risk. The results of this study are compatible with the hypothesis that the oxidant-antioxidant balance in cells is an important determinant of the direction of the cyclin D1 effect, leading either to cell proliferation or cell death.

Bases génétiques de la radiosensibilité des cancers du sein

Local-regional radiation therapy is one of the major therapeutic means in the management of breast cancer. Three questions however arise from the important advances achieved in this domain in the past years. The first question concerns the possibilities to identify and overcome the radioresistance of a subset of tumours. The second question is how to recognize women likely to benefit from adjuvant radiation therapy, and therefore to diminish treatment indications in other groups. Finally, the third question is how to identify subjects at high risk for long term injury following breast irradiation, in order to adapt techniques and indications in such populations. The major advances of breast cancer molecular genetics in the past years should provide clinicians with tools to answer these important questions. In this paper, we review the molecular germline (BRCA1, BRCA2, ATM, ...) and somatic (p53, tyrosine kinase receptors, as well as actors of cell cycle, signal transduction, apoptosis, DNA repair ...) main bases of breast cancer radiosensitivity. Recent methods of exploration of the genetic background of both the host and the tumours (gene and protein expression profiles) are also reviewed as major tools of breast cancer management in the next few years.

Association of Cyclin D1 Genotype with Breast Cancer Risk and Survival

Cyclin D1 (CCND1) is a key cell cycle regulatory protein that governs cell cycle progression from the G1 to S phase. A common polymorphism (A870G) in exon 4 of the CCND1 gene produces an alternate transcript (transcript-b) that preferentially encodes a protein with enhanced cell transformation activity and possible prolonged half-life. We evaluated the association of CCND1 A870G polymorphism with breast cancer risk and survival in 1,130 breast cancer cases and 1,196 controls who participated in the Shanghai Breast Cancer Study. Approximately 81% of cases and 79% of controls carried the A allele at A870G of the CCND1 gene [odds ratio, 1.1; 95% confidence interval (95% CI), 0.9-1.4]. As lightly stronger but nonsignificant association was found for the A allele among younger women (odds ratio, 1.3; 95% CI, 0.9-1.8). However, this polymorphism seems to modify the effect of hormonal exposures on postmenopausal breast cancer, as the positive associations of postmenopausal breast cancer with body mass index (Pfor interaction = 0.02) and waist-to-hip ratios (P for interaction &lt; 0.03; all Ps are two sided) were only observed among women who carry the A allele at A870G of the CCND1 gene. Following up with this cohort of patients for an average of 4.84 years, we found that the CCND1 A870G polymorphism was inversely associated with overall and disease-free survival, particularly among women with late stage or estrogen/progesterone receptor-negative breast cancer. The adjusted hazard ratios for disease-free survival associated with GA and AA genotypes were 0.94 (95% CI, 0.49-1.82) and 0.41 (95% CI, 0.19-0.91) for tumor-node-metastasis stage III to IV breast cancer, and 0.35 (95% CI, 0.15-0.80) and 0.32 (95% CI, 0.13-0.79) for estrogen/progesterone receptor-negative breast cancer. This study suggests that CCND1 A870G polymorphism may modify the postmenopausal breast cancer risk associated with hormonal exposure and predict survival after breast cancer diagnosis.

Tissue microarray analyses of G1/S-regulatory proteins in ductal carcinoma in situ of the breast indicate that low cyclin D1 is associated with local recurrence

Ductal carcinoma in situ (DCIS) of the breast constitutes about 10% of all diagnosed breast cancers and, despite surgical removal, it may recur, either as DCIS or invasive breast cancer. Nuclear grade and growth pattern according to Andersen et al as well as surgical margins are factors that have been used to predict local recurrence, but ideally a set of tumour-specific factors should be identified and used as prognostic markers. Many cell cycle regulatory gene products have been shown to be involved in the formation of tumours and are either oncogenes or suppressor genes and involved in key processes in the transformation. We therefore characterised the cell cycle regulators cyclin E, cyclin D1, p27 and p16 in a material of DCIS cases arranged in a tissue microarray. With a manual tissue arrayer, 52% of the initial 177 DCIS samples were successfully targeted allowing immunohistochemical analyses of all four proteins in 92 cases of DCIS. As also observed in invasive breast cancer, there was a trend indicating that DCIS cases with high cyclin D1 were cyclin E low and oestrogen receptor-positive, whereas cyclin E high DCIS cases were cyclin D1 low and oestrogen receptor-negative. For the 64 patients that did not receive postoperative radiotherapy, there were 16 local recurrences (eight DCIS and eight invasive breast cancer) during a mean follow-up time of 63 months. Cyclin E, p27 or p16 were not associated with local recurrence, but interestingly cyclin D1 was significantly and inversely associated with local recurrence, both using univariate and multivariate analyses. In summary, using a tissue array approach we have shown that cyclin D1, besides growth pattern, is a prognostic marker for local recurrence in DCIS.

p53, p16 and cyclin D1: Molecular determinants of radiotherapy treatment response in oral carcinoma

Management of oral cancer by radiotherapy has witnessed promising advances in the past few years, with patient-tailored radio fractionation regimens. Different fractionation schedules, conventional and altered regimes, have been used in curative radiotherapy. Although contribution of biological markers on radio response has been evaluated, its unique influence on various radio fractionation schemes has not been accounted so far. Our study analyses a set of proteins that previously demonstrated radio response influence for their possible prognostic value in decision-making process between the respective fractionation schemes. Expression patterns of regulatory proteins such as p53, cyclin D1, p16, Cdk4, p21, Rb, bcl-2 and PCNA were determined by immunohistochemistry utilizing monoclonal antibodies in 125 patients who received curative radiotherapy dose. Among these 125 patients, 90 (72%) received altered fractionation, whereas 35 (28%) received conventional fractionation. p53 over-expression correlated with local treatment failure among the patients treated with conventional fractionation whereas cyclin D1 over-expression and p16 underexpression were associated with local treatment failure as well as overall survival in altered fractionation treated cases. Our findings suggest that wild-type p53 status may be an important parameter for achieving high local control in those patients undergoing conventional fractionation, where as intact p16 and cyclin D1 status may be beneficial for effective local control in patients who are treated with altered fractionation. Furthermore, it can be assumed that conventional fractionation employs p53-mediated apoptosis, whereas altered fractionation activates the functional G1 cell-cycle checkpoint for tumor growth suppression.

Molecular markers in clinical radiation oncology

Radiation therapy plays a critical role in the management of a majority of patients diagnosed with cancer. Identification of factors that help predict which patients are at risk for relapse within the irradiated field remains an active area of investigation. Although conventional clinical and pathologic factors have been helpful in identifying risk and guiding clinical decision-making for both local and systemic management, there is clearly a need to identify additional prognostic markers, which can aid in refining our treatment strategies and improving outcomes. A substantial amount of research efforts have been devoted to identifying molecular markers for prognostic and therapeutic strategies. The recent emergence of a powerful armamentarium of molecular tools has resulted in rapid expansion of our fund of knowledge and understanding of the molecular biology underlying tumor behavior and response. While a majority of these efforts have been focused on risk factors for metastatic disease and survival, there is a rapidly growing body of literature focused on molecular factors associated with radiation resistance and locoregional failure. In this review, we summarize recent advances and the available literature evaluating molecular markers as they relate to radiation sensitivity of solid tumors. Literature regarding the potential application of expression of genes related to apoptosis, angiogenesis, cell cycle, DNA repair and growth factors will be reviewed. Some of the basic biology and laboratory evidence demonstrating how the marker relates to radiation response and available correlative clinical studies employing these markers as prognostic tools are presented. The majority of molecular markers that have potential clinical significance with respect to radiation sensitivity and local control will be highlighted.

Differential prognostic impact of the cyclins E and B in premenopausal and postmenopausal women with lymph node-negative breast cancer

Searching for new prognostic factors, we investigated the influence of cyclin expression on breast cancer prognosis. A total of 273 archival tumor specimens from patients with pT1/pT2 N0 breast cancers treated by surgery and local irradiation were immunostained for cyclins E, A and B. Outcome was evaluated as metastasis-free (MFS) and disease-specific survival (DSS) over a median observation period of 99 months. In postmenopausal women, DSS was significantly predicted by cyclin E, and in premenopausal patients by cyclin B. No statistical significance was found for cyclin A. When the prognostic impact of cyclins was compared to that of standard prognostic indicators in a multivariate analysis, both cyclin E and cyclin B were selected as independent predictors of survival in postmenopausal and premenopausal patients, respectively. After inclusion of Ki-67 in the model, cyclin E lost its significance, whereas cyclin B remained the only independent prognostic factor with a hazard ratio of 4.5 (p = 0.026) for tumor-related death. Assessment of cyclin expression may, therefore, refine current prognostic models if considered in relation to menopausal status. The prognostic relevance of cyclins is likely attributable to an influence on proliferation, cell survival and genetic instability. Awareness of the molecular mechanisms leading to deregulated cyclin expression may guide decisions for risk-adapted therapy regimens.

Molecular and genetic markers in the local-regional management of breast cancer

The clinical application of molecular markers in the diagnosis, staging, and management of breast cancer continues to expand. Although the use of molecular markers in local-regional disease does not approach the level of their application in the systemic management of breast cancer, a growing body of rature supports the potential for molecular and genetic factors in clinical decision making regarding the local-regional management of breast cancer. As with conventional clinical and histopathologic factors, data regarding molecular and genetic factors as they relate to local-regional relapse may be conflicting and are subject to the usual limitations of predominantly retrospective studies. There are, however, some consistent data suggesting associations between local-regional control of disease and several molecular markers, including hormone receptor status, HER2/neu, p53, proliferative markers, and others. Interpretation of these data and how to use this information in clinical practice remains challenging. The available rature regarding the use of genetic and molecular markers in the local-regional management of breast cancer is summarized in this review.

The molecular basis of radiosensitivity and chemosensitivity in the treatment of breast cancer

The molecular basis of sensitivity to therapeutic radiation and chemotherapy is a complex product of cellular and tissue responses. Certain genetic factors can be highlighted as being of special importance in the response of breast cancers to treatment. The breast cancer susceptibility genes, BRCA1 and BRCA2, determine the phenotype of the tumor, with BRCA1- or BRCA2-deficient tumors showing marked sensitivity to ionizing radiation and drugs that produce double-strand breaks. However, the extent to which loss of BRCA1 or BRCA2 function occurs in sporadic cancer has not yet been determined. The ATM protein plays a significant role in determining the response to therapy, but how frequently the function of ATM is disrupted in breast cancer is debated. Although the p53 protein is a major determinant of the response to ionizing radiation and cytotoxic drugs, there is no consistency in how p53 affects the survival of cells, because an impairment of DNA repair is offset by reduced apoptosis. Growth factors that sustain the proliferation of breast cancer cells may impact the response to therapy by inhibiting apoptosis. Loss of cell-cycle checkpoint responses may result in increased sensitivity, particularly if the checkpoint controls the G2 transition. Overexpression of cyclin D, which shortens the duration of the G1 transition, is associated with mild radiation resistance, perhaps by inhibiting apoptosis. Overall, there is much more to be understood in the complex response of breast cancers to therapy, and many other proteins play important roles in the response to treatment. The focus of our investigation is on those genetic alterations in tumors that affect the response to therapy, which will ultimately allow strategies to achieve therapeutic gain.

Loss of cyclin D1 and p16 expression correlates with local recurrence in nasopharyngeal carcinoma following radiotherapy

BACKGROUND

The cyclin D1/p16/Rb pathway plays a critical role in tumorigenesis and each component of this pathway may be affected in various malignancies. The purpose of this study was to investigate the expression and prognostic significance of these proteins in nasopharyngeal carcinoma (NPC).

PATIENTS AND METHODS

Sixty-five patients undergoing radiotherapy for NPC were analyzed. The expression of cyclin D1, p16 and pRb was evaluated with immunohistochemical analysis of archived pretreatment tumor materials and expression of these proteins was correlated with clinicopathological parameters.

RESULTS

Positive expression of cyclin D1 was observed in 43 of 65 NPCs (66%). p16 and pRb inactivation was identified in 42 of 65 (65%) and four of 65 (6%) tumors, respectively. All but seven tumors (58 of 65, 89%) contained at least one alternation in the cyclin D1/p16/Rb pathway. Loss of cyclin D1 as well as p16 was closely related to local recurrence after radiotherapy for NPC (P = 0.015 and 0.047). No association between pRb expression and clinicopathological outcome was apparent.

CONCLUSIONS

The study's results suggest that the cyclin D1/p16/Rb pathway plays an important role in NPC tumorigenesis. We also find that cyclin D1 and p16 protein levels in NPC may be of use clinically as a predictor of local tumor control.

Association between high initial tissue levels of cyclin d1 and recurrence of nasopharyngeal carcinoma

OBJECTIVES/HYPOTHESIS

Cyclin D1 expression and the rate of apoptosis have been reported to serve as important prognostic indicators in human cancers. The purpose of the present study was to determine the prognostic significance of both initial cyclin D1 expression and the apoptotic index in nasopharyngeal carcinoma.

STUDY DESIGN

Cohort study.

METHODS

Cyclin D1 protein levels and apoptosis in tumors and their corresponding adjacent, histologically normal tissues were determined at the time of initial diagnosis using immunohistochemical staining, Western blot analysis, and in situ end labeling, respectively, in 64 patients with T1-T4/N0-N2, poorly differentiated squamous cell carcinoma of the nasopharynx. All cases were treated by routine radiation therapy with a total median dose of 70 Gy and followed up for 10 years.

RESULTS

High levels of cyclin D1 were found in 35 of 64 tumor specimens (54.7%); no cyclin D1--positive cells were determinable in normal epithelium of the nasopharynx. Rates of early local recurrence (within 5 y) were significantly higher (P <.01) for patients with high levels of cyclin D1 before radiation therapy (24 of 35 patients [68.6%]) as compared with patients with low or no expression (3 of 29 [10.3%]). Furthermore, patients bearing high levels of cyclin D1 had a poorer prognosis concerning 10-year survival than the others (P <.001), whereas overexpression of cyclin D1 did not correlate with the initial TMN classification (P >.05). According to the rate of spontaneous apoptosis in tumors below or above the median, patients were divided into two groups. There was no statistically significant difference for the overall survival between the two groups (P >.05).

CONCLUSIONS

The present study demonstrates that cyclin D1 can be used as an indicator of recurrence and subsequent prognosis in nasopharyngeal carcinoma after radiation therapy. At the same time, the apoptotic state before radiation therapy is of no value in predicting the prognosis of patients with nasopharyngeal carcinoma.