Cyclin D1 protein overexpression and gene amplification in benign breast tissue and breast cancer risk

Analysis of CCND1 protein and circulatory antioxidant enzyme activity association in oral squamous cell carcinoma

Antioxidants are involved in the process of cellular damage prevention, which is considered as an avenue for cancer development. Free radicals are produced in the body upon exposure to stress, cigarette smoke, alcohol, toxins found in personal care products, pesticides in foods, radiation from the sun, viruses, germs or fungi etc. CCND1/CyclinD1 protein was found to be overexpressed in Oral squamous cell carcinoma. One hundred patients with oral squamous cell carcinoma were recruited along with hundred controls for this study from MNJ institute of Oncology with the approval of Ethics Committee, 5 ml blood samples were collected from each patient and centrifuged to collect serum for various assays. The antioxidant enzymes like catalase, SOD, GPX and GST were estimated using enzymatic assays. Results were expressed as unit of activity for mg of protein. Insilco analysis is performed using STRING v 11 Protein interaction tool. The patients with oral cancer had significantly reduced activities of SOD, GST and GPX (1.49 ± 0.49, 3.97 ± 0.86 and 10.7 ± 0.73 respectively) compared to healthy controls (4.37 ± 1.43, 6.10 ± 1.12 and 13.8 ± 1.25 respectively) (p < 0.005). However no significant difference was observed with regard to catalase activity (2.71 ± 6.51 and 4.03 ± 1.48) (p = 0.28). The proteins interaction PPI enrichment p-value was found to be 3.22e-10 predicted significantly more interactions. Our research findings shown that there was a decline in activity of superoxide dismutase, glutathione peroxidase and glutathione s transferase in addition, personal habits like smoking play a major role in the development and progression of oral carcinogenesis and based on Insilco analysis results CCND1/Cyclin D1 could be the potential therapeutic target in oral squamous cell carcinoma.

Thiocoraline mediates drug resistance in MCF-7 cells via PI3K/Akt/BCRP signaling pathway

Thiocoraline, a depsipeptide bisintercalator with potent antitumor activity, was first isolated from marine actinomycete Micromonospora marina. It possesses an intense toxicity to MCF-7 cells at nanomolar concentrations in a dose-dependent manner evaluated by MTT assay and crystal violet staining. We established a human breast thiocoraline-resistant cancer subline of MCF-7/thiocoraline (MCF-7/T) to investigate the expression variation of breast cancer resistance proteins (BCRP) and its subsequent influence on drug resistance. Colony-forming assay showed that the MCF-7 cells proliferated faster than the MCF-7/T cells in vitro. Western blot analysis demonstrated that thiocoraline increased the phosphorylation of Akt. Additionally, the sensitivity of tumor cells to thiocoraline was reduced with a concurrent rise in phosphorylation level of Akt and of BCRP expression.These studies indicated that thiocoraline probably mediated the drug resistance via PI3K/Akt/BCRP signaling pathway. MK-2206 dihydrochloride, a selective phosphorylation inhibitor of Akt, significantly decreased MCF-7 cell viability under exposure to thiocoraline compared to the control. However, it was not obviously able to decrease MCF-7/T cell viability when cells were exposed to thiocoraline.

CCND1 G870A polymorphism contributes to breast cancer susceptibility: a meta-analysis

Cyclin D1 (CCND1), a key cell cycle regulatory protein that governs the cell cycle progression from G1 to S phase, can promote cell proliferation or induce growth arrest and apoptosis. Since the identification of a well-characterized functional polymorphism, G870A in exon 4 of CCND1, several molecular epidemiological studies were conducted in recent years to evaluate the association between G870A and breast cancer risk in diverse populations. However, the results remain conflicting rather than conclusive. This meta-analysis on 5,371 cases with breast cancer and 5,336 controls from 7 published case-control studies showed that the variant allele 870A was associated with a significantly increased risk of breast cancer (AA vs. GG: OR = 1.18, 95% CI = 1.06-1.32; AG vs. GG: OR = 1.12, 95% CI = 1.01-1.23; AA/AG vs. GG: OR = 1.14, 95% CI = 1.04-1.25) without any between-study heterogeneity. In the stratified analysis by race, we found that the increased breast cancer risk associated with G870A polymorphism was more evident in Caucasians (OR = 1.14, 95% CI = 1.01-1.28, P = 0.88 for heterogeneity test), but not significant in Asians (OR = 1.10, 95% CI = 0.85-1.42, P = 0.05 for heterogeneity test). The results suggest that CCND1 G870A polymorphism may contribute to breast cancer development, especially in Caucasians. Additional well-designed large studies were required for the validation of this association in different populations.

Molecular biomarkers for cancer detection in blood and bodily fluids

Cancer is a major and increasing public health problem worldwide. Traditionally, the diagnosis and staging of cancer, as well as the evaluation of response to therapy have been primarily based on morphology, with relatively few cancer biomarkers currently in use. Conventional biomarker studies have been focused on single genes or discrete pathways, but this approach has had limited success because of the complex and heterogeneous nature of many cancers. The completion of the human genome project and the development of new technologies have greatly facilitated the identification of biomarkers for assessment of cancer risk, early detection of primary cancers, monitoring cancer treatment, and detection of recurrence. This article reviews the various approaches used for development of such markers and describes markers of potential clinical interest in major types of cancer. Finally, we discuss the reasons why so few cancer biomarkers are currently available for clinical use.

Tumor susceptibility and prognosis of breast cancer associated with the G870A polymorphism of CCND1

We aimed to investigate the role of CCND1 G870A polymorphism genetic and transcriptomic effects susceptibility in association with breast cancer carcinogenesis and clinical prognosis. A case-control study was conducted with the enrollment of 992 sporadic breast cancer patients and the corresponding 960 normal controls from routine mammographic or sonographic screening for breast cancer between 1995 and 2003 in Taiwan. The 167 fragment spanning the G870A polymorphism in exon 4-intron 4 boundary was amplified to identify genotype of CCND1 (G870A) polymorphism. Competitive RT-PCR were further performed to investigate alternative transcript in four different specimens in association with immunohistochemistry markers. The results showed that AG and AA subgroup were at increased risk for developing breast cancer compared with the GG genotype by 19% (OR 1.19 (0.85-1.67)) and by 34% (OR 1.34 (0.04-1.74)), respectively. A870 allele revealed a recessive tendency while GG and AA/AG subgroup was compared (OR 1.35 (1.07-1.70)). AA genotype also had a higher risk in premenopausal women than postmenopausal ones. The recurrence-free survival was longer in patients with GG+AG than that in patients with AA (P = 0.034). A870 allele produced more transcript b both in malignant. There were significant correlations between several immunohistochemistry markers (such as Ki-67) and cyclin D1 or CDk4. We concluded CCND1 G870A polymorphism make significant contribution to breast cancer in the country with the preponderance of breast cancer in young women. The role of G870A polymorphism in alternative transcript was not only implicated in CCND1 alternative splicing but also correlated with immunohistochemistry markers.

Correlation of gamma-catenin expression with good prognosis in medulloblastomas

OBJECT

Medulloblastoma is a malignant cerebellar tumor of childhood and is difficult to cure due to frequent cerebrospinal fluid dissemination. Amplification of the c-myc gene (4%) and messenger (mRNA) overexpression (50%) are known to be adverse prognostic indicators. Because mRNA overexpression cannot be explained by gene amplification alone, mechanisms other than gene amplification are postulated. Molecules on the Wnt signal pathway in primary tumors were examined.

METHODS

Immunohistochemical and cytogenetic examinations of beta- and gamma-catenin, c-myc, N-myc, and cyclin D1 in 24 primary medulloblastomas were conducted, and their clinical relevance was evaluated. Cytoplasmic/membranous staining of beta- and gamma-catenin was detected in 19 (79%) and nine (37%) cases, respectively, and nuclear expression of cyclin D1 and c-myc was detected in six (25%) and 21 (83%) cases, respectively. The expression levels of gamma-catenin in Western blot analysis and immunohistochemistry were similar. By differential polymerase chain reaction, c-myc and N-myc were amplified separately in two large cell/anaplastic medulloblastomas. No cyclin D1 amplification, or beta- or gamma-catenin mutations were found. Kaplan-Meier analysis revealed no dissemination at diagnosis (Chang Grade M0) and gamma-catenin expression was correlated with good prognosis (p = 0.0002 and 0.003, respectively). Expression of gamma-catenin was also significant in the M0 group (p = 0.022). Expression of cyclin D1 showed a trend toward adverse outcome (p = 0.057) and all patients in whom cyclin D1 expression was found died of disease.

CONCLUSIONS

Expression of gamma-catenin is of great prognostic value and its immunohistochemistry may be useful for further stratification of treatment. Cyclin D expression may have the potential to be an adverse prognostic indicator.

Benign breast disease and the risk of breast cancer

BACKGROUND

Benign breast disease is an important risk factor for breast cancer. We studied a large group of women with benign breast disease to obtain reliable estimates of this risk.

METHODS

We identified all women who received a diagnosis of benign breast disease at the Mayo Clinic between 1967 and 1991. Breast-cancer events were obtained from medical records and questionnaires. To estimate relative risks, we compared the number of observed breast cancers with the number expected on the basis of the rates of breast cancer in the Iowa Surveillance, Epidemiology, and End Results registry.

RESULTS

We followed 9087 women for a median of 15 years. The histologic findings were nonproliferative lesions in 67 percent of women, proliferative lesions without atypia in 30 percent, and atypical hyperplasia in 4 percent. To date, 707 breast cancers have developed. The relative risk of breast cancer for the cohort was 1.56 (95 percent confidence interval, 1.45 to 1.68), and this increased risk persisted for at least 25 years after biopsy. The relative risk associated with atypia was 4.24 (95 percent confidence interval, 3.26 to 5.41), as compared with a relative risk of 1.88 (95 percent confidence interval, 1.66 to 2.12) for proliferative changes without atypia and of 1.27 (95 percent confidence interval, 1.15 to 1.41) for nonproliferative lesions. The strength of the family history of breast cancer, available for 4808 women, was a risk factor that was independent of histologic findings. No increased risk was found among women with no family history and nonproliferative findings. In the first 10 years after the initial biopsy, an excess of cancers occurred in the same breast, especially in women with atypia.

CONCLUSIONS

Risk factors for breast cancer after the diagnosis of benign breast disease include the histologic classification of a benign breast lesion and a family history of breast cancer.

Cyclin D1 is overexpressed in atypical teratoid/rhabdoid tumor with hSNF5/INI1 gene inactivation

OBJECT

Although atypical teratoid/rhabdoid tumor (AT/RT) is known to generate through inactivation of the hSNF5/INI1 gene on chromosome 22q, the downstream molecular mechanism remains unclear. We histologically and molecularly reviewed our pediatric brain tumors for unrecognized AT/RTs and evaluated the role of cyclin D1, a potential molecular target of hSNF5/INI1.

METHODS

We analyzed 16 tumors under three years of age: seven medulloblastomas, three anaplastic ependymomas (E IIIs), two each of supratentorial primitive neuroectodermal tumors (sPNETs) and choroid plexus carcinomas (CPCs), and one each of neuroblastoma and pineoblastoma. Immunohistochemistry for glial fibrillary acidic protein, vimentin, epithelial membrane antigen, smooth muscle actin and cyclin D1 was performed. Polymerase chain reaction (PCR)-single-strand conformation polymorphism analysis with direct sequencing, differential PCR and microsatellite analysis were conducted for hSNF5/INI1mutation, homozygous deletion and loss of heterozygosity (LOH) on 22q, respectively. Because of the presence of rhabdoid cells and the polyimmunophenotypic features, the diagnosis was revised to AT/RT in five (31%) tumors, namely, two E IIIs and one each of medulloblastoma, CPC and pineoblastoma. Three of them harbored such hSNF5/INI1 aberrations as germline single base deletion (492/6 delC) and missense mutation (C157T) together with LOH 22q or homozygous deletion. Cyclin D1 was overexpressed in those three tumors but not in the two that lacked hSNF5/INI1 inactivation.

CONCLUSION

AT/RT can be misdiagnosed as a variety of tumors, including ependymoma that potentially harbors LOH 22q. Our data indicate that cyclin D1 is a target of hSNF5/INI1in primary tumors.

Expression of cyclins E, A, and B, and prognosis in lymph node-negative breast cancer

Unexpected outcomes in breast cancer demand a refinement of prognostic criteria. This study therefore investigated the prognostic relevance of cyclin expression in a cohort of 332 T1-T2 N0 infiltrating ductal carcinomas with long-term follow-up (median 99 months). By univariate analysis, tumour size, histopathological grade, hormone receptor content, cyclin E, cyclin B, and the Ki-S5 (Ki-67) index significantly predicted disease-specific and metastasis-free survival. Cyclin A did not achieve statistical significance. In a multivariate analysis, both cyclin E [relative risk (RR) 2.01, p = 0.021] and cyclin B (RR 1.85, p = 0.033) were selected as independent prognosticators of metastasis-free survival when the Ki-67 index was omitted, but only cyclin E expression was associated with disease-specific survival (RR 2.56, p = 0.006). When Ki-67 was included as a covariate, cyclin E lost its significance with respect to disease-specific survival but remained significant for metastasis-free survival. In an analogous analysis including Ki-67, the number of concurrently overexpressed cyclins did not attain statistical significance regarding disease-specific survival but was selected as the leading predictor of metastatic disease. It is concluded that combined overexpression of cyclins may imply genetic instability enhancing metastatic potential, but that survival ultimately depends on the proliferative activity of tumour cells.

Cancer Biomarkers: Easier Said Than Done

Background: Biological and technical advances have led to greatly increased research and development of cancer biomarkers. This overview lists some of the challenges and barriers to developing novel effective cancer biomarkers and enablers to facilitate cancer biomarker development.

Methods: Current scientific literature regarding development of biomarkers for cancer and other diseases was reviewed.

Results: Challenges to developing cancer biomarkers include better understanding of biological heterogeneity, including host/tumor heterogeneity; analytical factors, such as interferences and analytical sensitivity; clinical pathologic factors, such as current histopathologic standards; and health service and market factors. More standardized biomarker definitions, standardization of cancer biology terminology, and high-quality reference materials (specimen and clinical data repositories) were identified as factors required to support advances in cancer biomarkers.

Conclusions: With the above enablers, novel cancer biomarkers may be useful, both for assessing early and established neoplasia more precisely and for contributing data toward development of novel practical concepts regarding cancer biology.