Genomic profiling of breast cancer

Helioxanthin suppresses the cross talk of COX-2/PGE2 and EGFR/ERK pathway to inhibit Arecoline-induced Oral Cancer Cell (T28) proliferation and blocks tumor growth in xenografted nude mice

Helioxanthin, an active compound from Taiwania cryptomerioides Hayata, has been shown to have various biological activities. However, their anticancer effect in oral squamous cell carcinoma has not been well established yet. Helioxanthin inhibited the proliferation of oral squamous cell carcinoma cells in a dose-dependent manner by inducing G2/M phase arrest. Similarly, helioxanthin inhibited cyclooxygenase-2, (COX-2), phosphorylated EGFR, and extracellular-signal-regulated kinases (ERK) protein level and further reduced the nuclear accumulation of phosphorylated epidermal growth factor receptor (pEGFR) and activator protein-1(AP-1) family protein, c-fos. Moreover, helioxanthin at the dose of 20 and 30 mg kg^-1 for 15 days reduced the tumor growth in animal model. This study demonstrated that Helioxanthin exerts its anticancer activity against oral cancer cells by downregulating EGFR/ERK/c-fos signaling pathway to inhibit COX-2 level and by activating cyclin-dependent kinase inhibitor (p27) to further induce G2/M cell cycle arrest. This helioxanthin may serve as a novel candidate for oral cancer prevention. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 2045-2056, 2016.

Combined effect of menopause age and genotype on occurrence of breast cancer risk in Pakistani population

Cancer incidences and mortality rates are rapidly increasing and breast cancer is among the most frequent malignancy experienced in women worldwide. The occurrence of breast cancer could be associated with various social, cultural, environmental, life-style, hormonal and genetic factors.

OBJECTIVE

To establish if PvuII and XbaI polymorphisms of estrogen receptor alpha would make Pakistani women more susceptible to breast cancer. Furthermore, association between breast cancer and various factors was also explored to establish the contributing factors in breast cancer in Pakistani population.

SUBJECTS AND METHODS

Two hundred samples, aged 15-65 years, consisting of 100 breast cancer patients and 100 control samples were ascertained for this case-control study in order to evaluate the factors related to disease incidence. 5-7 ml of blood sample of each participating women in the study was collected and analyzed for polymorphisms of PvuII and XbaI using PCR-RFLP method.

RESULTS

The menopause had strong influence on incidences of cancer with ca 18-fold increase in risk of breast cancer in women with menopause compared with non-menopaused. Furthermore significant impact of menopause age (P<0.0001) was observed on the incidence of cancer, as high rate of cancer incidence was observed in patients with age between 36 and 45 years (P<0.0001). Similarly, the genotype XbaI had significant influence on the incidence of the disease with heterozygous genotype of XbaI was 45% higher than wild type in cancerous cases. The menopausal women having heterozygous and homozygous mutants of PvuII or XbaI genotypes were strongly correlated with breast cancer (P<0.01).

CONCLUSION

The polymorphism of genes involving estrogen-metabolizing pathway and estrogen receptor pathway may play an important role in the etiology of breast cancer in Pakistani women.

Expression of Ki-67 and p27(Kip1) in fine-needle aspirates from breast carcinoma and benign breast diseases

Cell atypia in breast fine needle aspiration (FNA) can introduce some diagnostic difficulties. Molecules reflecting proliferative cell potential, such as Ki-67 and p27(Kip1) , can help in recognizing the true biological nature of a cell. Thus, the objective of the study was to analyze the difference in Ki-67 and p27(Kip1) cell immunoexpression in breast FNA specimens between fibroadenomas, fibrocystic changes (FCC) with atypia, and breast carcinoma. Microscopic analyses of cell cytomorphology and Ki-67 and p27(Kip1) breast cell immunoexpression were done after standard Pappenheim and immunocytochemical staining (labeled streptavidin-biotin, LSAB) method in autostainer DakoCytomation TechMate™. The study included 50 patients with breast carcinoma, 20 patients with fibroadenoma, and 20 patients with FCC with atypia. High Ki-67 and low or absent p27(Kip1) were found in most patients with breast carcinoma, while majority of FCC with atypia were characterized by low Ki-67 and moderate to high p27(Kip1) cell immunoexpression. Majority of fibroadenomas were associated with low Ki-67 and low to moderate p27(Kip1) cell immunoexpression indicating progressive decrease in cell cycle inhibition, but still not so high proliferative activity as in carcinoma. However, although statistically significant difference for Ki-67 and p27(Kip1) was found between breast lesions in our study, the large ranges observed for each marker make them essentially useless for better cytological diagnosis in a single case. Regarding their opposite role in cell cycle, inverse correlation of Ki-67 and p27(Kip1) was noticed. Poorly differentiated carcinoma cells had mostly high Ki-67 and low p27(Kip1) cell immunoexpression.