Screening mutations in miRNA196a2 and miRNA148a in Vietnamese breat cancer patients

Breast cancer, affecting women mostly, is the second common cancer in the world. Previous studies showed that miRNAs played a role in the regulation of signal transduction pathways in many different stages of cancer. The SNPs that occur on miRNA can have broad impact in cancer by many different ways. It was found that SNP rs11614913 C>T in miR-196a2 related to breast cancer risk in Asia. In addition, the association between SNP rs6977848 T> G in miR-148a and breast cancer have early proven on the Australian. In this study, a combination of Tetra-Arms-PCR and PCR product melting analysis,was used to screen for the presence of the allele of rs11614913 and rs6977848 in Vietnamese breast cancer patients. The results showed that the frequency of C and T allele ofrs11614913 were 58.96 % and 41.04 % respectively; the frequency of T and G allele of rs6977848 were 99 % and 1 %, respectively. Based on the genotype frequencies in the HapMap, rs11614913 is predicted to be associated with breast cancer while rs6977848 is probably not related to breast cancer in Vietnam due to a highly dominant frequency of only one type allele. However, there is still need for further research on a larger sample size to confirm the association between the two SNPs with breast cancer in Vietnam.

Genomic profiling of early-onset and hereditary breast cancer.

30 Background: Worldwide, breast cancer is the most common cancer in women. Susceptibility is thought to be polygenic and the risk tends to increase in women with positive family history of breast cancer. Methods: We proposed an ambitious Middle Eastern-based study that entailed exome sequencing of approximately 50 women from the Middle East (M.E) with moderate family history of any cancer. DNA from tumor samples with matching lymphocytes from the same subjects and 50 normal Middle Eastern women without history of familial or sporadic cancers in the family, were subjected to whole-exome sequencing on the HiSeq 1000/2000 Illumina platforms to map major breast cancer–activating genetic defects. Results: Several unique to the M.E region and novel germline mutations in non-BRCA1/2 genes were identified in this cohort. Germline mutations in TP-53, BARD1 and mismatch repair genes were more frequent than expected by chance. More importantly, the breast cancers showed interesting copy number and mutations variants that may aid our understanding of breast cancer initiations. Conclusions: The M.E. breat cancer may be caused by a unique set of germline variants and that the M.E breast cancers may represent an entity that may aid in our understanding of this common disease.

Can surgery provoke the outgrowth of latent breast cancer? A unifying hypothesis

To explain bimodal relapse patterns, we have previously suggested that metastatic breast cancer growth commonly includes periods of temporary dormancy at both the single cell and avascular micrometastasis phases (with 1 year and 2 year half-lives respectively). We further suggested that primary surgery sometimes initiates growth of distant dormant disease accelerating relapse. These iatrogenic events are common in that they occur in over half of all relapses. Surgery induced angiogenesis is mostly confined to premenopausal node positive patients in which case 20% of patients are so affected. We review here how this hypothesis explains a vairety of previously unrelated breast cancer phenomenon including 1) the mammography paradox for women age 40–49 untreated with adjuvant therapy, 2) the particularly high benefit of adjuvant chemotherapy for premenopausal node positive patients, 3) the heterogeneity of breast cancer, 4) the aggressiveness of cancer in young women, 5) the outcome differences with timing of surgery within the menstrual cycle, 6) the common myths regarding cancer spreading “when the air hits it” and treatment “provoking” the tumor, 7) the excess mortality of blacks over whites, and 8) reports from physicians 2000 years ago. In parallel to physicists who have long sought to explain all of physics with a unified field theory, we now suggest temporary dormancy together with surgery induced tumor growth provides a unifying theory for much of breat cancer.