Differences in prognosis and efficacy of chemotherapy by p53 expression in triple-negative breast cancer.

PURPOSE: TP53 mutation is the most common mutation in breast cancer, and it is considered a target marker of triple-negative breast cancer (TNBC). We investigated whether expression of p53 detected by immunochemical staining predicts the chemotherapy response of TNBC. METHODS: A total of 11,393 TNBC patients who had between stage I and stage III enrolled in the Korean Breast Cancer Society Registry database from January 1, 2000 to December 31, 2015. There were 6,331 'p53-positive (+) TNBC' patients and 5062 'p53-negative (-) TNBC' patients. RESULTS: In univariate analysis, p53(+) TNBC had a worse prognosis than p53(-) TNBC in patients not receiving chemotherapy (P = 0.003). However, there was no difference in prognosis between p53(+) TNBC and p53(-) TNBC for patients receiving chemotherapy. In multivariate analysis adjusted for age and stage, the risk of p53(+) TNBC was 1.84 times higher than that of p53(-) TNBC in the non-chemotherapy group. However, there was no difference between p53(+) TNBC and p53(-) TNBC in patients receiving chemotherapy. In p53(+) TNBC, the risk was 0.6-fold lower when chemotherapy was administered than when chemotherapy was not administered. However, in p53(-) TNBC, there was no risk reduction effect by chemotherapy. CONCLUSION: The prognosis of p53(+) TNBC has worse than p53(-) TNBC, but the risk for survival was significantly reduced with chemotherapy. It suggests that p53(+) TNBC would be more sensitive to chemotherapy than p53(-) TNBC.

Selective production of epothilone B by heterologous expression of propionyl-CoA synthetase in Sorangium cellulosum.

The metabolic engineering of epothilones, as secondary metabolites, was investigated using Sorangium cellulosum to achieve the selective production of epothilone B, a potent anticancer agent. Thus, the propionyl-CoA synthetase gene (prpE) from Ralstonia solanacearum was heterologously expressed in S. cellulosum to increase the production of epothilone B. Propionyl-CoA synthetase converts propionate into propionyl-CoA, a potent precursor of epothilone B. The recombinant S. cellulosum containing the prpE gene exhibited a significant increase in the resolution of epothilones B/A, with an epothilone B to A ratio of 127 to 1, which was 100 times higher than that of the wild-type cells, demonstrating its potential use for the selective production of epothilone B.

The pattern of gene copy number changes in bilateral breast cancer surveyed by cDNA microarray-based comparative genomic hybridization.

The nature of genetic alterations in bilateral breast cancer (BBC) associated with the distinctive development of a second primary tumor or a metastatic lesion is not clearly established. In this study, patterns of promoter methylation and gene copy number changes were assessed for their utility in the distinction of two types of BBC (synchronous and metachronous). Seven cases of synchronous and five cases of metachronous breast cancer tissues were used in X chromosome inactivation assay to assess the methylation pattern of human androgen receptor gene. X chromosome inactivation assay alone did not provide enough information to distinguish the genetic origins of synchronous and metachronous BBC. When four pairs of paraffin-embedded BBC tissues were used in cDNA array-based CGH with placenta DNA as a reference, higher DNA copy number changes were observed from metachronous pairs (9.0%) than from synchronous pairs (3.1%). From the two cases of metachronous pairs tested, 44 genes were found to be commonly modulated in gene copy numbers in a cancer detected later.

The efficacy of acrylic acid grafting and arginine-glycine-aspartic acid peptide immobilization on fibrovascular ingrowth into porous polyethylene implants in rabbits.

PURPOSE: To determine the effects of acrylic acid (AA) grafting by argon plasma treatment and of immobilization of arginine-glycine-aspartic acid (RGD) peptides on fibrovascular ingrowth rate into high-density porous polyethylene (HPPE) anophthalmic orbital implants. MATERIALS AND METHODS: Sixty rabbits were divided into three groups, with 20 rabbits in each group: (1) control group, rabbits implanted with unmodified HPPE; (2) PAA group, rabbits implanted with HPPE grafted with poly(AA) by argon plasma treatment; (3) RGD group, rabbits implanted with HPPE grafted with AA by argon plasma treatment and subsequently immobilized with RGD peptide. An HPPE spherical implant was put in the abdominal muscles of rabbit. After implantation for 4 weeks, the retrieved implants were sectioned and stained with hematoxylin and eosin (H&E). Blood vessels were counted using CD-31 immunostaining. Cross-sectional areas of fibrovascular ingrowth, blood vessel densities, and host inflammatory response scores were determined for all three groups. RESULTS: The mean cross-sectional areas of fibrovascularization at 2 and 3 weeks after implantation were the greatest in the RGD group, followed by the PAA group. While minimal fibrovascular ingrowths were noted in all implants at 1 week, all the implants showed nearly complete ingrowth at 4 weeks. Blood vessel densities were the highest in the RGD group, followed by the PAA group at 2, 3, and 4 weeks. The mean inflammation scores of the PAA and RGD groups were less than that of the control group. CONCLUSION: Fibrovascularization into HPPE implants was enhanced by surface grafting of AA and further improved by immobilizing RGD peptides onto the grafted AA surfaces. The inflammatory reactions were mild by either technique of surface modification.