The HDAC6 Inhibitor Tubacin Induces Release of CD133+ Extracellular Vesicles From Cancer Cells.

Tumor-derived extracellular vesicles (EVs) are emerging as an important mode of intercellular communication, capable of transferring biologically active molecules that facilitate the malignant growth and metastatic process. CD133 (Prominin-1), a stem cell marker implicated in tumor initiation, differentiation and resistance to anti-cancer therapy, is reportedly associated with EVs in various types of cancer. However, little is known about the factors that regulate the release of these CD133+ EVs. Here, we report that the HDAC6 inhibitor tubacin promoted the extracellular release of CD133+ EVs from human FEMX-I metastatic melanoma and Caco-2 colorectal carcinoma cells, with a concomitant downregulation of intracellular CD133. This effect was specific for tubacin, as inhibition of HDAC6 deacetylase activity by another selective HDAC6 inhibitor, ACY-1215 or the pan-HDAC inhibitor trichostatin A (TSA), and knockdown of HDAC6 did not enhance the release of CD133+ EVs. The tubacin-induced EV release was associated with changes in cellular lipid composition, loss of clonogenic capacity and decrease in the ability to form multicellular aggregates. These findings indicate a novel potential anti-tumor mechanism for tubacin in CD133-expressing malignancies. J. Cell. Biochem. 118: 4414-4424, 2017. © 2017 Wiley Periodicals, Inc.

BRCA mutations, molecular markers, and clinical variables in early-onset breast cancer: a population-based study.

Early age at onset is generally considered an indicator of genetic susceptibility to breast cancer. To address both the proportion of early-onset breast cancer associated with BRCA-1 or BRCA-2 germline mutation and the contribution of germline mutations to the clinical features and outcome of these tumors, we analyzed molecular status and clinical variables of a population-based sample of 66 Italian women diagnosed with breast cancer before the age of 40 who were unselected for family history. BRCA mutations were screened by automated sequencing of the entire BRCA-1 and BRCA-2 coding regions and splice junctions. Twenty-eight late-onset (over 45 years), sporadic, breast cancers were designated as "control group" for comparisons with early-onset cases. BRCA mutations (10 BRCA-1 and 6 BRCA-2) were detected in 15 (22.7%) out of 66 tested patients. The combination of ER, PR, HER-2/neu negativity and p53 positivity was significantly more frequent in BRCA-1 positive tumors than in BRCA-2 positive and non-BRCA tumors (P=0.03). Taken collectively, BRCA-positive tumors correlated with high histologic grade and ER negativity compared with non-BRCA and sporadic tumors (P=0.05 and 0.003, respectively). There were no significant differences between BRCA-associated breast cancers (BABC) and non-BABC in relapse-free, event-free, and overall survival. Our data confirm that the combination of age at onset and tumor phenotype can provide an efficient model for identifying individuals with a high probability of carrying BRCA mutations and support the hypothesis that breast cancer in BRCA carriers is qualitatively distinct from other early-onset breast cancers and from late-onset, sporadic, breast carcinomas. Further studies on incident cases are necessary to define the independent prognostic significance of germline BRCA mutations.

The changing distribution and survival of colorectal carcinoma: an epidemiological study in an area of northern Italy.

OBJECTIVE: This study analyses the inter-relations of anatomical tumour location, gender, age and incidence rates for colorectal cancer from 1978 to 1999 in an area of northern Italy: the Parma district. METHODS: Data were obtained from the Parma Cancer Registry. Age-adjusted incidence rates were analysed by gender, age and colorectal cancer subsites. In addition, 5 year observed survival rates were determined. RESULTS: In the Parma area, the incidence of colorectal cancer is rising. We have observed a true increase in the rate of the age standardized incidence of right colon cancer, linked to an increased incidence of left colon cancer, while the incidence of rectal cancer has remained constant. The frequency of right-sided colon cancer was higher in aged patients, and in women. Age-standardized relative survival of patients after diagnosis of colorectal cancer between 1992 and 1996 was found to be significantly higher than age-standardized relative survival after diagnosis between 1978 and 1982. CONCLUSIONS: In the Parma area there has been an increased incidence of right colon cancer, linked to an increased incidence of left colon cancer, while the incidence of rectal cancer has remained constant. We feel that this shift, whatever the reason for it, has important implications for the choice of screening techniques.

Molecular profile and clinical variables in BRCA1-positive breast cancers. A population-based study.

PURPOSE: To evaluate the clinical features of breast cancer patients with genetic susceptibility to this disease and to investigate the contribution of BRCA1 germline mutations to the phenotype of these tumors. PATIENTS AND METHODS: We reviewed the clinical and pathological records of 102 women with suspected inherited susceptibility to breast cancer consecutively seen at the Genetic Oncology Service of Parma, Italy. Sixty-two patients with a high probability of harboring a germline, cancer-predisposing mutation were tested for BRCA1 mutations. Exon 11 was screened using the protein truncation test and detected mutations were confirmed by direct sequencing (DS). All other exons were analyzed by DS. RESULTS: Among the 62 patients with a completed mutation analysis, 48 (77.4%) had wild-type BRCA1, six (9.6%) had variants of unclear significance, eight (13%) had deleterious mutations. BRCA1-associated breast cancers (BABC) were significantly less likely to be diagnosed at stage I than breast cancers in women without mutations (12.5% vs 51%; P = 0.045), more likely to have a high proliferation rate (100% vs 24%, P < 0.001), and more likely to be histological grade 3 (100% vs 14%, P < 0.001), estrogen and progesterone receptor negative (87.5% vs 13%, P < 0.001; 75% vs 23%, P = 0.004), and p53 positive (87.5% vs 30%, P = 0.023). All tumors with BRCA1 mutations were HER-2/neu negative compared with 57% of the non-BRCA1 tumors (P = 0.04). There were no significant differences between BABC and non-BABC in 20-year relapse-free survival, 20-year event-free survival, and 20-year overall survival. CONCLUSION: In this population-based study, BABC seems to present with adverse molecular features when compared with non-BABC, although the prognosis appears to be similar.

A breast cancer patient from Italy with germline mutations in both the BRCA1 and BRCA2 genes.

We report the first case in Italy of a non-Ashkenazi double heterozygote for BRCA1 and BRCA2 genes. This finding is predictably rare, with a maximum frequency of 1/250,000. The proband and her mother were diagnosed with early-onset breast cancer. No other relatives with breast and/or ovarian cancer were observed. The implications of this case in regard to genetic testing and counseling are substantial.