BRCAness Predicts Resistance to Taxane-Containing Regimens in Triple Negative Breast Cancer During Neoadjuvant Chemotherapy

AbstractBackgroundTo provide optimal treatment of heterogeneous triple negative breast cancer (TNBC), we need biomarkers that can predict the chemotherapy response.Patients and MethodsWe retrospectively investigated BRCAness in 73 patients with breast cancer who had been treated with taxane- and/or anthracycline-based neoadjuvant chemotherapy (NAC). Using multiplex, ligation-dependent probe amplification on formalin-fixed core needle biopsy (CNB) specimens before NAC and surgical specimens after NAC. BRCAness status was assessed with the assessor unaware of the clinical information.ResultsWe obtained 45 CNB and 60 surgical specimens from the 73 patients. Of the 45 CNB specimens, 17 had BRCAness (38.6% of all subtypes). Of the 23 TNBC CNB specimens, 14 had BRCAness (61% of TNBC cases). The clinical response rates were significantly lower for BRCAness than for non-BRCAness tumors, both for all tumors (58.8% vs. 89.3%, P = .03) and for TNBC (50% vs. 100%, P = .02). All tumors that progressed with taxane therapy had BRCAness. Of the patients with TNBC, those with non-BRCAness cancer had pathologic complete responses significantly more often than did those with BRCAness tumors (77.8% vs. 14.3%, P = .007). After NAC, the clinical response rates were significant lower for BRCAness than for non-BRCAness tumors in all subtypes (P = .002) and in TNBC cases (P = .008). After a median follow-up of 26.4 months, 6 patients—all with BRCAness—had developed recurrence. Patients with BRCAness had shorter progression-free survival than did those with non- BRCAness (P = .049).ConclusionIdentifying BRCAness can help predict the response to taxane, and changing regimens for BRCAness TNBC might improve patient survival. A larger prospective study is needed to further clarify this issue

A Case of Androgen Receptor-positive Triple Negative Breast Cancer with Good Response to Anti-androgen Therapy

Anti-androgen therapy has been proposed to be effective in the treatment of androgen receptor (AR)-positive triple negative breast cancer (TNBC). Herein, we report on the case of a 91-year-old female patient with AR-positive TNBC who underwent anti-androgen therapy and had a good response. Because of dementia, the patient lives in an aged care facility. It was here that a staff member noticed a mass with a rash on the patient\u27s breast. Consequently, the patient was sent for further examination. Ultrasonography revealed an irregularly shaped, indistinct hypoechoic mass measuring 19×18×9mm located in the upper outer quadrant of the left breast. Core needle biopsy (CNB) was performed and the mass was diagnosed as apocrine carcinoma. Further immunohistochemical analysis showed that the mass was AR-positive TNBC. Anti-androgen therapy was determined to be the optimal treatment option for this patient. The Institutional Review Board approval the off-label use of an anti-androgen for the treatment of this patient, who was subsequently treated with the anti-androgen flutamide. After 8 months, the size of the tumor had reduced to 15×9×5mm

Essential roles of class E Vps proteins for sorting into multivesicular bodies in Schizosaccharomyces pombe

The multivesicular body (MVB) sorting pathway is required for a number of biological processes, including downregulation of cell-surface proteins and protein sorting into the vacuolar lumen. The function of this pathway requires endosomal sorting complexes required for transport (ESCRT) composed of class E vacuolar protein sorting (Vps) proteins in Saccharomyces cerevisiae, many of which are conserved in Schizosaccharomyces pombe. Of these, sst4/vps27 (homologous to VPS27) and sst6 (similar to VPS23) have been identified as suppressors of sterility in ste12Δ (sst), although their functions have not been uncovered to date. In this report, these two sst genes are shown to be required for vacuolar sorting of carboxypeptidase Y (CPY) and an MVB marker, the ubiquitin–GFP–carboxypeptidase S (Ub–GFP–CPS) fusion protein, despite the lack of the ubiquitin E2 variant domain in Sst6p. Disruption mutants of a variety of other class E vps homologues also had defects in sorting of CPY and Ub–GFP–CPS. Sch. pombe has a mammalian AMSH homologue, sst2. Phenotypic analyses suggested that Sst2p is a class E Vps protein. Taken together, these results suggest that sorting into multivesicular bodies is dependent on class E Vps proteins, including Sst2p, in Sch. pombe

An analytical platform for mass spectrometry-based identification and chemical analysis of RNA in ribonucleoprotein complexes

We describe here a mass spectrometry (MS)-based analytical platform of RNA, which combines direct nano-flow reversed-phase liquid chromatography (RPLC) on a spray tip column and a high-resolution LTQ-Orbitrap mass spectrometer. Operating RPLC under a very low flow rate with volatile solvents and MS in the negative mode, we could estimate highly accurate mass values sufficient to predict the nucleotide composition of a ∼21-nucleotide small interfering RNA, detect post-transcriptional modifications in yeast tRNA, and perform collision-induced dissociation/tandem MS-based structural analysis of nucleolytic fragments of RNA at a sub-femtomole level. Importantly, the method allowed the identification and chemical analysis of small RNAs in ribonucleoprotein (RNP) complex, such as the pre-spliceosomal RNP complex, which was pulled down from cultured cells with a tagged protein cofactor as bait. We have recently developed a unique genome-oriented database search engine, Ariadne, which allows tandem MS-based identification of RNAs in biological samples. Thus, the method presented here has broad potential for automated analysis of RNA; it complements conventional molecular biology-based techniques and is particularly suited for simultaneous analysis of the composition, structure, interaction, and dynamics of RNA and protein components in various cellular RNP complexes