Salubrinal Exposes Anticancer Properties in Inflammatory Breast Cancer Cells by Manipulating the Endoplasmic Reticulum Stress Pathway.

The endoplasmic reticulum (ER) regulates protein folding, post-translational modifications, lipid synthesis, and calcium signaling to attenuate the accumulation of misfolded proteins causing ER stress and maintains cellular homeostasis. The tumor microenvironment is rich in soluble cytokines, chemokines, growth, and angiogenic factors and can drive the ER's abnormal functioning in healthy cells. Cancer cells adapt well to the tumor microenvironment induced ER stress. We identified that the inflammatory breast cancer (IBC) cells abundantly express osteoprotegerin (OPG) and their tumor microenvironment is rich in OPG protein. OPG also called osteoclast differentiation factor/osteoclastogenesis inhibitory factor (OCIF) is a soluble decoy receptor for receptor activator of nuclear factor-kappa B ligand (RANKL). Employing mass spectrometry analysis, we identified a set of ER chaperones associated with OPG in IBC cell lysates (SUM149PT, SUM1315MO2) compared to healthy human mammary epithelial cells (HMEC). Proximity ligation assay (PLA) and immunoprecipitation assay validated the interaction between OPG and ER chaperone and master regulator of unfolded protein response (UPR) GRP78/BiP (glucose-regulated protein/Binding immunoglobulin protein). We detected remarkably high gene expression of CCAAT enhancer-binding protein homologous protein (CHOP), inositol-requiring enzyme 1 (IRE1α), protein disulfide-isomerase (PDI), PKR-like ER kinase (PERK), activating transcription factor 4 (ATF4), X-box binding protein 1 (XBP-1) and growth arrest and DNA damage-inducible protein (GADD34) in SUM149PT and SUM190PT cells when compared to HMEC. Similarly, tissue sections of human IBC expressed high levels of ER stress proteins. We evaluated cell death and apoptosis upon Salubrinal and phenylbutyrate treatment in healthy and IBC cells by caspase-3 activity and cleaved poly (ADP-ribose) polymerase (PARP) protein assay. IBC (SUM149PT and SUM190PT) cells were chemosensitive to Salubrinal treatment, possibly via inhibition in OPG secretion, upregulating ATF4, and CHOP, thus ultimately driving caspase-3 mediated IBC cell death. Salubrinal treatment upregulated PDI, which connects ER stress to oxidative stress. We observed increased ROS production and reduced cell proliferation of Salubrinal treated IBC cells. Treatment with antioxidants could rescue IBC cells from ROS and aborted cell proliferation. Our findings implicate that manipulating ER stress with Salubrinal may provide a safer and tailored strategy to target the growth of inflammatory and aggressive forms of breast cancer.

alphaB-crystallin is a novel predictor of resistance to neoadjuvant chemotherapy in breast cancer.

AIMS: alphaB-crystallin is an anti-apoptotic protein commonly expressed in poor prognosis basal-like breast tumors, which are largely triple (estrogen receptor (ER), progesterone receptor (PR), and HER2) negative. We examined whether alphaB-crystallin expression in breast cancer was associated with a poor response to neoadjuvant (preoperative) chemotherapy. METHODS: One hundred and twelve breast cancer patients who received neoadjuvant chemotherapy and who had post-chemotherapy tumor specimens available for analysis were included in the study. Forty-nine percent of patients were treated with doxorubicin and cyclophosphamide (AC), 37% received AC in combination with a taxane, and 14% received other regimens. Paired pre- and post-chemotherapy tumor specimens were available for 33 patients. alphaB-crystallin expression was determined by immunohistochemistry in tissue microarrays. RESULTS: Seventeen percent of tumors were alphaB-crystallin positive. alphaB-crystallin expression was identical in 32 of 33 cases for which both pre- and post-chemotherapy tumor tissue was available. alphaB-crystallin expression was associated with ER-negative (P = 0.0024) and triple negative status (P = 0.005). Overall response rates (ORR) defined as > or =50% reduction in tumor size after treatment were 53% (clinical ORR) and 61% (pathological ORR). Although tumor grade, size, ER, PR, HER2 or triple negative status was not associated with response, alphaB-crystallin-positive tumors had poorer overall response rates than alphaB-crystallin-negative tumors (clinical ORR, 21% vs. 59%, respectively, P = 0.0045; pathological ORR, 16% vs. 70%, respectively, P < 0.0001). CONCLUSION: alphaB-crystallin is a novel biomarker expressed predominantly in triple negative breast tumors that identifies a subset of chemotherapy-resistant tumors, which may contribute to their poor prognosis.

Reduction mammaplasty is a functional operation, improving quality of life in symptomatic women: a prospective, single-center breast reduction outcome study.

Breast hypertrophy creates a functional disability, adversely affecting quality of life because of disproportionate upper body weight. No study to date has prospectively shown or statistically proved (using validated questionnaires) the functional benefits of breast reduction surgery. Moreover, no study has quantified the physical findings seen in these patients. A prospective trial was designed to illustrate objectively the functional benefits of breast reduction surgery and answer the question, Does surgically removing breast tissue in symptomatic patients (regardless of amount of tissue removed) improve their physical disabilities related to breast hypertrophy, and in turn, improve their quality of life? Fifty-five consecutive patients with an average age of 38 years (range, 18 to 73 years) undergoing breast reduction surgery by the senior surgeon (L.A.C.) were recruited for this study. The North American Spine Society (NASS) Lumbar Spine Outcome Assessment Instrument was used to assess patients' disability, expectations for treatment, and satisfaction with treatment. The visual analogue scale was used to quantify pain intensity. Muscle strengths of the pectoralis major, pectoralis minor, rhomboid, middle trapezius, and lower trapezius muscles and postural measures were obtained. Information was collected preoperatively and 6 months postoperatively for comparison. The mean cumulative preoperative NASS Lumbar Spine Outcome Assessment Instrument disability score was 1.94 +/- 0.68, and the mean cumulative postoperative disability score was 1.16 +/- 0.35 (p = 0.0001); 96.1 percent of patients met expectations to a certain degree and, of these patients, 96 percent were very satisfied with their surgery. The mean cumulative baseline preoperative visual analogue score for all participants was 6.2 +/- 2.06, and their mean cumulative postoperative score was 0.53 +/- 0.88 (p = 0.0001). There was statistically significant improvement of muscle strength in the rhomboids, middle trapezius, and lower trapezius muscles (p < 0.001). All postural measures showed improvement postoperatively, with head translation and cranial rotation showing statistical improvement (p < 0.05). This single-center, single-surgeon breast reduction outcome study showed that the signs and symptoms of breast hypertrophy are definable in a consistent manner. By standardizing and quantifying preoperative and postoperative evaluations with validated questionnaires, validated pain scoring, and standardized muscle and posture testing, it was shown that breast reduction for symptomatic breast hypertrophy can effect a statistically significant improvement in these objective measures of pain, disability, muscle weakness, and poor posture.