Yes-associated protein expression in paired primary and local recurrent breast cancer and its clinical significance

The molecular crosstalk of the hippo cascade in breast cancer: A potential central susceptibility

The incidence of breast cancer is perpetually growing globally, and it remains a major public health problem and the leading cause of mortality in women. Though the aberrant activities of the Hippo pathway have been reported to be associated with cancer, constructive knowledge of the pathway connecting the various elements of breast cancer remains to be elucidated. The Hippo transducers, yes-associated protein (YAP) and transcriptional co-activator with PDZ binding motif (TAZ), are reported to be either tumor suppressors, oncogenes, or independent prognostic markers in breast cancer. Thus, there is further need for an explicative evaluation of the dilemma with this molecular contribution of Hippo transducers in modulating breast malignancy. In this review, we summarize the intricate crosstalk of the Hippo pathway in different aspects of breast malignancy, including stem-likeness, cellular signaling, metabolic adaptations, tumor microenvironment, and immune responses. The collective data shows that Hippo transducers play an indispensable role in mammary tumor formation, progression, and dissemination. However, the cellular functions of YAP/TAZ in tumorigenesis might be largely dependent on the mechanical and biophysical cues they interact with, as well as on the cell phenotype. This review provides a glimpse into the plausible biological contributions of the cascade to the inward progression of breast carcinoma and suggests potential therapeutic prospects.

RBCK1 is an endogenous inhibitor for triple negative breast cancer via hippo/YAP axis

BACKGROUND

Triple negative breast cancer (TNBC) is one of the most lethal breast cancer subtypes. Due to a lack of effective therapeutic targets, chemotherapy is still the main medical treatment for TNBC patients. Thus, it is important and necessary to find new therapeutic targets for TNBC. Recent genomic studies implicated the Hippo / Yap signal is over activated in TNBC, manifesting it plays a key role in TNBC carcinogenesis and cancer progression. RBCK1 was firstly identified as an important component for linear ubiquitin assembly complex (LUBAC) and facilitates NFKB signaling in immune response. Further studies showed RBCK1 also facilitated luminal type breast cancer growth and endocrine resistance via trans-activation estrogen receptor alpha.

METHODS

RBCK1 and YAP protein expression levels were measured by western blotting, while the mRNA levels of YAP target genes were measured by RT-PCR. RNA sequencing data were analyzed by Ingenuity Pathway Analysis. Identification of Hippo signaling activity was accomplished with luciferase assays, RT-PCR and western blotting. Protein stability assays and ubiquitin assays were used to detect YAP protein degradation. Ubiquitin-based immunoprecipitation assays were used to detect the specific ubiquitination modification on the YAP protein.

RESULTS

In our current study, our data revealed an opposite function for RBCK1 in TNBC progression. RBCK1 over-expression inhibited TNBC cell progression in vitro and in vivo, while RBCK1 depletion promoted TNBC cell invasion. The whole genomic expression profiling showed that RBCK1 depletion activated Hippo/YAP axis. RBCK1 depletion increased YAP protein level and Hippo target gene expression in TNBC. The molecular biology studies confirmed that RBCK1 could bind to YAP protein and enhance the stability of YAP protein by promoting YAP K48-linked poly-ubiquitination at several YAP lysine sites (K76, K204 and K321).

CONCLUSION

Our study revealed the multi-faced RBCK1 function in different subtypes of breast cancer patients and a promising therapeutic target for TNBC treatment. Video abstract.

Hippo-TAZ signaling is the master regulator of the onset of triple-negative basal-like breast cancers

Breast cancer is the most frequent malignancy in women worldwide. Basal-like breast cancer (BLBC) is the most aggressive form of this disease, and patients have a poor prognosis. Here, we present data suggesting that the Hippo-transcriptional coactivator with PDZ-binding motif (TAZ) pathway is a key driver of BLBC onset and progression. Deletion of Mob1a/b in mouse mammary luminal epithelium induced rapid and highly reproducible mammary tumorigenesis that was dependent on TAZ but not yes-associated protein 1 (YAP1). In situ early-stage BLBC-like malignancies developed in mutant animals by 2 wk of age, and invasive BLBC appeared by 4 wk. In a human estrogen receptor⁺ luminal breast cancer cell line, TAZ hyperactivation skewed the features of these luminal cells to the basal phenotype, consistent with the aberrant TAZ activation frequently observed in human precancerous BLBC lesions. TP53 mutation is rare in human precancerous BLBC but frequent in invasive BLBC. Addition of Trp53 deficiency to our Mob1a/b-deficient mouse model enhanced tumor grade and accelerated cancer progression. Our work justifies targeting the Hippo-TAZ pathway as a therapy for human BLBC, and our mouse model represents a powerful tool for evaluating candidate agents.

Prognostic Roles of Neutrophil-to-Lymphocyte Ratio and Stromal Tumor-Infiltrating Lymphocytes and Their Relationship in Locally Advanced Triple-Negative Breast Cancer Treated with Neoadjuvant Chemotherapy

Introduction

The neutrophil-to-lymphocyte ratio (NLR) and stromal tumor-infiltrating lymphocytes (sTILs) are associated with immunogenicity and prognosis of patients with triple-negative breast cancer (TNBC).

Objective

To investigated the prognostic roles of NLR and sTILs and their rela-tionship of TNBC patients treated with neoadjuvant chemotherapy (NAC).

Methods

The clinical data of 170 patients with locally advanced TNBC who received NAC from January 2010 to December 2014 were collected. The difference among variables was calculated by χ² test. The association between essential clinicopathological characteristics, pathological complete response (pCR), NLR, and sTILs with disease-free survival (DFS) was analyzed. Kaplan-Meier and Cox analysis were performed to address the effects of clinical parameters on prognosis.

Results

There was a trend that TNBC patients with lower baseline NLR (NLR1) or higher sTILs scoring would obtain a better pCR rate. NLR1 and sTILs were not associated (p > 0.05). Patients with low NLR1 or high sTILs scoring had a significantly improved DFS compared to those with high NLR1 or low sTILs scoring (p = 0.002 and p = 0.001, respectively). The increased lymphocyte count in peripheral blood after NAC was associated with the improved DFS outcome in both high and low NLR1 groups. Cox analysis revealed that NLR1 and sTILs were independent prognostic predictors of DFS outcome (p < 0.001).

Conclusion

Low NLR1 and high sTILs were associated with better DFS outcome in locally advanced TNBC patients treated with NAC. Further studies are needed to explore the connection between systemic and local inflammatory/immune markers.

Quilting suture is better than conventional suture with drain in preventing seroma formation at pectoral area after mastectomy

BACKGROUND

The aim of this study was to compare quilting suture with conventional suture on the formation of seroma at pectoral area after mastectomy (ME) with sentinel lymph nodes biopsy (SLN) or axillary lymph nodes dissection (ALND) for breast cancer.

METHODS

Two hundred thirty-five consecutive breast cancer patients were retrospectively analyzed. The primary outcome was the incidence of Grade 2 or Grade 3 seroma at anterior pectoral area within 1 month postoperatively. We categorized seroma into early or late seroma according to the drainage removal time. Cox regression was used for analysis.

RESULTS

The incidence of Grade 2 and 3 seroma was significantly higher in the conventional suture group compared with that in the quilting suture group (19.3% vs. 9.5%, p = 0.032), which was attributed to the late seroma in Grade 2 and 3. Quilting suture was associated with longer time for fixing flaps compared with that of conventional suture (504.7 s vs. 109.1 s, p < 0.001), but with less volume of drainage. Old age, high body mass index and conventional suture were independently risk factors for Grade 2 and 3 seroma.

CONCLUSIONS

Quilting suture decreased the incidence of Grade 2 and 3 seroma at pectoral area within 1 month after mastectomy, especially the late seroma in Grade 2 and 3.

Roles of neutrophil/lymphocyte ratio in prognosis and in differentiation of potential beneficiaries in HER2-positive breast cancer with trastuzumab therapy

Background

The relationship of neutrophil/lymphocyte ratio (NLR) to prognosis of HER2-positive breast cancer (BC) is not well studied. We aimed to assess the prognostic role of NLR in HER2-positive BC patients treated with or without trastuzumab.

Methods

The clinical data of 843 HER2-positive BC patients from July 2013 to July 2018 were collected. The difference among variables was calculated by chi-square test. The associations between clinicopathological factors, NLR and disease-free survival (DFS) were analyzed by univariate and multivariate analyses.

Results

Patients were divided into three groups. In group 1 containing 255 patients without trastuzumab treatment, pretreatment NLR showed no predictive value. Patients with trastuzumab treatment were divided into two groups on equal, according to pretreatment NLR values, low NLR (group 2) and high NLR (group 3). Patients in group 2 showed significantly higher 3-year DFS rate than patients in group 1 and group 3 (95.3% vs. 91.6% vs. 90.5%, respectively, P = 0.011); patients in the group 1 and group 3 had a similar 3-year DFS outcome. Multivariate analysis showed high pretreatment NLR was significantly associated with shorter DFS (HR = 2.917, 95% CI = 1.055–8.062, P = 0.039) in HER2-positive BC patients treated with trastuzumab.

Conclusions

Among HER2-positive trastuzumab-treated BC patients, low pretreatment NLR value was associated with better DFS, and it might help to differentiate potential beneficiaries of trastuzumab treatment.

Platelet/Lymphocyte Ratio Is Superior to Neutrophil/Lymphocyte Ratio as a Predictor of Chemotherapy Response and Disease-free Survival in Luminal B-like (HER2-) Breast Cancer

BACKGROUND

The neutrophil/lymphocyte ratio (NLR) and platelet/lymphocyte ratio (PLR) have been associated with the prognosis in breast cancer (BC). The relationship of the NLR and PLR with chemotherapy sensitivity and prognosis in luminal B-like (human epidermal growth factor receptor 2-negative [HER2^-]) BC are not well studied.

PATIENTS AND METHODS

The clinical data from 980 patients with luminal B-like (HER2^-) BC from June 2012 to June 2016 were collected. The differences among the variables were calculated using the χ² test. The associations among the clinicopathologic factors, pretreatment NLR, pretreatment PLR, and disease-free survival (DFS) were analyzed using Kaplan-Meier curves and Cox analyses.

RESULTS

The median follow-up was 37 months (range, 5-77 months). For the 480 patients who had received neoadjuvant chemotherapy, low pretreatment PLR values were associated with higher pathologic complete response (pCR) rates compared with the high PLR group (15.8% for low vs. 9.2% for high PLR group; P = .027). Multivariate analyses showed that larger tumors, a greater number of lymph nodes involved, a high Ki-67 score, and a high PLR were independent prognostic factors of worse outcomes for the patients with luminal B-like (HER2^-) BC. The risk of metastasis and/or recurrence was greater for the high PLR group than for the low PLR group (hazard ratio, 1.576; 95% confidence interval, 1.039-2.390; P = .032). The pretreatment NLR showed no such associations among this cohort of patients.

CONCLUSIONS

The results of the present study have shown that the pretreatment PLR is superior to the NLR as a predictor of pCR and DFS outcomes in patients with luminal B-like (HER2^-) BC. A low pretreatment PLR was associated with higher pCR rates after neoadjuvant chemotherapy and was an independent predictive factor for better DFS outcomes among patients with luminal B-like (HER2^-) BC.

Loss of ANCO1 repression at AIB1/YAP targets drives breast cancer progression

Transcription factors critical for the transition of normal breast epithelium to ductal carcinoma in situ (DCIS) and invasive breast cancer are not clearly defined. Here, we report that the expression of a subset of YAP-activated and YAP-repressed genes in normal mammary and early-stage breast cancer cells is dependent on the nuclear co-activator AIB1. Gene expression, sequential ChIP, and ChIP-seq analyses show that AIB1 and YAP converge upon TEAD for transcriptional activation and repression. We find that AIB1-YAP repression of genes at the 1q21.3 locus is mediated by AIB1-dependent recruitment of ANCO1, a tumor suppressor whose expression is progressively lost during breast cancer progression. Reducing ANCO1 reverts AIB1-YAP-dependent repression, increases cell size, and enhances YAP-driven aberrant 3D growth. Loss of endogenous ANCO1 occurs during DCIS xenograft progression, a pattern associated with poor prognosis in human breast cancer. We conclude that increased expression of AIB1-YAP co-activated targets coupled with a loss of normal ANCO1 repression is critical to patterns of gene expression that mediate malignant progression of early-stage breast cancer.

The prognostic value of YAP1 on clinical outcomes in human cancers

Background: As an important downstream factor in the Hippo pathway, yes-associated protein 1(YAP1) has been detected to be elevated in various cancers and demonstrated to play a role in tumor development. Therefore, we evaluated by a meta-analysis the prognostic value of YAP1 in cancer patients.

Results: Sixty-eight studies with 8631 patients were identified. The results indicated that YAP1 overexpression predicted unfavorable patient prognosis in studies with overall survival (OS) (HR=1.76, 95%CI: 1.50-2.06, p<0.001) and disease-free survival (DFS) (HR=1.39, 95%CI: 1.22-1.59, p<0.001), as well as in studies with recurrence-free survival (RFS) (HR=2.38, 95%CI: 1.73-3.27, p<0.001), and disease-specific survival (DSS) (HR=2.04, 95%CI: 1.55-2.70, p<0.001). Meanwhile, YAP1 overexpression was also observed to be significantly associated with worse OS in GEPIA (HR=1.2, p<0.001).

Conclusions: Overexpression of YAP1 showed great association with poorer prognosis in patients with various cancers, particularly liver cancer. Therefore, YAP1 might be an important prognostic marker and a novel target of cancer therapy.

Methods: We searched for potential publications in several online databases and retrieved relevant data. Overall and subgroup analyses were performed. Begg’s and Egger’s tests were used to assess publication bias. Online dataset GEPIA was used to generate the survival curves and verify the prognostic role of YAP1 in patients with tumors.