The Hippo Transducer YAP/TAZ as a Biomarker of Therapeutic Response and Prognosis in Trastuzumab-Based Neoadjuvant Therapy Treated HER2-Positive Breast Cancer Patients.

BACKGROUND: We explored the therapeutic and prognostic effect of YAP/TAZ intensityinHER2-positive breast cancer patients. We also investigated the relationship between YAP/TAZ expression and Trastuzumab-resistance. METHODS: We collected clinicopathological information from 397 cases. We evaluated therapeutic and prognostic effect of YAP/TAZ and other variables. We also cultivated Trastuzumab-resistance cell lines and explored relationship between YAP/TAZ and Trastuzumab-resistance. RESULTS: Over-expression of YAP/TAZ was remarkable in Trastuzumab-resistant cells, and so did HER3 and HER2/HER3 heterodimer. Inhibition of YAP/TAZ expression reversed Trastuzumab-resistance.YAP/TAZ deficiency contributed to favorable therapeutic response, and so did hormone receptor insufficiency and chemotherapy dosage inferiority. Deficient YAP/TAZ intensity and abundant hormone receptor intensity contributed to better survival. Over-expression of YAP/TAZ was obvious in recurrent cases in comparison with their matching primary lesions. Prognostic superiority of insufficient YAP/TAZ intensity was more outstanding in hormone receptor negative cases. Over-expression of YAP/TAZ and HER3 was generally synchronous. Absence of HER3 expression in residual lesions might correlate with better breast cancer-free survival. CONCLUSIONS: Over-expression of YAP/TAZ as well as HER-3 and HER2/HER3 heterodimer was synchronously remarkable in Trastuzumab-resistant cell lines. Inhibition of YAP/TAZ expression reversed Trastuzumab resistance. Deficient YAP/TAZ intensity as well as insufficient hormone receptor intensity and high chemotherapy dosage contributed to favorable therapeutic response. Deficient YAP/TAZ intensity and abundant hormone receptor intensity contributed to better survival, and so did absence of HER3expression in residual lesions. Prognostic superiority of YAP/TAZ expression depended on hormone receptor status. Cases with synchronous over-expression of YAP/TAZ and HER3 suffered poor survival, which revealed the potential effect of YAP/TAZ-HER2/HER3 crosstalk in prognosis of HER2-positive patients.

Prognostic Factors for Luminal B-like Breast Cancer.

This study aimed to examine the prognostic factors of luminal B-like breast cancer. Clinical data of 695 luminal B-like breast cancer patients who had been treated in our hospital during the period of past 4.5 years were collected and analyzed. Estrogen receptor (ER), progesterone receptor (PgR), antigen identified by monoclonal antibody Ki-67 (Ki67) were immunohistochemically detected. Different cutoffs of ER, PgR, and Ki67 were evaluated. Pearson χ2 test was performed to compare categorical parameters. Univariate and multivariate models were used to evaluate predictors of disease free survival (DFS). The results showed that patients who were younger, and had larger tumors, and more positive lymph nodes were more likely to receive neo-adjuvent chemotherapy (NAC). Patients with ER-positive tumors having <10% positive cells received more anthracycline- and taxane-based chemotherapy and less endocrine therapy than those with ER-positive tumors having ≥10% positive cells (P=0.004 and P=0.007, respectively); however, patients with ER-positive tumors having <10% positive cells experienced more recurrence (P<0.001). PgR expression levels were not associated with therapeutic schedule and DFS. Patients with tumor tissue Ki67 score ≥30% received more anthracycline- and taxane-based chemotherapy and had worse DFS than those with tumor tissue Ki67 score <30%. Univariate and multivariate analysis showed that clinical T stage, lymph nodes, ER, Ki67, and HER2 status were independent prognostic factors. In conclusion, ER-positive rate <10% and Ki67 score ≥30%, similar to higher clinical T stage, more metastatic lymph nodes, and HER2 positive status, may indicate a worse prognosis for luminal B-like breast cancer patients. Multi-center prospective trials with larger sample sizes are necessary for the continued perfection of our work.

NEK4 kinase regulates EMT to promote lung cancer metastasis.

Epithelial-to-mesenchymal transition (EMT) is a dynamic transitional state from the epithelial to mesenchymal phenotypes. Numerous studies have suggested that EMT and its intermediate states play important roles in tumor invasion and metastasis. To identify novel regulatory molecules of EMT, we screened a siRNA library targeting human 720 kinases in A549 lung adenocarcinoma cells harboring E-cadherin promoter-luciferase reporter vectors. NIMA-related kinase-4 (NEK4) was identified and characterized as a positive regulator of EMT in the screening. Suppression of NEK4 resulted in the inhibition of cell migration and invasion, accompanying with an increased expression of cell adhesion-related proteins such as E-cadherin and ZO1. Furthermore, NEK4 knockdown caused the decreased expression of the transcriptional factor Zeb1 and Smads proteins, which are known to play key roles in EMT regulation. Consistently, overexpression of NEK4 resulted in the decreased expression of E-cadherin and increased expression of Smad3. Using a mouse model with tail vein injection of NEK4 knockdown stable cell line, we found a lower rate of tumor formation and metastasis of the NEK4-knockdown cells in vivo. Thus, this study demonstrates NEK4 as a novel kinase involved in regulation of EMT and suggests that NEK4 may be further explored as a potential therapeutic target for lung cancer metastasis.

Molecular mechanisms and treatment of radiation-induced lung fibrosis.

Radiation-induced lung fibrosis (RILF) is a severe side effect of radiotherapy in lung cancer patients that presents as a progressive pulmonary injury combined with chronic inflammation and exaggerated organ repair. RILF is a major barrier to improving the cure rate and well-being of lung cancer patients because it limits the radiation dose that is required to effectively kill tumor cells and diminishes normal lung function. Although the exact mechanism is unclear, accumulating evidence suggests that various cells, cytokines and regulatory molecules are involved in the tissue reorganization and immune response modulation that occur in RILF. In this review, we will summarize the general symptoms, diagnostics, and current understanding of the cells and molecular factors that are linked to the signaling networks implicated in RILF. Potential approaches for the treatment of RILF will also be discussed. Elucidating the key molecular mediators that initiate and control the extent of RILF in response to therapeutic radiation may reveal additional targets for RILF treatment to significantly improve the efficacy of radiotherapy for lung cancer patients.