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Gastric cancer is one of the most lethal human malignancies in the world. Although great efforts are put in developing novel therapeutic targets, the effective targeting drugs are still limited. Recent studies reveal the abnormality of Hippo/YAP axis play critical role in the oncogenic process of gastric cancer. It is of great importance to demonstrate the regulation of Hippo signaling activity and YAP protein turnover in gastric cancer. Besides, the phosphorylation cascade on YAP function, which has been thoroughly investigated, the ubiquitination of YAP is also important in Hippo signaling status. Here, We utilized the DUB (Deubiquitinase) siRNA library to identify critical DUB for Hippo signaling. We discovered OTUB1 as a critical factor to facilitate gastric cancer cell stemness and progression, which deubiquitinated and stabilized YAP protein. The clinical data analysis implicated OTUB1 was higher expressed in gastric cancer, which correlated with YAP activity and poor survival. OUTB1 interacted with YAP protein via its OTU domain (Ovarian tumor domain) and deubiquitinated YAP at several lysine sites (K90, K280, K343, K494 and K497), which subsequently inhibited YAP degradation. Our study revealed a novel deubiquitinase of Hippo/YAP axis and one possible therapeutic target for YAP-driven gastric cancer.

Background Ubiquitous mitochondrial creatine kinase (uMtCK) transfers high-energy phosphates from mitochondrially generated ATP to creatine to generate phosphocreatine. uMtCK overexpression has been reported in several malignant tumors, however, the clinical significance and impact of uMtCK in gastric cancer (GC) has not been comprehensively studied. Methods We first examined uMtCK expression in GC by quantitative real-time PCR and western blot assays. Then the clinicopathological significance of aberrant uMtCK expression was determined by immunohistochemical staining in a GC tissue microarray. Kaplan–Meier analysis was used for survival analysis. The biological functions of uMtCK in GC cells were explored by wound-healing, transwell assays and glucose metabolism assays in vitro as well as a liver metastasis model by spleen injection in nude mice in vivo. Results We verified that the expression of uMtCK was substantially elevated in GC tissues, significantly associating with a poorer prognosis in GC patients, especially for those with advanced stage. In univariate and multivariate analyses, uMtCK expression emerged as an independent prognostic factor for both disease-free survival and overall survival. Functionally, we demonstrated that uMtCK promoted glycolysis in GC cells and facilitated their migration, invasion and liver metastasis in vitro and in vivo. Mechanistically, uMtCK enhanced GC progression in a HK2-dependent glycolysis via acting the JNK-MAPK/JUN signaling pathway. Conclusions uMtCK could serve as a novel independent prognostic biomarker as well as potential therapeutic target for GC patients, particularly for GC patients with an advanced UICC stage and tumor recurrence.

Radical excision by surgery is the main treatment method for gastric cancer and as the surgery develops, the laparoscopic treatment effect on gastric cancer is gradually being verified. The totally laparoscopic gastrectomy (TLG) with natural orifice specimen extraction surgery (NOSES) for gastric cancer has attracted people's attention by avoiding abdominal incision and further reducing surgical injury and provides ideas for the further development of minimally invasive surgical treatment on the basis of laparoscopy. Surgical technique of TLG with natural orifice (vagina) specimen extraction is detailed in the text. We have employed NOSES in 4 cases of TLG in the past year. The visual analogue scale score was low, and all patients had no complications during and after the operation. No recurrence or metastasis was found in the short-term follow-up. TLG with NOSES is feasible and has many advantages such as aesthetics, light post-operative pain.

ERα positive breast cancer accounts for 70% of breast malignancies. Compared with ERα negative types, ERα positive breast cancer could be effective controlled by endocrine therapy. However, more than half of the patients will develop endocrine resistance, making it an important clinical issue for breast cancer therapy. Endocrine resistance might be caused by multiple alternations, including the components of ERα signaling, during tumor progression. Thus, it is urgent and necessary to uncover the molecular mechanisms that controls ERα expression and stability to improve breast cancer therapeutics. In our current study, we identifies that the ubiquitin ligase RNF181 stabilizes ERα and facilitates breast cancer progression. The expression of RNF181 is correlated with ERα level in human breast tumors and relates to poor survival in endocrine-treated patients. RNF181 depletion inhibits breast cancer progression in vivo and in vitro, reduces ERα protein level and its target gene expression, such as PS2 and GREB1. Unbiased RNA sequencing analysis indicates RNF181 is necessary for ERα signature gene expression in whole genomic level. Immuno-precipitation assays indicate that RNF181 associates with ERα and promotes its stability possibly via inducing ERα K63-linked poly-ubiquitination. In conclusion, our data implicate a non-genomic mechanism by RNF181 via stabilizing ERα protein controls ERα target gene expression linked to breast cancer progression.

The ubiquitination process, which involves that binding of an ubiquitin protein to certain substrates, regulates several human biological processes and human cancers. Several studies report that the abnormal expression of quite a few E3 ubiquitin ligases could play critical role in carcinogenic process and cancer progression. In our current study, we identify UHRF1 (Ubiquitin Like with PHD And Ring Finger Domain 1) is an important regulator for breast cancer growth. UHRF1 depletion significantly decreases breast cancer growth in vitro and in vivo. Clinical data analysis reveals that UHRF1 is dramatically elevated in breast cancer, compared to normal breast tissue. UHRF1 correlates with poor survival in Luminal type of breast cancer patients, but not in ER negative groups. The molecular biological studies show that UHRF1 localizes in the nuclear and interact with ERα via its SRA domain, which subsequently inhibits K48-linked ubiquitination of ERα and enhances ERα stability. Our study provides a novel function of UHRF1 in regulation estrogen signaling in breast cancer and a promising target for breast cancer therapeutics.

Background The Hippo pathway functions as a tumor-suppressor pathway in human cancers, while the dys-function of Hippo pathway is frequently observed in malignancies. Although the YAP/TAZ activity is tightly controlled by the phosphorylation cascade of MST-LATS-YAP/TAZ axis, it is still unclear why YAP/TAZ protein is activated in human cancers, even Hippo pathway is still active. Besides phosphorylation, recent studies implicate that several post-translational modifications also play critical roles in modulating TAZ function, including ubiquitination. Methods We work on the ER alpha positive breast cancer cell lines and performed western blots, real-time PCR, immuno-precipitation assay, in vitro ubiquitin assay and xenograft mice studies Results Here, by a DUB (Deubiquitinases) siRNA screening library, we discovered DUB1 as a critical modulator to facilitate gastric cancer stemness and progression, which deubiquitinated and activated TAZ protein. We also identified DUB1 was elevated in gastric cancer, which correlated with TAZ activation and poor survival. DUB1 associated with TAZ protein and deubiquitinated TAZ at several lysine sites, which subsequently stabilized and facilitated TAZ function. Conclusions Our study revealed a novel deubiquitinase of Hippo/TAZ axis and one possible therapeutic target for Hippo-driven gastric cancer.

Background Gastric cancer (GC) is one of the most common malignant tumors of digestive tract origin in China. The proportion of elderly patients with gastric cancer (GC) gradually increases as the population ages. We aimed to develop a prognostic nomogram for prediction of elderly (≥ 75 years old) GC patients in overall survival (OS). Patients and Methods Patients with GC from 2005 to 2014 were selected from the Surveillance, Epidemiology, and End Result (SEER) database and randomly assigned to development and validation sets. The variables for establishing nomogram were confirmed by univariate and multivariate Cox proportional hazard analysis based on the development set. The predictive accuracy and discriminative ability of the model was evaluated using the receiver operating characteristic (ROC) curve, the concordance index (C-index) and calibration curves, while its clinical utility was assessed using decision curve analysis (DCA) and Kaplan-Meier curve. Results A total of 1445 patients were included in this study. The nomogram was developed including histologic grade, AJCC stage T, N, M and surgery according to the univariate and multivariate cox regression analysis, the area under the time-dependent receiver operating characteristic curve (AUC) and Occam’s Law of Razor. The C-index of the nomogram was higher than the TNM system in the training cohort (0.710 vs 0.652, p p