**Research Evidence on High-Fat Diet-Induced Prostate Cancer Development and Progression**

### **Shintaro Narita \*, Taketoshi Nara, Hiromi Sato, Atsushi Koizumi, Mingguo Huang, Takamitsu Inoue and Tomonori Habuchi**

Department of Urology, Akita University School of Medicine, Akita 010-8543, Japan; bkspt512@yahoo.co.jp (T.N.); hiromisato2002@yahoo.co.jp (H.S.); koizu3atsu4@yahoo.co.jp (A.K.); huangmg0319@yahoo.co.jp (M.H.); takmitz@gmail.com (T.I.); thabuchi@gmail.com (T.H.) **\***Correspondence:naritashintaro@gmail.com;Tel.:+81-18-884-6154

Received: 22 March 2019; Accepted: 29 April 2019; Published: 30 April 2019

**Abstract:** Although recent evidence has suggested that a high-fat diet (HFD) plays an important role in prostate carcinogenesis, the underlying mechanisms have largely remained unknown. This review thus summarizes previous preclinical studies that have used prostate cancer cells and animal models to assess the impact of dietary fat on prostate cancer development and progression. Large variations in the previous studies were found during the selection of preclinical models and types of dietary intervention. Subcutaneous human prostate cancer cell xenografts, such as LNCaP, LAPC-4, and PC-3 and genetic engineered mouse models, such as TRAMP and Pten knockout, were frequently used. The dietary interventions had not been standardized, and distinct variations in the phenotype were observed in di fferent studies using distinct HFD components. The use of di fferent dietary components in the research models is reported to influence the e ffect of diet-induced metabolic disorders. The proposed underlying mechanisms for HFD-induced prostate cancer were divided into (1) growth factor signaling, (2) lipid metabolism, (3) inflammation, (4) hormonal modulation, and others. A number of preclinical studies proposed that dietary fat and/or obesity enhanced prostate cancer development and progression. However, the relationship still remains controversial, and care should be taken when interpreting the results in a human context. Future studies using more sophisticated preclinical models are imperative in order to explore deeper understanding regarding the impact of dietary fat on the development and progression of prostate cancer.

**Keywords:** animal model; diet; fat; in vitro; in vivo; mouse; prostate cancer
