Tzu-Ping Lin

REST reduction is essential for hypoxia-induced neuroendocrine differentiation of prostate cancer cells by activating autophagy signaling

Prostate cancer (PCa) with neuroendocrine differentiation (NED) is tightly associated with hormone refractory PCa (HRPC), an aggressive form of cancer that is nearly impossible to treat. Determining the mechanism of the development of NED may yield novel therapeutic strategies for HRPC. Here, we first demonstrate that repressor element-1 silencing transcription factor (REST), a transcriptional repressor of neuronal genes that has been implicated in androgen-deprivation and IL-6 induced NED, is essential for hypoxia-induced NED of PCa cells. Bioinformatics analysis of transcriptome profiles of REST knockdown during hypoxia treatment demonstrated that REST is a master regulator of hypoxia-induced genes. Gene set enrichment analysis (GSEA) of hypoxia and REST knockdown co-upregulated genes revealed their correlation with HRPC. Consistently, gene ontology (GO) analysis showed that REST reduction potential associated with hypoxia-induced tumorigenesis, NE development, and AMPK pathway activation. Emerging reports have revealed that AMPK activation is a potential mechanism for hypoxia-induced autophagy. In line with this, we demonstrate that REST knockdown alone is capable of activating AMPK and autophagy activation is essential for hypoxia-induced NED of PCa cells. Here, making using of in vitro cell-based assay for NED, we reveal a new role for the transcriptional repressor REST in hypoxia-induced NED and characterized a sequential molecular mechanism downstream of REST resulting in AMPK phosphorylation and autophagy activation, which may be a common signaling pathway leading to NED of PCa.

Transrectal ultrasound-guided prostate biopsy in Taiwan: A nationwide database study.

Background For patients with an elevated prostate specific antigen (PSA) level or a suspected lesion detected by digital rectal examination, transrectal ultrasound‐guided (TRUS) prostate biopsy is the standard procedure for prostate cancer diagnoses. In Taiwan, TRUS prostate biopsy has not been well‐studied on a nationwide scale. This article aimed to study TRUS prostate biopsy in Taiwan and its related complications, according to the claims generated through the National Health Insurance (NHI) program. Methods We applied for access to claims from the NHI Research Database of Taiwan of all patients who visited the urology clinic during the period of 2006 to 2010. In the 5‐year urology profile, we obtained all records, which included admission and ambulatory clinical records. The definition of TRUS biopsy included codes for ultrasound‐guided procedure and for prostate puncture; other codes involving complications such as postbiopsy voiding difficulty, significant bleeding, or infection requiring treatment were also included. Risk factors included age, diagnosis of prostate cancer, hospitalization or nonhospitalization, and the Charlson Comorbidity Index (CCI; with a value of 0, 1, 2 or ≥ 3). Descriptive and comparative analyses were also performed. Results In the 5‐year urology profile, 12,968 TRUS biopsies performed of which 6885 were in‐patient procedures and 6083 were ambulatory clinic procedures. After the procedures, 1266 (9.76%) biopsies were associated with voiding difficulty; 148 (1.14%) biopsies, with significant bleeding; and 855 (6.59%) biopsies, with infection that required treatment. The prostate cancer diagnosis rate was 36.02%. The overall biopsy‐related mortality rate within 30 days was 0.25%, and the postbiopsy sepsis‐related mortality rate was 0.13%. Age, diagnosis of cancer, hospitalization, and CCI value ≥ 1 were all significant factors in univariate analysis and multivariate analysis for postbiopsy voiding difficulty and severe infection. A diagnosis of cancer and a CCI value ≥ 2 were significant factors for significant bleeding after biopsy. Patients diagnosed as having prostate cancer had fewer bleeding complications after biopsy. Conclusion The most frequent complication was postbiopsy voiding difficulty, followed by infection that required treatment and significant bleeding. The sepsis‐related mortality rate was 0.13%. Significant risk factors for postbiopsy complications included age, diagnosis of prostate cancer, hospitalization, and the CCI value.

Four-and-a-Half LIM Domains Protein 2 Is a Coactivator of Wnt Signaling in Diabetic Kidney Disease

Diabetic kidney disease (DKD) is a microvascular complication that leads to kidney dysfunction and ESRD, but the underlying mechanisms remain unclear. Podocyte Wnt-pathway activation has been demonstrated to be a trigger mechanism for various proteinuric diseases. Notably, four-and-a-half LIM domains protein 2 (FHL2) is highly expressed in urogenital systems and has been implicated in Wnt/β-catenin signaling. Here, we used in vitro podocyte culture experiments and a streptozotocin-induced DKD model in FHL2 gene-knockout mice to determine the possible role of FHL2 in DKD and to clarify its association with the Wnt pathway. In human and mouse kidney tissues, FHL2 protein was abundantly expressed in podocytes but not in renal tubular cells. Treatment with high glucose or diabetes-related cytokines, including angiotensin II and TGF-β1, activated FHL2 protein and Wnt/β-catenin signaling in cultured podocytes. This activation also upregulated FHL2 expression and promoted FHL2 translocation from cytosol to nucleus. Genetic deletion of the FHL2 gene mitigated the podocyte dedifferentiation caused by activated Wnt/β-catenin signaling under Wnt-On, but not under Wnt-Off, conditions. Diabetic FHL2(+/+) mice developed markedly increased albuminuria and thickening of the glomerular basement membrane compared with nondiabetic FHL2(+/+) mice. However, FHL2 knockout significantly attenuated these DKD-induced changes. Furthermore, kidney samples from patients with diabetes had a higher degree of FHL2 podocyte nuclear translocation, which was positively associated with albuminuria and progressive renal function deterioration. Therefore, we conclude that FHL2 has both structural and functional protein-protein interactions with β-catenin in the podocyte nucleus and that FHL2 protein inhibition can mitigate Wnt/β-catenin-induced podocytopathy.

Primary sweat gland carcinosarcoma of the scrotal skin.

Background:  Carcinosarcoma is a biphasic tumor composed of malignant epithelial and mesenchymal elements. Although the tumors have been reported in different locations, they rarely occur in the skin and have not been reported in the skin of external genitalia.

REST is a crucial regulator for acquiring EMT-like and stemness phenotypes in hormone-refractory prostate cancer

Castration-resistance prostate cancer (CRPC), also known as hormone-refractory prostate cancer (HRPC), requires immediate attention since it is not only resistant to androgen ablation, chemo- and radiotherapy, but also highly metastatic. Increasing evidence suggests that enrichment of neuroendocrine (NE) cells is associated with CRPC. Here, combined RNA-seq and ChIP-seq analysis reveals that REST is involved in epithelial-mesenchymal transition (EMT) and stemness acquisition in NE differentiated prostate cancer (PCa) cells via direct transcriptional repression of Twist1 and CD44. Specifically we show that short-term knockdown of REST induces NE differentiation of LNCaP cells. Long-term REST knockdown enhanced the expression of Twist1 and CD44, cell migration and sphere formation. Overexpression of REST in hormone-refractory CWR22Rv1 PCa cells significantly reduces Twist1 and CD44 expression, cell migration and sphere formation. Collectively, our study uncovers REST in regulating EMT and stemness properties of NE PCa cells and suggests that REST is a potential therapeutic target for CRPC.

MAOA-a novel decision maker of apoptosis and autophagy in hormone refractory neuroendocrine prostate cancer cells

Autophagy and apoptosis are two well-controlled mechanisms regulating cell fate. An understanding of decision-making between these two pathways is in its infancy. Monoamine oxidase A (MAOA) is a mitochondrial enzyme that is well-known in psychiatric research. Emerging reports showed that overexpression MAOA is associated with prostate cancer (PCa). Here, we show that MAOA is involved in mediating neuroendocrine differentiation of PCa cells, a feature associated with hormone-refractory PCa (HRPC), a lethal type of disease. Following recent reports showing that NED of PCa requires down-regulation of repressor element-1 silencing transcription factor (REST) and activation of autophagy; we observe that MAOA is a novel direct target gene of REST. Reactive oxygen species (ROS) produced by overexpressed MAOA plays an essential role in inhibiting apoptosis and activating autophagy in NED PCa cells. MAOA inhibitors significantly reduced NED and autophagy activation of PCa cells. Our results here show MAOA as a new decision-maker for activating autophagy and MAOA inhibitors may be useful as a potential therapy for neuroendocrine tumors.

HOTAIR is a REST-regulated lncRNA that promotes neuroendocrine differentiation in castration resistant prostate cancer

Long non-coding RNAs (lncRNAs) are emerging as novel diagnostic markers of prostate cancer (PCa) and new determinants of castration-resistant PCa (CRPC), an aggressive and metastatic form of PCa. In addition to androgen receptor (AR) signaling, neuroendocrine differentiation (NED) is associated with CRPC. Recent reports demonstrate that the downregulation of repressor element-1 silencing transcription factor (REST) protein is a key step in NED of PCa cells. Here, we report HOTAIR as a novel REST-repressed lncRNA that is upregulated in NED PCa cells and in CRPC. HOTAIR overexpression is sufficient to induce, whereas knockdown of HOTAIR suppressed NED of PCa cells. Gene ontology (GO) analysis of differentially expressed genes under HOTAIR overexpression and in CRPC versus benign prostatic hyperplasia (BPH) suggests that HOTAIR may participate in PCa progression. Taken together, our results provide the first evidence of lncRNA HOTAIR as a driver for NED of PCa cells.

A nationwide population study of trazodone use in urology patients

Background: Erectile dysfunction (ED) has been a prevalent disease worldwide. The mainstay of treatment for ED focused on oral medications such as phosphodiesterase‐5 (PDE‐5) inhibitors or other medical aids with variable acceptance. Trazodone is a second‐generation antidepressant approved by the U.S. Food and Drug Administration in 1981. Some evidence has suggested that trazodone may be helpful in improving ED, especially for problems dealing with male arousal. Although controversial, trazodone can sometimes be used for ED as an off‐label medication for urological patients. By using a nationwide health insurance database, we attempted to estimate and thereafter analyze the existence and extent of off‐label use of trazodone for ED in Taiwan. Methods: The 1/500 randomly sampled outpatient visits dataset and the 1/1 million randomly selected dataset issued in 2000 in the National Health Insurance Research Database were used to estimate the total number of visits and the urological visits involving trazodone prescriptions. The refill rate, patient age at first prescription, and the diagnoses assigned to the prescription visits were also gathered and analyzed. Results: The prescription visits in urological clinics consisted exclusively of male patients (99.0 ± 1.3%, p < 0.001). The use of trazodone was more prevalent and regular among the elderly (p < 0.001), which happens to parallel the trend of incidence rates of ED. Starting in 1998, the prescription rate for trazodone increased rapidly, but then slowed, equalized, and topped out in 2003. One of the reasons for this marked change in prescriptions rates in Taiwan may be the increased awareness of ED as a treatable disease under the promotion and marketing of three PDE‐5 inhibitors. ED‐related diagnoses assigned to the prescription visits accounted for 55% of total visits, whereas anxiety/depression‐associated diagnoses were the bases of less than 13%, and those attributed to insomnia accounted for 2.3% of visits. Conclusion: Despite the fact that trazodone was not officially approved for patients with urological conditions, this medication has been used as an ED treatment in Taiwan at least since 1997; the prescriptions of trazodone were more prevalent among the elderly, and this trend increased, then evened out, and eventually reached its maximum point in 2003, correlating with the introduction of PDE‐5 inhibitors.

Clinical efficacy of transrectal ultrasound-guided prostate biopsy in men younger than 50 years old with an elevated prostate-specific antigen concentration (>4.0 ng/mL)

Background Prostate cancer (PCa) is not commonly found in men younger than 50 years of age. However, serum prostate‐specific antigen (PSA) concentration has been examined more frequently at a younger age in Asia partially due to an increased awareness of prostate cancer. The purpose of our study was to investigate the efficacy and complication of PSA‐triggered transrectal ultrasonography‐guided prostate (TRUSP) biopsies. We retrospectively reviewed TRUSP biopsies in young men with elevated PSA concentration in Taipei Veterans General Hospital. Methods We reviewed the cases of patients younger than 50 years of age with elevated PSA concentration (>4.0 ng/mL), who received 12 cores TRUSP biopsies at TPEVGH from January 2008–December 2013. The age, family history, digital rectal examination (DRE) results, PSA concentration, free/total PSA ratio, total prostate volume, PSA density, lower urinary tract symptoms and complications after the procedure were reviewed. The pathologic findings of TRUSP biopsy and clinical follow‐up were reviewed and analyzed according to the Epstein criteria. Results A total of 77 patients were included and were divided into 2 groups: 1) the younger group consisted of 20 patients <40 years of age; and 2) the elder group had 57 patients who were 40–50 years of age. The overall detection rate of PCa was 11.69% (9/77), and all of the PCa cases were diagnosed in the elder group (group detection rate: 15.8%). There was a significant difference in the severity of lower urinary tract symptoms (LUTS) between these 2 groups. All PCa patients were clinically significant according to the Epstein criteria. Two patients experienced fever (2.60%) after TRUSP biopsy. Conclusion From our patient cohort, it appears that no benefit was apparent for patients younger than 40 years old who received TRUSP biopsy, even with elevated PSA. However, PCa detected in men between 40 and 50 years of age were all clinically significant. Overall, our results supported current major practice guidelines which recommend an initial PSA checkup at 40 years of age.

Cognitive MRI-TRUS fusion-targeted prostate biopsy according to PI-RADS classification in patients with prior negative systematic biopsy results.

Background The purpose of this study was to evaluate the prostate cancer yield rate of targeted transrectal ultrasound (TRUS)‐guided biopsy with cognitive magnetic resonance imaging (MRI) registration without concurrent systematic biopsy in patients with previous negative systematic TRUS‐guided biopsy results and persistently elevated prostate‐specific antigen (PSA) levels. Methods In this prospective study conducted from August 2013 to January 2015, patients with at least one previous negative systematic TRUS‐guided biopsy and persistently high PSA (≥4 ng/mL) levels were referred for multiparametric MRI (mpMRI). Those patients with suspicious findings on mpMRI received a subsequent cognitive MRI‐TRUS fusion biopsy. The cancer‐detection rate, tumor location, and Gleason score were confirmed, and PSA‐related data were compared between cancer‐yield and noncancer‐yield groups. Results In total, 48 patients were included in this study. MRI was designated to be four and five in 17 patients. Fifteen patients received a cognitive fusion‐targeted biopsy, and prostate cancers were detected in 10 patients. The cancer‐detection rate was 20.8% (10/48), and the positive‐predictive value of MRI was 66.7%. No significant differences were observed in the PSA level, PSA velocity, or transitional zone volume between the cancer‐yield and noncancer‐yield groups; however, the corresponding difference in PSA transitional zone density was significant (p = 0.025). Conclusion Cognitive MRI‐TRUS fusion‐targeted biopsy without concurrent systematic biopsy can detect significant prostate cancer in patients with previous negative systematic biopsy results and persistently elevated PSA levels. Noncancer‐yield patients should undergo active surveillance and further follow‐ups.