Prostate Basal Cells Research Articles

PBX3 is a putative biomarker of aggressive prostate cancer.

There is a great need to identify new and better prognostic and predictive biomarkers to stratify prostate cancer patients for optimal treatment. The aims of this study were to characterize the expression profile of pre-B cell leukemia homeobox (PBX) transcription factors in prostate cancer with an emphasis on investigating whether PBX3 harbours any prognostic value. The expression profile of PBX3 and PBX1 in prostate tissue was determined by immunohistochemical and immunoblot analysis. Furthermore, the expression of PBX3 transcript variants was analyzed by RT-PCR, NanoString Technologies®, and by analyzing RNA sequence data. The potential of PBX3 to predict prognosis, either at mRNA or protein level, was studied in four independent cohorts. PBX3 was mainly expressed in the nucleus of normal prostate basal cells, while it showed cytosolic expression in prostatic intraepithelial neoplasia and cancer cells. We detected four PBX3 transcript variants in prostate tissue. Competing risk regression analysis revealed that high PBX3 expression was associated with slower progression to castration resistant prostate cancer (sub-hazard ratio (SHR) 0.18, 95% CI: 0.081-0.42, p values < 0.001). PBX3 expression had a high predictive accuracy (area under the curve (AUC) = 0.82) when combined with Gleason score and age. Patients undergoing radical prostatectomy, with high levels of PBX3 mRNA, had improved prostate cancer specific survival compared to patients expressing low levels (SHR 0.21, 95% CI: 0.46-0.93, p values < 0.001, and AUC = 0.75). Our findings strongly indicate that PBX3 has potential as a biomarker, both as part of a larger gene panel and as an immunohistochemical marker, for aggressive prostate cancer.

Transcriptome profiling links the intrinsic properties of human prostate basal cells to prostate cancer aggressiveness

ABSTRACTGenome-wide transcriptome analysis of human benign prostatic basal and luminal epithelial populations reveals the unexpected findings that basal cells preferentially express gene categories associated with stem cells, neurogenesis, and rRNA biogenesis. Importantly, the basal cell gene expression profile is enriched in clinically advanced, anaplastic, castration-resistant, and metastatic prostate cancers.

High fat diet promotes prostatic basal-to-luminal differentiation and accelerates initiation of prostate epithelial hyperplasia originated from basal cells

Recent lineage tracing studies showed that the prostate basal and luminal cells in adult mice are two independent lineages under the physiological condition, but basal cells are capable of generating luminal progenies during bacterial infection-induced prostatitis. Because acute bacterial infection in human prostate tissues is relatively rare, the disease relevance of the bacterial infection-induced basal-to-luminal differentiation is uncertain. Herein we employ a high fat diet-induced sterile prostate inflammation model to determine whether basal-to-luminal differentiation can be induced by inflammation irrespective of the underlying etiologies. A K14-CreER model and a fluorescent report line are utilized to specifically label basal cells with the green fluorescent protein. We show that high fat diet promotes immune cell infiltration into the prostate tissues and basal-to-luminal differentiation. Increased cell proliferation accompanies basal-to-luminal differentiation, suggesting a concurrent regulation of basal cell proliferation and differentiation. This study demonstrates that basal-to-luminal differentiation can be induced by different types of prostate inflammation evolved with distinct etiologies. Finally, high fat diet also accelerates initiation and progression of prostatic intraepithelial neoplasia that are originated from basal cells with loss-of-function of the tumor suppressor Pten. Because prostate cancer originated from basal cells tends to be invasive, our study also provides an alternative explanation for the association between obesity and aggressive prostate cancer.

Prostate epithelial cell of origin determines cancer differentiation state in an organoid transformation assay

The cell of origin for prostate cancer remains a subject of debate. Genetically engineered mouse models have demonstrated that both basal and luminal cells can serve as cells of origin for prostate cancer. Using a human prostate regeneration and transformation assay, our group previously demonstrated that basal cells can serve as efficient targets for transformation. Recently, a subpopulation of multipotent human luminal cells defined by CD26 expression that retains progenitor activity in a defined organoid culture was identified. We transduced primary human prostate basal and luminal cells with lentiviruses expressing c-Myc and activated AKT1 (myristoylated AKT1 or myrAKT1) to mimic theMYCamplification andPTENloss commonly detected in human prostate cancer. These cells were propagated in organoid culture before being transplanted into immunodeficient mice. We found that c-Myc/myrAKT1-transduced luminal xenografts exhibited histological features of well-differentiated acinar adenocarcinoma, with strong androgen receptor (AR) and prostate-specific antigen (PSA) expression. In contrast, c-Myc/myrAKT1-transduced basal xenografts were histologically more aggressive, with a loss of acinar structures and low/absent AR and PSA expression. Our findings imply that distinct subtypes of prostate cancer may arise from luminal and basal epithelial cell types subjected to the same oncogenic insults. This study provides a platform for the functional evaluation of oncogenes in basal and luminal epithelial populations of the human prostate. Tumors derived in this fashion with defined genetics can be used in the preclinical development of targeted therapeutics.

Prostate cancer: 'Stem-like' prostate basal cells.

Prostate cancer: 'Stem-like' prostate basal cells.

CD133 does not enrich for the stem cell activity in vivo in adult mouse prostates

CD133 is widely used as a marker for stem/progenitor cells in many organ systems. Previous studies using in vitro stem cell assays have suggested that the CD133-expressing prostate basal cells may serve as the putative prostate stem cells. However, the precise localization of the CD133-expressing cells and their contributions to adult murine prostate homeostasis in vivo remain undetermined. We show that loss of function of CD133 does not impair murine prostate morphogenesis, homeostasis and regeneration, implying a dispensable role for CD133 in prostate stem cell function. Using a CD133-CreERT2 model in conjunction with a fluorescent report line, we show that CD133 is not only expressed in a fraction of prostate basal cells, but also in some luminal cells and stromal cells. CD133+ basal cells possess higher in vitro sphere-forming activities than CD133− basal cells. However, the in vivo lineage tracing study reveals that the two cell populations possess the same regenerative capacity and contribute equally to the maintenance of the basal cell lineage. Similarly, CD133+ and CD133− luminal cells are functionally equivalent in maintaining the luminal cell lineage. Collectively, our study demonstrates that CD133 does not enrich for the stem cell activity in vivo in adult murine prostate. This study does not contradict previous reports showing CD133+ cells as prostate stem cells in vitro. Instead, it highlights a substantial impact of biological contexts on cellular behaviors.

147 The C-Myc and TNFα/NF-kB pathways are critically involved in the regulatory network between the undifferentiated prostate basal stem cell state and the more differentiated luminal prostate epithelial cells

147 The C-Myc and TNFα/NF-kB pathways are critically involved in the regulatory network between the undifferentiated prostate basal stem cell state and the more differentiated luminal prostate epithelial cells

Stem cell and neurogenic gene-expression profiles link prostate basal cells to aggressive prostate cancer

The prostate gland mainly contains basal and luminal cells constructed as a pseudostratified epithelium. Annotation of prostate epithelial transcriptomes provides a foundation for discoveries that can impact disease understanding and treatment. Here we describe a genome-wide transcriptome analysis of human benign prostatic basal and luminal epithelial populations using deep RNA sequencing. Through molecular and biological characterizations, we show that the differential gene-expression profiles account for their distinct functional properties. Strikingly, basal cells preferentially express gene categories associated with stem cells, neurogenesis and ribosomal RNA (rRNA) biogenesis. Consistent with this profile, basal cells functionally exhibit intrinsic stem-like and neurogenic properties with enhanced rRNA transcription activity. Of clinical relevance, the basal cell gene-expression profile is enriched in advanced, anaplastic, castration-resistant and metastatic prostate cancers. Therefore, we link the cell-type-specific gene signatures to aggressive subtypes of prostate cancer and identify gene signatures associated with adverse clinical features.

Protein profile of basal prostate epithelial progenitor cells--stage-specific embryonal antigen 4 expressing cells have enhanced regenerative potential in vivo.

The long‐term propagation of basal prostate progenitor cells ex vivo has been very difficult in the past. The development of novel methods to expand prostate progenitor cells in vitro allows determining their cell surface phenotype in greater detail. Mouse (Lin−Sca‐1+ CD49f+ Trop2high‐phenotype) and human (Lin− CD49f+ TROP2high) basal prostate progenitor cells were expanded in vitro. Human and mouse cells were screened using 242 anti‐human or 176 antimouse monoclonal antibodies recognizing the cell surface protein profile. Quantitative expression was evaluated at the single‐cell level using flow cytometry. Differentially expressed cell surface proteins were evaluated in conjunction with the known CD49f+/TROP2high phenotype of basal prostate progenitor cells and characterized by in vivo sandwich‐transplantation experiments using nude mice. The phenotype of basal prostate progenitor cells was determined as CD9+/CD24+/CD29+/CD44+/CD47+/CD49f+/CD104+/CD147+/CD326+/Trop2high of mouse as well as human origin. Our analysis revealed several proteins, such as CD13, Syndecan‐1 and stage‐specific embryonal antigens (SSEAs), as being differentially expressed on murine and human CD49f+ TROP2+ basal prostate progenitor cells. Transplantation experiments suggest that CD49f+ TROP2high SSEA‐4high human prostate basal progenitor cells to be more potent to regenerate prostate tubules in vivo as compared with CD49f+ TROP2high or CD49f+ TROP2high SSEA‐4low cells. Determination of the cell surface protein profile of functionally defined murine and human basal prostate progenitor cells reveals differentially expressed proteins that may change the potency and regenerative function of epithelial progenitor cells within the prostate. SSEA‐4 is a candidate cell surface marker that putatively enables a more accurate identification of the basal PESC lineage.

Loss of ATF3 promotes hormone-induced prostate carcinogenesis and the emergence of CK5+CK8+ epithelial cells

Steroid sex hormones can induce prostate carcinogenesis, and are thought to contribute to the development of prostate cancer during aging. However, the mechanism for hormone-induced prostate carcinogenesis remains elusive. Here we report that activating transcription factor 3 (ATF3) – a broad stress sensor – suppressed hormone-induced prostate carcinogenesis in mice. While implantation of testosterone and estradiol (T+E2) pellets for 2 months in wild-type mice rarely induced prostatic intraepithelial neoplasia (PIN) in dorsal prostates (1 out of 8 mice), loss of ATF3 led to the appearance of not only PIN but also invasive lesions in almost all examined animals. The enhanced carcinogenic effects of hormones on ATF3-deficient prostates did not appear to be caused by a change in estrogen signaling, but were more likely a consequence of elevated androgen signaling that stimulated differentiation of prostatic basal cells into transformation-preferable luminal cells. Indeed, we found that hormone-induced lesions in ATF3-knockout mice often contained cells with both basal and luminal characteristics, such as p63+ cells (a basal cell marker) showing luminal-like morphology, or cells double-stained with basal (CK5+) and luminal (CK8+) markers. Consistent with these findings, low ATF3 expression was found to be a poor prognostic marker for prostate cancer in a cohort of 245 patients. Our results thus support that ATF3 is a tumor suppressor in prostate cancer.

A basal stem cell signature identifies aggressive prostate cancer phenotypes

Evidence from numerous cancers suggests that increased aggressiveness is accompanied by up-regulation of signaling pathways and acquisition of properties common to stem cells. It is unclear if different subtypes of late-stage cancer vary in stemness properties and whether or not these subtypes are transcriptionally similar to normal tissue stem cells. We report a gene signature specific for human prostate basal cells that is differentially enriched in various phenotypes of late-stage metastatic prostate cancer. We FACS-purified and transcriptionally profiled basal and luminal epithelial populations from the benign and cancerous regions of primary human prostates. High-throughput RNA sequencing showed the basal population to be defined by genes associated with stem cell signaling programs and invasiveness. Application of a 91-gene basal signature to gene expression datasets from patients with organ-confined or hormone-refractory metastatic prostate cancer revealed that metastatic small cell neuroendocrine carcinoma was molecularly more stem-like than either metastatic adenocarcinoma or organ-confined adenocarcinoma. Bioinformatic analysis of the basal cell and two human small cell gene signatures identified a set of E2F target genes common between prostate small cell neuroendocrine carcinoma and primary prostate basal cells. Taken together, our data suggest that aggressive prostate cancer shares a conserved transcriptional program with normal adult prostate basal stem cells.

Abstract A28: N-Myc drives small cell neuroendocrine cancer initiated from human prostate basal cells

Abstract Human small cell prostate carcinoma (SCPC) represents up to 25% of lethal castration-resistant prostate cancer. Molecular characterization of a panel of SCPCs recently identified frequent genomic amplification of both MYCN and AURKA. The oncogenic function of N-Myc has been characterized in many cancer types but its role in the initiation of human SCPC has not been defined. To investigate the function of N-Myc in human prostate transformation, we utilized a tissue regeneration model of human prostate cancer. Human prostate basal epithelial cells were isolated from benign primary prostate tissue from four independent human donors, infected with lentiviruses expressing the oncogenes N-Myc and activated (myristoylated) AKT1, mixed with mouse urogenital sinus mesenchyme, and grafted subcutaneously in immunodeficient NOD-SCID-IL2Rγnull mice. Palpable tumors were appreciated within 2-3 months and histological evaluation revealed regions of mixed high-grade adenocarcinoma and small cell carcinoma. The small cell carcinoma histology showed typical findings of high nuclear-to-cytoplasmic ratio, nuclear molding, stippled chromatin, and frequent mitotic and apoptotic features. Immunohistochemical analysis demonstrated low to absent androgen receptor (AR) staining in both the adenocarcinoma and small cell carcinoma. Further, we found heterogeneous staining for neuroendocrine markers including neural cell adhesion molecule 1, chromogranin A, synaptophysin, thyroid transcription factor 1, and forkhead box A2 in the regions of small cell carcinoma in support of the histological diagnosis. To assess the androgen dependence of tumor growth, regenerated N-Myc and activated AKT1 tumors derived from the lentiviral infection of primary human prostate basal cells were passaged in either intact or castrate immunodeficient mice. Tumors were propagated both in the presence and absence of androgens and showed a small but progressive enrichment of the small cell carcinoma over the adenocarcinoma with successive passage in castrate hosts. Molecular profiling by RNA-Seq of three regenerated N-Myc and activated AKT1 tumors showed a significant resemblance to a subset of human SCPC clinical specimens. Further, the adenocarcinoma and small cell carcinoma components of each tumor were remarkably similar at the transcriptional level despite their differences in histological appearance. In conclusion, we have established a novel model of human small cell prostate cancer arising from benign human prostate basal cells. Overexpression of N-Myc and activated AKT1 in basal cells produces tumors that recapitulate the histology, immunophenotype, and transcriptional profile of human SCPC. These findings support a direct role for N-Myc in the neuroendocrine transformation of basal cells in the human prostate. Further studies are ongoing to elucidate the mechanisms by which N-Myc induces a neuroendocrine differentiation program in prostate cancer. Citation Format: John K. Lee, Bryan A. Smith, John W. Phillips, Jungwook Park, Tanya I. Stoyanova, Robert Baertsch, Artem Sokolov, Colleen Mathis, Donghui Cheng, Joshua M. Stuart, Jiaoti Huang, Owen N. Witte. N-Myc drives small cell neuroendocrine cancer initiated from human prostate basal cells. [abstract]. In: Proceedings of the AACR Special Conference on Myc: From Biology to Therapy; Jan 7-10, 2015; La Jolla, CA. Philadelphia (PA): AACR; Mol Cancer Res 2015;13(10 Suppl):Abstract nr A28.

Abstract B18: Myc governs a prostate epithelial differentiation program involving chromatin remodeling protein ING4 and Notch3: Disruption of which is necessary for human prostate cancer development

Abstract Myc is overexpressed in the majority of human prostate cancers and is a known determinant of cell fate, yet the cell of origin from which prostate cancers arise is controversial. Furthermore, the mechanisms by which oncogenes such as Myc disrupt prostate epithelial cell fate are poorly understood. Using a novel human in vitro differentiation model in which prostate basal epithelial cells are induced to differentiate into lumenal cells, we previously demonstrated that Myc-driven prostate cancer develops in an intermediate progenitor cell population whose full differentiation is derailed upon oncogenic transformation (Berger et al, Cancer Res 74:3357-68, 2014). In basal prostate epithelial cells, Myc is required for transient expression of the chromatin-binding protein ING4, which is required for lumenal cell differentiation. In human tissues, ING4 expression is lost in &amp;gt;60% of primary prostate tumors. Loss of ING4 prevented differentiation and was necessary for Myc-dependent tumorigenesis in vivo. ING4 loss generated Myc-dependent tumor cells co-expressing basal and lumenal markers, indicating Myc-dependent oncogenesis disrupted an intermediate step in the prostate epithelial differentiation program. Our objective for this study was to further elucidate the mechanisms by which Myc controls prostate epithelial cell fate. Myc is a known downstream target of Notch1, and several studies suggest Notch signaling is aberrant in prostate cancer; although the mechanistic details are vague. We found that Notch3 is required for lumenal cell differentiation and hypothesized that Notch3 expression is directly controlled by Myc. Inhibition of total Notch signaling with a γ-secretase inhibitor (RO4929097) prevented differentiation. Total Notch1 mRNA and protein levels change very little during differentiation; whereas both Notch3 mRNA and protein increase dramatically. Knock-down of Notch3 by shRNA blocked differentiation, while over expression of active Notch3 (NCID3) induced spontaneous differentiation. Less than 15% of the increase in Notch3 mRNA was attributable to increased mRNA stability, and required new protein synthesis. Temporally, Myc mRNA and protein levels increase prior to Notch3. Blocking Myc expression prevented Notch3 induction. The 2kb proximal promoter region of Notch3 lacked the elements that promote Notch3 induction. We identified a Notch3 enhancer element with Myc binding motifs that support differentiation-induced luciferase reporter activity. We further determined that p38α-MAPK is required for Myc and Notch3 induction. We are currently determining how Myc-dependent regulation of Notch3 influences Myc-dependent regulation of ING4. Thus, our studies demonstrate that at least 2 targets of Myc, ING4 and Notch3, control prostate epithelial cell fate, and that disruption of at least one of them is required for Myc-driven human prostate cancer development. In depth understanding of Myc-driven differentiation pathways will provide new insights into how oncogenic transformation by Myc in intermediate progenitor prostate epithelial cells gives rise to prostate cancer. Funding was provided by the Association for International Cancer Research, NIH/NCI CA154835, Department of Defense W81XWH-14-10479, and the Van Andel Research Institute. Citation Format: Sander B. Frank, Penny L. Berger, Cindy K. Miranti. Myc governs a prostate epithelial differentiation program involving chromatin remodeling protein ING4 and Notch3: Disruption of which is necessary for human prostate cancer development. [abstract]. In: Proceedings of the AACR Special Conference on Myc: From Biology to Therapy; Jan 7-10, 2015; La Jolla, CA. Philadelphia (PA): AACR; Mol Cancer Res 2015;13(10 Suppl):Abstract nr B18.

Deep RNA-Seq analysis reveals unexpected features of human prostate basal epithelial cells

Abstract Prostate cancer is the second leading cause of cancer-related deaths among American men [ 1 ]. The prostate gland mainly contains basal and luminal cells, which are constructed as a pseudostratified epithelium. Annotation of prostate epithelial transcriptomes provides a foundation for discoveries that can impact disease understanding and treatment. Here, for the first time, we describe a whole-genome transcriptome analysis of human benign prostatic basal and luminal populations by using deep RNA sequencing (GSE67070) [2]. Combined with comprehensive molecular and biological characterizations, we show that the differential gene expression profiles account for their distinct functional phenotypes. Strikingly, in contrast to luminal cells, basal cells preferentially express gene categories associated with stem cells, neural and neuronal development, and RNA processing. Of clinical relevance, the treatment failed castration-resistant and anaplastic prostate cancers molecularly resemble a basal-like phenotype. We also identified genes associated with patient clinical outcome. Therefore, we provide a gene expression resource for understanding human prostate epithelial lineages, and link the cell-type specific gene signatures to subtypes of prostate cancer development.

A subset of prostatic basal cell carcinomas harbor the MYB rearrangement of adenoid cystic carcinoma.

Adenoid cystic carcinoma (ACC) is a basaloid tumor consisting of myoepithelial and ductal cells typically arranged in a cribriform pattern. Adenoid cystic carcinoma is generally regarded as a form of salivary gland carcinoma, but it can arise from sites unassociated with salivary tissue. A rare form of prostate carcinoma exhibits ACC-like features; it is no longer regarded as a true ACC but rather as prostatic basal cell carcinoma (PBCC) and within the spectrum of basaloid prostatic proliferations. True ACCs often harbor MYB translocations resulting in the MYB-NFIB fusion protein. MYB analysis could clarify the true nature of prostatic carcinomas that exhibit ACC features and thus help refine the classification of prostatic basaloid proliferations. Twelve PBCCs were identified from the pathology consultation files of Johns Hopkins Hospital. The histopathologic features were reviewed, and break-apart fluorescence in situ hybridization for MYB was performed. All 12 cases exhibited prominent basaloid histology. Four were purely solid, 7 exhibited a cribriform pattern reminiscent of salivary ACC, and 1 had a mixed pattern. The MYB rearrangement was detected in 2 (29%) of 7 ACC-like carcinomas but in none (0%) of the 5 PBCCs with a prominent solid pattern. True ACCs can arise in the prostate as is evidenced by the presence of the characteristic MYB rearrangement. When dealing with malignant basaloid proliferations in the prostate, recommendations to consolidate ACCs with other tumor types may need to be reassessed, particularly in light of the rapidly advancing field of biologic therapy where the identification of tumor-specific genetic alterations presents novel therapeutic targets.

Prostate adenocarcinomas aberrantly expressing p63 are molecularly distinct from usual-type prostatic adenocarcinomas

We have described a rare group of prostate adenocarcinomas that show aberrant expression of p63, a protein strongly expressed in prostatic basal cells and absent from usual-type acinar prostate cancers. The partial basal-like immunophenotype of these tumors is intriguing in light of the persistent debate surrounding the cell-of-origin for prostate cancer; however, their molecular phenotype is unknown. We collected 37 of these tumors on radical prostatectomy and biopsy and assessed subsets for a diverse panel of molecular markers. The majority of p63-expressing tumors were positive for the ΔNp63 isoform (6/7) by immunofluorescence and p63 mRNA (7/8) by chromogenic in situ hybridization. Despite p63 positivity, these tumors uniformly expressed luminal-type cytokeratin proteins such as CK18 (13/13), CK8 (8/8), and markers of androgen axis signaling commonly seen in luminal cells, including androgen receptor (10/11), NKX3.1 (8/8), and prostein (12/13). Conversely, basal cytokeratins such as CK14 and CK15 were negative in all cases (0/8) and CK5/6 was weakly and focally positive in 36% (4/11) of cases. Pluripotency markers including β-catenin, Oct4, and c-kit were negative in p63-expressing tumors (0/11). Despite nearly universal expression of androgen receptor and downstream androgen signaling targets, p63-expressing tumors lacked ERG rearrangements by fluorescence in situ hybridization (0/14) and ERG protein expression (0/37). No tumors expressed SPINK1 or showed PTEN protein loss (0/19). Surprisingly, 74% (14/19) of p63-expressing tumors expressed GSTP1 protein at least focally, and 33% (2/6) entirely lacked GSTP1 CpG island hypermethylation by bisulfite sequencing. In contrast to usual prostatic adenocarcinomas, prostate tumors with p63 expression show a mixed luminal/basal immunophenotype, uniformly lack ERG gene rearrangement, and frequently express GSTP1. These data strongly suggest that p63-expressing prostate tumors represent a molecularly distinct subclass and further study of this rare tumor type may yield important insights into the role of p63 in prostatic biology and the prostate cancer cell-of-origin.

Female bladder ectopic skene glands: one case report and literature review

Objective To investigate the pathological and immunohistochemical characteristics of female bladder ectopic skene glands. Methods A female with bladder tumor was treated in our hospital in May 2013. Preoperative sonography revealed a 0.9 cm×0.6 cm round solid mass in the bottom of bladder wall. Mass was hypoechoic homogeneous with regular shape, blood flow within the mass was noted. The tumor was treated with transurethral resection. Routine pathological examination suggested bladder ectopic Skene glands. Immunohistochemical stains for prostate specific antigen (PSA), prostate spectific acid phosphatase (PSAP), androgen receptor (AR), estrogen receptor (ER), CD10,cytokeratin 14 (CK14), cytokeratin 18 (CK18), P63, high molecular weight cytokeratin (34βE12), α-methylacyl-CoA racemase (AMACR/p504s) were further performed. Results Routine pathological examination showed prostate glands composed of prostate gland epithelial cells and basal cells in a submucosal location. Immunohistochemical stains showed: PSA –, PSAP + , AR + , ER –, CD10 + , CK18 + , CK14 –, P63 + , 34βE12 + , AMACR –. Conclusions Routine pathological examination combined with immunohistochemical stains such as PSA, PSAP, and others, can be used to diagnose ectopic Skene glands disease. Female bladder ectopic Skene glands is a benign lesion, and the prognosis is good. Key words: Female; Urinary bladder neoplasms; Ectopic skene glands; Ectopic prostate tissue; Pathology

Re-epithelialization resulted from prostate basal cells in canine prostatic urethra may represent the ideal healing method after two-micron laser resection of the prostate

The purpose of this study is to characterize the re-epithelialization of wound healing in canine prostatic urethra and to evaluate the effect of this re-epithelialization way after two-micron laser resection of the prostate (TmLRP). TmLRP and partial bladder neck mucosa were performed in 15 healthy adult male crossbred canines. Wound specimens were harvested at 3 days, and 1, 2, 3, and 4 weeks after operation, respectively. The histopathologic characteristics were observed by hematoxylin and eosin staining. The expression of cytokeratin 14 (CK14), CK5, CK18, synaptophysin (Syn), chromogranin A (CgA), uroplakin, transforming growth factor-β1(TGF-β1), and TGF-β type II receptor in prostatic urethra wound were examined by immunohistochemistry and real-time polymerase chain reaction, respectively. Van Gieson staining was performed to determine the expression of collagen fibers in prostatic urethra and bladder neck would. The results showed that the re-epithelialization of the prostatic urethra resulted from the mobilization of proliferating epithelial cells from residual prostate tissue under the wound. The proliferating cells expressed CK14, CK5, but not CK18, Syn, and CgA and re-epithelialize expressed uroplakin since 3 weeks. There were enhanced TGF-β1 and TGF-β type II receptor expression in proliferating cells and regenerated cells, which correlated with specific phases of re-epithelialization. Compared with the re-epithelialization of the bladder neck, re-epithelialization of canine prostatic urethra was faster, and the expression of collagen fibers was relatively low. In conclusion, re-epithelialization in canine prostatic urethra resulted from prostate basal cells after TmLRP and this re-epithelialization way may represent the ideal healing method from anatomic repair to functional recovery after injury.

DAB2IP regulates cancer stem cell phenotypes through modulating stem cell factor receptor and ZEB1

Cancer stem cell (CSC), the primary source of cancer-initiating population, is involved in cancer recurrence and drug-resistant phenotypes. This study demonstrates that the loss of DAB2IP, a novel Ras-GTPase activating protein frequently found in many cancer types, is associated with CSC properties. Mechanistically, DAB2IP is able to suppress stem cell factor receptor (c-kit or CD117) gene expression by interacting with a newly identified silencer in the c-kit gene. Moreover, DAB2IP is able to inhibit c-kit-PI3K-Akt-mTOR signaling pathway that increases c-myc protein to activate ZEB1 gene expression leading to the elevated CSC phenotypes. An inverse correlation between CD117 or ZEB1 and DAB2IP is also found in clinical specimens. Similarly, Elevated expression of ZEB1 and CD117 are found in the prostate basal cell population of DAB2IP knockout mice. Our study reveals that DAB2IP has a critical role in modulating CSC properties via CD117-mediated ZEB1 signaling pathway.

Epithelial cell lineage specification during prostate organogenesis and regeneration (210.4)

The prostate gland is a particularly interesting system for the investigation of cell lineage specification given the central role of androgen signaling in all aspects of its development and function, as well as its ability to undergo serial regression and regeneration in response to androgen deprivation and restoration. In our previous studies, we have shown that a known regulator of prostate epithelial differentiation, the homeobox gene Nkx3.1, marks a luminal stem cell population that functions during prostate regeneration and is an efficient target for oncogenic transformation in prostate cancer. Genetic lineage‐tracing studies demonstrated that these rare cells which express Nkx3.1 in the absence of testicular androgens (castration‐resistant Nkx3.1‐expressing cells, CARNs) are bipotential and can self‐renew in vivo, and can serve as a cell of origin for prostate cancer. In parallel studies, we have utilized lineage‐tracing and transplantation approaches to explore the stem/progenitor properties of prostate basal cells during regeneration and tissue homeostasis, and observed an unexpected plasticity of basal cells in these assays. We will present our recent findings on prostate lineage specification and discuss their implications with respect to the relationship between epithelial progenitor populations and prostate cancer initiation.