Probes for INS

Treatment with androgen-targeted therapies can induce upregulation of epithelial plasticity pathways. Epithelial plasticity is known to be important for metastatic dissemination and therapeutic resistance. The goal of this study is to elucidate the functional consequence of induced epithelial plasticity on AR regulation during disease progression to identify factors important for treatment-resistant and metastatic prostate cancer. We pinpoint the epithelial plasticity transcription factor, Snail, at the nexus of enzalutamide resistance and prostate cancer metastasis both in preclinical models of prostate cancer and in patients. In patients, Snail expression is associated with Gleason 9-10 high-risk disease and is strongly overexpressed in metastases as compared to localized prostate cancer. Snail expression is also elevated in enzalutamide-resistant prostate cancer cells compared to enzalutamide-sensitive cells, and downregulation of Snail re-sensitizes enzalutamide-resistant cells to enzalutamide. While activation of Snail increases migration and invasion, it is also capable of promoting enzalutamide resistance in enzalutamide-sensitive cells. This Snail-mediated enzalutamide resistance is a consequence of increased full-length AR and AR-V7 expression and nuclear localization. Downregulation of either full-length AR or AR-V7 re-sensitizes cells to enzalutamide in the presence of Snail, thus connecting Snail-induced enzalutamide resistance directly to AR biology. Finally, we demonstrate that Snail is capable of mediating-resistance through AR even in the absence of AR-V7. These findings imply that increased Snail expressionduring progression to metastatic disease may prime cells for resistance to AR-targeted therapies by promoting AR activity in prostate cancer.

Secreted protein acidic and rich in cysteine (SPARC) plays an essential role in tumor invasion and metastasis. The present work was undertaken to detect expression of SPARC mRNA in phyllodes tumors (PTs) and its association with SPARC protein expression. This study also evaluated expression of SPARC mRNA and its correlation between grade and clinical behavior of PTs. In addition, we assessed in PTs the association of expression of SPARC with that of matrix metalloproteinase (MMP)-2 and of MMP-9. SPARC mRNA expression was determined by RNAscope in situ hybridization (ISH) in 50 benign, 22 borderline, and 10 malignant PTs using a tissue microarray. Furthermore, we applied immunohistochemistry (IHC) to examine expression of SPARC, MMP-2, and MMP-9. SPARC mRNA appeared to be concentrated mainly in the stromal compartment of PTs. IHC staining patterns of SPARC protein showed concordance with SPARC mRNA ISH results. Stromal SPARC expression increased continuously as PTs progress from benign through borderline to malignant PTs, both at mRNA (using ISH) (P = 0.044) and protein level (using IHC) (P = 0.000). The recurrence percentage was higher in the stromal SPARC mRNA or protein-positive group than in the SPARC-negative group but this difference was not statistically significant. Stromal SPARC mRNA and protein expression was associated with PT grade and correlated with MMP-2 expression. These results indicate that SPARC-mediated degradation of the extracellular matrix, and its possible association with MMPs, might contribute to progression of PTs.

Abstract

Gametogenetin binding protein 2 (GGNBP2) is an evolutionarily conserved zinc finger protein. Although Ggnbp2 null embryos in the B6 background died due to a defective placenta, 6.8% of Ggnbp2 null mice in the B6/129 mixed background were viable and continued to adulthood. Adult Ggnbp2 null males were sterile with smaller testes and an azoospermic phenotype, while mutant females were fertile. Histopathological analysis of 2-month-old Ggnbp2 null testes revealed absence of mature spermatozoa in the seminiferous tubules and epididymides and reduction of the number of spermatids. Ultrastructural analysis indicated dramatic morphological defects of developing spermatids in the Ggnbp2 null testes, including irregularly shaped acrosomes, acrosome detachment, cytoplasmic remnant, ectopic manchette and ill-formed head shape in both elongating and elongated spermatids. However, the numbers of spermatogonia, spermatocytes, Leydig cells and Sertoli cells in Ggnbp2 null testes did not significantly differ from the wild-type (WT) siblings. Gonadotropins, testosterone and the blood-testis barrier were essentially unaffected. Western blot analyses showed increases in α-E-catenin, β-catenin and N-cadherin, decreases in E-cadherin, afadin and nectin-3, and were unchanged in vinculin, nectin-2, FAK and integrin-β1 protein levels in Ggnbp2 null testes compared to WT siblings. Together, this study demonstrates that GGNBP2 is critically required for maintenance of the adhesion integrity of the adlumenal germ epithelium and is indispensable for normal spermatid transformation into mature spermatozoa in mice.

Abstract

AIM:

To determine whether intestinal expression of guanylate cyclase activator 2A (GUCA2A) and guanylate cyclase activator 2B (GUCA2B) genes is regulated in obese humans following Roux-en-Y gastric bypass (RYGB), and to evaluate the corresponding guanylin (GN) and uroguanylin (UGN) peptides for potentially contributing to the beneficial metabolic effects of RYGB.

METHODS:

Enteroendocrine cells were harvested peri- and post-RYGB, and GUCA2A/GUCA2B mRNA expression was compared. GN, UGN and their prohormones (proGN, proUGN) were administered subcutaneously in normal-weight mice to evaluate effects on food intake and glucose regulation. The effect of pro-UGN or UGN overexpression, using adeno-associated virus (AAV) vectors, was assessed in diet-induced obese (DIO) mice. Intracerebroventricular administration of GN and UGN was performed in rats for assessment of putative centrally mediated effects on food intake. GN and UGN, as well as their prohormones, were evaluated for effects on glucose-stimulated insulin secretion (GSIS) in rat pancreatic islets and perfused rat pancreas.

RESULTS:

GUCA2A and GUCA2B mRNA expression was significantly upregulated in enteroendocrine cells after RYGB. Peripheral administration of guanylins or prohormones did not influence food intake, oral glucose tolerance, and GSIS. Central administration of GN and UGN did not affect food intake in rats. Chronic AVV-mediated overexpression of UGN and proUGN had no effect on body weight or glucose homeostasis in DIO mice.

CONCLUSION:

GN and UGN, as well as their prohormones, do not seem to play a significant role in body weight regulation and glycemic control, suggesting that guanylin-family peptides do not show promise as targets for the treatment of obesity or diabetes.

Hepatocytes are replenished gradually during homeostasis and robustly after liver injury1, 2. In adults, new hepatocytes originate from the existing hepatocyte pool3-8, but the cellular source of renewing hepatocytes remains unclear. Telomerase is expressed in many stem cell populations, and mutations in telomerase pathway genes have been linked to liver diseases9-11. Here we identify a subset of hepatocytes that expresses high levels of telomerase and show that this hepatocyte subset repopulates the liver during homeostasis and injury. Using lineage tracing from the telomerase reverse transcriptase (Tert) locus in mice, we demonstrate that rare hepatocytes with high telomerase expression (TERTHigh hepatocytes) are distributed throughout the liver lobule. During homeostasis, these cells regenerate hepatocytes in all lobular zones, and both self-renew and differentiate to yield expanding hepatocyte clones that eventually dominate the liver. In response to injury, the repopulating activity of TERTHigh hepatocytes is accelerated and their progeny cross zonal boundaries. RNA sequencing shows that metabolic genes are downregulated in TERTHigh hepatocytes, indicating that metabolic activity and repopulating activity may be segregated within the hepatocyte lineage. Genetic ablation of TERTHigh hepatocytes combined with chemical injury causes a marked increase in stellate cell activation and fibrosis. These results provide support for a 'distributed model' of hepatocyte renewal in which a subset of hepatocytes dispersed throughout the lobule clonally expands to maintain liver mass.

Breast cancer (BC) is one of the primary tumors with high incidence in women. The purpose of this study was to investigate the role of LINC00473 and underlying mechanisms in BC. Expression pattern of LINC00473 was analyzed using qRT-PCR (quantitative real-time polymerase chain reaction) assays in BC tissues and cells. Overexpression or knockdown of LINC00473 in vitro and functional experiments were performed to study its effects on BC cells. Target prediction, luciferase assays, RNA fluorescence in situ hybridization and RNA immunoprecipitation were used to verify the role of LINC00473 as a competing endogenous RNA. The impact of LINC00473 on tumor growth was also evaluated using a xenograft model. In our study, we found that LINC00473 was highly expressed in BC tissues and cells, and the elevated expression was correlated with shorter overall survival in patients with BC. Furthermore, knockdown of LINC00473 significantly inhibited the capacity of proliferation, invasion and migration of BC cells. Animal experiment suggested that silencing LINC00473 could significantly inhibit the tumor growth. Following experiments revealed that LINC00473 may function as a competing endogenous RNA to regulate the expression of Mitogen-Activated Protein Kinase 1 (MAPK1) through competition for miR-198. Thus, increased expression of LINC00473 in breast cancer tissues is linked to poor prognosis. LINC00473 may function as an endogenous completive RNA by sponging miR-198 to regulate MAPK1 expression. Findings of our study contributed to the basis for further exploring the application of LINC00473 as a prognostic and diagnostic biomarker.

The presence and extent of cribriform pattern of prostate cancer portend recurrence and cancer death. Therelative expressions within this morphology of the prognostically adverse loss of PTEN, and the downstream inactivation of cell cycle inhibitor p27/Kip1 had been uncertain. In this study, we examined 52 cases of cribriform cancer by immunohistochemistry (IHC) for PTEN, p27, and CD44 variant (v)7/8, and a subset of 17 casesby chromogenic in situ hybridization (ISH) using probe for PTEN or CDKN1B (gene for p27). The fractions of epithelial pixels positive by IHC and ISH were digitally assessed for benign acini, high grade prostatic intraepithelial neoplasia (PIN), and 8 morphological patterns of cancer. Immunostaining results demonstrated that: 1. PTEN loss was significant for fused small acini, cribriform-central cells, small cribriform acini, and Gleason grade 5 cells in comparison with other acini. 2. p27 loss was significant only for cribriform-peripheral cells; and borderline-significant for fused small acini in comparison with benign acini. 3. CD44v7/8 showed expression loss in cribriform-peripheral cells; other comparisons were not significant. ISH showed thatcribriform cancer had significant PTEN loss normalized to benign acini (P < .02), while Gleason 3 cancer or fused small acini did not. With CDKN1B, the degree of signal loss among various cancer morphologies was insignificant. In conclusion, molecular disparities emerged between the fused small acini and cribriform patterns of Gleason 4 cancer. PTEN or p27 loss as prognostic factors demand distinct assessment in the varieties of Gleason 4 cancer, and in the biphenotypic peripheral versus central populations in cribriform structures.