Low concentrations of transforming growth factor-beta-1 induce tubulogenesis in cultured mammary epithelial cells

BACKGROUND: Formation of branching tubes is a fundamental step in the development of glandular organs. To identify extracellular cues that orchestrate epithelial tubulogenesis, we employed an in vitro assay in which EpH4-J3B1A mammary epithelial cells form spheroidal cysts when grown in collagen gels under serum-free conditions, but form branching tubules in the presence of fetal calf serum (FCS). RESULTS: Initial experiments showed that the tubulogenesis-inducing activity of FCS was markedly increased by heating (70°C) or transient acidification to pH3. We therefore hypothesized that the tubulogenic agent was transforming growth factor-beta (TGF-beta), a cytokine that is present in serum in latent form and can be activated by heat or acid treatment. We found indeed that the tubulogenic activity of acidified FCS is abrogated by addition of either SB-431542, a selective inhibitor of the TGF-beta type I receptor, or a neutralizing antibody to TGF-beta-1. On the other hand, addition of low concentrations (20–100 pg/ml) of exogenous TGF-beta-1 recapitulated the effect of acidified FCS in inducing morphogenesis of hollow tubes. In contrast, higher concentrations of TGF-beta-1 induced the formation of thin cellular cords devoid of a detectable lumen. To gain insight into the mechanisms underlying TGF-beta-1-induced tube formation, we assessed the potential role of matrix metalloproteinases (MMPs). By western blot and gelatin zymography, we observed a dose-dependent increase in MMP-9 upon TGF-beta-1 treatment. Tube formation was suppressed by a synthetic broad-spectrum metalloproteinase inhibitor, by recombinant tissue inhibitor of metalloproteinases-2 (TIMP-2) and by a selective inhibitor of MMP-9, indicating that this morphogenetic process requires the activity of MMP-9. CONCLUSION: Altogether, our results provide evidence that, at low concentrations, TGF-beta-1 promotes MMP-dependent branching tubulogenesis by mammary epithelial cells in vitro, and suggest that it plays a similar role during mammary gland development in vivo

Primary cilia control the maturation of tubular lumen in renal collecting duct epithelium

The key role of the primary cilium in developmental processes is illustrated by ciliopathies resulting from genetic defects of its components. Ciliopathies include a large variety of dysmorphic syndromes that share in common the presence of multiple kidney cysts. These observations suggest that primary cilia may control morphogenetic processes in the developing kidney. In this study, we assessed the role of primary cilium in branching tubulogenesis and/or lumen development using kidney collecting duct-derived mCCDN21 cells that display spontaneous tubulogenic properties when grown in collagen-Matrigel matrix. Tubulogenesis and branching were not altered when cilium body growth was inhibited by Kif3A or Ift88 silencing. In agreement with the absence of a morphogenetic effect, proliferation and wound-healing assay revealed that neither cell proliferation nor migration were altered by cilium body disruption. The absence of cilium following Kif3A or Ift88 silencing in mCCDN21 cells did not alter the initial stages of tubular lumen generation while lumen maturation and enlargement were delayed. This delay in tubular lumen maturation was not observed after Pkd1 knockdown in mCCDN21 cells. The delayed lumen maturation was explained by neither defective secretion or increased reabsorption of luminal fluid. Our results indicate that primary cilia do not control early morphogenetic processes in renal epithelium. Rather, primary cilia modulate tubular lumen maturation and enlargement resulting from luminal fluid accumulation in tubular structures derived from collecting duct cells

Clinicopathological characteristics of urothelial bladder cancer in patients less than 40 years old

International audienceUrothelial bladder cancer (UBC) is rare in young patients and as a result little information as to tumor type and clinical course are available. We present clinicopathological data of a large series of patients less than 40 years with bladder carcinoma. We included in this retrospective study covering the period from 1992 to 2013 patients less than 40 years with a first diagnosis of bladder cancer. Lesions were classified according to the WHO 2004 classification by uropathologists of ten centers. Stage, grade, multifocality, smoking habits, recurrence, and survival were studied. The cohort comprised of 152 patients, 113 males and 39 females with a mean age of 33.2 years. The large majority of the patients (142) was diagnosed with an urothelial carcinoma, the ten others with various histopathological diagnoses. In the age group less than 30 years old, 40.3 % of the cases concerned a papillary urothelial neoplasia of low malignant potential (PUNLMP). In the age group over 30 years, the proportion of PUNLMP decreased to 27.2 %. Only 5.6 % of the UBC was associated with carcinoma in situ. In 14.1 %, a high grade muscle invasive UC was found; 7.0 % had lymph node and 4.9 % distant metastasis at time of presentation. Four patients presented with a history of schistosomiasis; all had an infiltrating carcinoma. After initial resection, 36 patients relapsed, 17 % as PUNLMP, 53 % as pTa low grade, and 30 % as pTa-pT2 high grade UC. During follow-up, 6 % of the patients died. PUNLMP is the most frequent entity in this patient group. It is important that the PUNLMP entity is maintained in future classification systems

The subclassification of papillary renal cell carcinoma does not affect oncological outcomes after nephron sparing surgery

International audienceObjectives To evaluate the oncological outcomes of papillary renal cell carcinoma (pRCC) following nephron sparing surgery (NSS) and to determine whether the subclassification type of pRCC could be a prognostic factor for recurrence, progression, and specific death. Materials and methods An international multicentre retrospective study involving 19 institutions and the French network for research on kidney cancer was conducted after IRB approval. We analyzed data of all patients with pRCC who were treated by NSS between 2004 and 2014. Results We included 486 patients. Tumors were type 1 pRCC in 369 (76 %) cases and type 2 pRCC in 117 (24 %) cases. After a mean follow-up of 35 (1–120) months, 8 (1.6 %) patients experienced a local recurrence, 12 (1.5 %) had a metastatic progression, 24 (4.9 %) died, and 7 (1.4 %) died from cancer. Patients with type I pRCC had more grade II (66.3 vs. 46.1 %; p \textless 0.001) and less grade III (20 vs. 41 %; p \textless 0.001) tumors. Three-year estimated cancer-free survival (CFS) rate for type 1 pRCC was 96.5 % and for type 2 pRCC was 95.1 % (p = 0.894), respectively. Three-year estimated cancer-specific survival rate for type 1 pRCC was 98.4 % and for type 2 pRCC was 97.3 % (p = 0.947), respectively. Tumor stage superior to pT1 was the only prognostic factor for CFS (HR 3.5; p = 0.03). Conclusion Histological subtyping of pRCC has no impact on oncologic outcomes after nephron sparing surgery. In this selected population of pRCC tumors, we found that tumor stage is the only prognostic factor for cancer-free surviva