Foxc2 induces Wnt4 and Bmp4 expression during muscle regeneration and osteogenesis.

Proliferation and fusion of myoblasts is a well-orchestrated process occurring during muscle development and regeneration. Although myoblasts are known to originate from muscle satellite cells, the molecular mechanisms that coordinate their commitment toward differentiation are poorly understood. Here, we present a novel role for the transcription factor Forkhead box protein C2 (Foxc2) in regulating proliferation and preventing premature differentiation of activated muscle satellite cells. We demonstrate that Foxc2 expression is upregulated early in activated mouse muscle satellite cells and then diminishes during myogenesis. In undifferentiated C2C12 myoblasts, downregulation of endogenous Foxc2 expression leads to a decrease in proliferation, whereas forced expression of FOXC2 sustains proliferation and prevents differentiation into myotubes. We also show that FOXC2 induces Wnt signaling by direct interaction with the Wnt4 (wingless-type MMTV integration site family member-4) promoter region. The resulting elevated expression of bone morphogenetic protein-4 (Bmp4) and RhoA-GTP proteins inhibits the proper myoblast alignment and fusion required for myotube formation. Interestingly, continuous forced expression of FOXC2 alters the commitment of C2C12 myoblasts toward osteogenic differentiation, which is consistent with FOXC2 expression observed in patients with myositis ossificans, an abnormal bone growth within muscle tissue. In summary, our results suggest that (a) Foxc2 regulates the proliferation of multipotent muscle satellite cells; (b) downregulation of Foxc2 is critical for myogenesis to progress; and (c) sustained Foxc2 expression in myoblast cells suppresses myogenesis and alters their lineage commitment toward osteogenesis by inducing the Wnt4 and Bmp4 signaling pathways.

[RIRS through semi-rigid ureteroscope and holmium laser in the treatment of ureteral stones retropulsion]. / La RIRS di necessità con ureteroscopio semirigido e laser ad olmio nel trattamento della calcolosi ureterale retropulsa.

Retrograde displacement of ureteral stones into the renal cavities during ureteroscopic lithotripsy represents a frequent and adverse event that leads to additional procedures (ESWL, PCNL, Retrograde Intra-renal lithotripsy with flexible instruments, DJ stent placement and subsequent EWSL) to obtain full clearence of calculi. All these procedures require a further time of treatment. Between 1/2008 and 3/2009, a total of 48 patients harbouring proximal (21 cases) and distal (27 cases) ureteral stones underwent Holmium Laser lithotripsy. In 3 patients previous percutaneous nephrostomy was performed to drain the excretory way. In 12 cases (25%) stone retropulsion occurred; in 3 patients in the upper calix and in 5 in the renal pelvis. Only in 4 cases the stone migrated in the lower or medium calix. In 8 cases we attempted the immediate treatment of intrarenal displaced stones by advancing the semi-rigid instrument into the renal cavities. In 2 cases the treatment aborted because of the shortness of ureteroscope. The instillation of lubricating lidocaine jelly prevented in 3 cases furher displacement of stone. Washing with saline solution through nephrostomic catheter allowed an effective mobilization of stone and an easy lasertripsy. RIRS was successful in 4 cases. When flexible devices or immediate ESWL are not available, rigid or semi-rigid retrograde lithotripsy with holmium laser immediately performed after ureteral stone displacement represents a safe and effective method to treat displaced stones. Several tricks are required to obtain a good stone-free rate.

[Urethral recurrence of invasive carcinoma following BCG treatment for bladder Ca in situ]. / Recidiva uretrale di Ca infiltrante dopo trattamento con BCG per Ca in situ vescicale.

CIS is a flat, high-grade, non-invasive microscopic urothelial carcinoma. It is considered a precursor of invasive bladder cancer. CIS is classified as primary, secondary or concurrent, when occurred as isolated CIS without cuncurrent papillary tumors, or detected during the follow-up of patients with a previous papillary tumor, or finally in the presence of bladder neoplasm. BCG is widely established as the treatment of choice for CIS with a success rate of approximately 70%. BCG reduces the risk of progression of CIS into invasive carcinoma in 30 to 50% of cases. Direct and prolonged contact between the urothelium and BCG is a prerequisite for successful therapy. Discovery of CIS in the prostatic or membranous urethra represents an ominous sign. CIS may be present only in the epithelial lining of the prostatic urethra or in the ducts, or in the worst case it may be found in the prostatic tissue stroma. Urethral involvement by CIS is at high risk of tumor progression and development of metastases due to reduced thickness of lamina propria and absence of muscolaris mucosa. 83 patients, enrolled from 1/1996 to 12/2005 at our urological department with CIS: primary (focal and multifocal) in 25, secondary in 7 and cuncurrent in 51 (associated with T1bG3 cancer in 37 cases), and urethral CIS in 5 and conservatively treated by TUR and intravescical instillations of BCG, 4 developed afterwords only invasive cancer of the urethra in the absence of bladder involvement. In 2 cases cancer arised from the prostatic fossa after TURP, in 1 from membranous urethra and in the last from prostatic ducts. Among the 4 patients, 3 were treated by cystoprostatourethrectomy and Platinum-based chemotherapy, 1 refused surgical treatment. Two patients died for disseminated disease. 1 patient is alive at 60-month's follow-up. In the last patient cancer relapsed at 36-month's follow-up. We conclude that prostatic/urethral involvement during follow-up after successful intravesical treatment with BCG in CIS represents a high risk of developing invasive and incontrolled cancer. A careful watch is recommended in these patients.

Structure of the lymphatic microcirculation in the human urinary bladder with different intraluminal pressure and distension.

The localization, morphology and fine structure of initial lymphatic vessels in the mucosa of the empty and distended urinary bladder were studied. Endoscopic transurethral biopsies of the empty (collapsed) bladder showed under light and electron microscopy numerous intramural lymphatics with a dilated lumen and thin profile. Contacts between endothelial cells were single, overlapping, interlocking, and open while the perivascular connective tissue was filled by fascicles of collagen fibers. In the most superficial layer (subepithelial mucosa), lymphatics were not seen. Biopsies obtained under elevated intraluminal pressure and distension showed on light and electron microscopy lymphatic vessels with small lumens characteristically reduced to irregular slits. Endothelial cell contacts were simple or overlapping; open junctions were rare. The perivascular connective tissue was dense and collagen and elastic fibers often abutted one another. These findings support that with a distended or expanded urinary bladder, the effect of increased intraluminal pressure on the superficial (mucosal) layer radially pulls on the connective tissue that in turn compresses the initial lymphatics thereby restricting lymph transport.

[Neoadjuvant chemotherapy of locally advanced tumors of the bladder: preliminary experience]. / Chemioterapia neoadiuvante nei tumori vescicali localmente avanzati: esperienza iniziale.

From february 1988 to march 1989, 6 patients with locally advanced bladder cancer (T3b-T4, N0-N1, M0) were treated with 4 courses of neoadjuvant MP chemotherapy (methotrexate 300 mg/mq. + cisplatinum 100 mg/mq). In two patients chemotherapy was stopped because minimal or no response after two courses. Partial response (RP) was achieved in three patients (50%). Two patients died 2 and 5 month later. One patients developed metastases at 11 month. The remaining three cases showed NED at 3, 4 and 15 months of follow-up. In the same period 4 patients with metastatic bladder tumor were treated with M-VAC chemotherapy according to Yagoda before the cystectomy. M-VAC obtained a complete response in one case, and PR in 3 cases. All the metastases showed evidence of objective tumor regression. Reduction of bone pain was observed in one case. One patient died 15 months later with bone massive involvement. Another patient developed invasive tumor at 13 months. Two patients were disease-free at 3 and 5 months, respectively. Toxicity was more frequent in patient treated with M-VAC than with MP chemotherapy. M-VAC, we believe, represents a reliable neoadjuvant treatment of advanced metastatic bladder cancer.