Joseph Sirintrapun

Suppression of Tak1 promotes prostate tumorigenesis.

More than 30% of primary prostate cancers contain a consensus deletion of an approximately 800 kb locus on chromosome 6q15.1. The MAP3K7 gene, which encodes TGF-β activated kinase-1 (Tak1), is a putative prostate tumor suppressor gene within this region whose precise function remains obscure. In this study, we investigated the role of Tak1 in human and murine prostate cancers. In 50 well-characterized human cancer specimens, we found that Tak1 expression was progressively lost with increasing Gleason grade, both within each cancer and across all cancers. In murine prostate stem cells and Tak1-deficient prostatic epithelial cells, Tak1 loss increased proliferation, migration, and invasion. When prostate stem cells attenuated for Tak1 were engrafted with fetal urogenital mesenchyme, the histopathology of the grafts reflected the natural history of prostate cancer leading from prostatic intraepithelial neoplasia to invasive carcinoma. In the grafts containing Tak1-suppressed prostate stem cells, p38 and c-jun-NH(2)-kinase activity was attenuated and proliferation was increased. Together, our findings functionally validate the proposed tumor suppressor role of Tak1 in prostate cancer.

Halofuginone-Coated Urethral Catheters Prevent Periurethral Spongiofibrosis in a Rat Model of Urethral Injury

BACKGROUND AND PURPOSE Urethral strictures are from periurethral spongiofibrosis that develops as a result of urethral trauma, disease, or iatrogenic injury. The spongy tissue that surrounds the strictured urethra has an altered ratio of collagen, with increased collagen type I relative to type III. We evaluated the ability of a urethral catheter that was coated with halofuginone (HF), a potent type I collagen inhibitor, to prevent spongiofibrosis formation in a rat model. MATERIALS AND METHODS HF was coated on silicone catheters and release kinetics were measured. Success of impregnation was evaluated with scanning electron microscopy, serial weights, and drug elution data. Urethral strictures were induced in rats using electrocautery. Half the animals had placement of an HF-coated catheter while the others had uncoated silicone controls. Animals were sacrificed at predetermined time points, and urethral tissue was either processed for staining with Masson trichrome and anti-alpha-1 collagen or digested to determine HF concentration. Serum drug levels were also determined in treated animals. Slides were graded by a pathologist who was blinded to treatment to determine collagen deposition. RESULTS HF was coated successfully on silicone catheters. Local urethral concentration of HF was tenfold higher than serum concentration in treated rats. Animals with HF-coated catheters had no new type I collagen deposition after urethral injury. Control animals had increased periurethral collagen type I deposition, typical of urethral stricture formation. CONCLUSIONS HF can be coated successfully on silicone catheters. HF successfully inhibits periurethral type I collagen deposition after urethral injury. This may become an important therapy to prevent urethral stricture formation or recurrence after endoscopic therapy.

Perioperative systemic chemotherapy for appendiceal mucinous carcinoma peritonei treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy

The role of systemic chemotherapy (SC) in conjunction with cytoreductive surgery (CS) with hyperthermic intraperitoneal chemotherapy (HIPEC) in appendiceal mucinous carcinoma peritonei (MCP) is unknown.

Halofuginone infused keratin hydrogel attenuates adhesions in a rodent cecal abrasion model.

BACKGROUND Postoperative adhesion formation continues to be a significant surgical complication, and methods for preventing abdominopelvic adhesions remain limited. Halofuginone (HF) is a type-1 collagen synthesis inhibitor and may enhance the effects of a physical barrier in preventing adhesion formation. We evaluated the effectiveness of a HF infused keratin hydrogel on preventing adhesions in a rat cecal abrasion model. MATERIAL AND METHODS Laparotomy and standardized cecal abrasion was performed on 58 retired-breeder Sprague Dawley female rats to induce intra-abdominal adhesions. Rats were randomized to: no treatment; Interceed absorbable adhesion barrier; keratin hydrogel alone; or keratin hydrogel infused with 22 μg/mL of HF. Necropsies were performed at postop d-14 to assess the extent and tenacity of adhesions and grade histologic inflammation and fibrosis using a standard scoring system. Serum, liver, kidneys, and lungs were harvested to evaluate tissue HF concentrations. Protein and drug elution curves were generated to assess the release of HF from the hydrogel. RESULTS Treatment with Keratin-HF hydrogel resulted in significantly fewer abdominal adhesions than any other treatment, and significantly less dense adhesions compared with Interceed or keratin hydrogel alone. Subset histologic analysis did not reveal qualitative differences. HF was undetectable in serum and kidneys, and detected at negligible concentrations in liver and lungs. Keratin-HF hydrogel drug release in phosphate-buffered solution (PBS) was sustained over 7 d and correlated with keratin protein degradation. CONCLUSIONS Keratin-HF hydrogel is a novel therapeutic agent that may provide a better method for preventing the development of postoperative adhesions using a combined physical barrier and pharmacologic approached.

Silibinin prevents prostate cancer cell‐mediated differentiation of naïve fibroblasts into cancer‐associated fibroblast phenotype by targeting TGF β2

Tumor microenvironment (TM) is an essential element in prostate cancer (PCA), offering unique opportunities for its prevention. TM includes naïve fibroblasts that are recruited by nascent neoplastic lesion and altered into ‘cancer‐associated fibroblasts’ (CAFs) that promote PCA. A better understanding and targeting of interaction between PCA cells and fibroblasts and inhibiting CAF phenotype through non‐toxic agents are novel approaches to prevent PCA progression. One well‐studied cancer chemopreventive agent is silibinin, and thus, we examined its efficacy against PCA cells‐mediated differentiation of naïve fibroblasts into a myofibroblastic‐phenotype similar to that found in CAFs. Silibinins direct inhibitory effect on the phenotype of CAFs derived directly from PCA patients was also assessed. Human prostate stromal cells (PrSCs) exposed to control conditioned media (CCM) from human PCA PC3 cells showed more invasiveness, with increased alpha‐smooth muscle actin (α‐SMA) and vimentin expression, and differentiation into a phenotype we identified in CAFs. Importantly, silibinin (at physiologically achievable concentrations) inhibited α‐SMA expression and invasiveness in differentiated fibroblasts and prostate CAFs directly, as well as indirectly by targeting PCA cells. The observed increase in α‐SMA and CAF‐like phenotype was transforming growth factor (TGF) β2 dependent, which was strongly inhibited by silibinin. Furthermore, induction of α‐SMA and CAF phenotype by CCM were also strongly inhibited by a TGFβ2‐neutralizing antibody. The inhibitory effect of silibinin on TGFβ2 expression and CAF‐like biomarkers was also observed in PC3 tumors. Together, these findings highlight the potential usefulness of silibinin in PCA prevention through targeting the CAF phenotype in the prostate TM.

Non-covalent assembly of meso-tetra-4-pyridyl porphine with single-stranded DNA to form nano-sized complexes with hydrophobicity-dependent DNA release and anti-tumor activity

UNLABELLED DNA and porphyrin based therapeutics are important for anti-cancer treatment. The present studies demonstrate single-stranded DNA (ssDNA) assembles with meso-tetra-4-pyridyl porphine (MTP) forming porphyrin:DNA nano-complexes (PDN) that are stable in aqueous solution under physiologically relevant conditions and undergo dissociation with DNA release in hydrophobic environments, including cell membranes. PDN formation is DNA-dependent with the ratio of porphyrin:DNA being approximately two DNA nucleobases per porphyrin. PDN produce reactive oxygen species (ROS) in a light-dependent manner under conditions that favor nano-complex dissociation in the presence of hydrophobic solvents. PDN induce light-dependent cytotoxicity in vitro and anti-tumor activity towards bladder cancer xenografts in vivo. Light-dependent, PDN-mediated cell death results from ROS-mediated localized membrane damage due to lipid peroxidation with mass spectrometry indicating the generation of the lipid peroxidation products 9- and 13-hydroxy octadecanoic acid. Our results demonstrate that PDN have properties useful for therapeutic applications, including cancer treatment. FROM THE CLINICAL EDITOR In this study, porphyrin-DNA nanocomplexes were investigated as anti-cancer therapeutics inducing ROS production in a light-dependent manner. Efficacy is demonstrated in vitro as well as a in a bladder cancer xenograft model.

Experimental testicular tissue banking to generate spermatogenesis in the future: A multidisciplinary team approach.

Spermatogonial stem cell (SSC) loss due to cancer treatment, developmental disorder or genetic abnormality may cause permanent infertility. Cryopreservation of ejaculated sperm is an effective method of fertility preservation in adult males at risk of infertility. However this is not an option in pre-pubertal boys because spermatogenesis has not yet started, and it is difficult in adolescents who are not sexually mature. Therefore testicular tissue cryopreservation to preserve SSCs for future generation of spermatogenesis, either in vivo or in vitro, could be an option for these groups of patients. Although SSC transplantation has been successful in several species including non-human primates, it is still experimental in humans. There are several remaining concerns which need to be addressed before initiating trials of human SSC autotransplantation. Establishment of a testicular tissue banking system is a fundamental step towards using SSC technology as a fertility preservation method. It is important to understand the consultation, harvesting the testicular tissue, histological evaluation, cryopreservation, and long term storage aspects. We describe here a multidisciplinary approach to establish testicular tissue banking for males at risk of infertility.

Amiodarone hepatotoxicity with absent phospholipidosis and steatosis: a case report and review of amiodarone toxicity in various organs.

We present the first description of amiodarone toxicity in the liver without phospholipidosis or steatosis. In doing so, we will review the various effects of amiodarone toxicity in various organs. The patient is a young adult who had cardiac reconstruction as a child for transposition of the great vessels. A needle biopsy was taken due to elevated liver enzymes. Her ALT was 188 U/L (5–50) and AST 162 U/L (5–50). Alkaline phosphatase, total bilirubin, protein, and albumin were within normal limits. A serologic panel for viral hepatitis was negative. Antinuclear antibodies were positive at 260; however, anti-smooth muscle antibody and anti-mitochondrial antibody were negative. A protein electrophoresis showed a slightly elevated beta globulin 2 level of 0.5. Quantitative immunoglobulin levels were within normal limits except for a slightly elevated IgA 409 mg/dL (60–350). Liver ultrasound was unremarkable. The clinical differential was broad and included hepatic congestion along with autoimmune hepatitis. Sections showed only ballooned hepatocytes with Mallory-Denk bodies and perisinusoidal fibrosis. Arrival to the diagnosis was possible only after careful review of the patients medications. After discontinuation of amiodarone, the patients liver enzymes returned to normal levels.