Supplementary Table 3 from Randomized Double-Blind Trial of Sulindac and Etodolac to Eradicate Aberrant Crypt Foci and to Prevent Sporadic Colorectal Polyps

Glutathione-S transferase P1 (GSTP1) is one of the glutathione-S transferase isozymes that belong to a family of phase II metabolic isozymes. The unique feature of GSTP1 compared with other GST isozymes is its relatively high expression in malignant tissues. Thus, clinically, GSTP1 serves as a tumor marker and as a refractory factor against certain types of anticancer drugs through its primary function as a detoxifying enzyme. Additionally, recent studies have identified a chaperone activity of GSTP1 involved in the regulation the function of various intracellular proteins, including factors of the growth signaling pathway. In this review, we will first describe the function of GSTP1 and then extend the details onto its role in the mitogen-activated protein kinase signal pathway, referring to the results of our recent study that proposed a novel autocrine signal loop formed by the CRAF/GSTP1 complex in mutated KRAS and BRAF cancers. Finally, the possibilities of new therapeutic approaches for these cancers by targeting this complex will be discussed.

Background and Aim In chronic hepatic diseases where treatment strategies are not available, deposited fibrotic tissues deteriorate the intrinsic regeneration capacity of the liver by creating special restrictions. Thus, if the anti-fibrosis modality is efficiently applied, the regeneration capacity of the liver should be reactivated even in such refractory hepatic diseases. Methods Rat liver fibrosis was induced by dimethyl-nitrosamine (DMN). Another liver fibrosis model was established in CCl4 treated Sox9CreERT2ROSA26: YFP mice. To resolve hepatic fibrosis, vitamin A-coupled liposomes containing siRNA HSP47 (VA-liposome siHSP47) were employed. EpCAM + hepatic progenitor cells from GFP rats were transplanted to DMN rat liver to examine their trans-differentiation into hepatic cells after resolution of liver fibrosis. Results Even under continuous exposure to such strong hepatotoxin as DMN, rats undergoing VA-liposome siHSP47 treatment showed an increment of DNA synthesis of hepatocytes with the concomitant restoration of impaired liver weight and normalization of albumin levels. These results were consistent with the observation that GFP + EpCAM hepatic progenitor cells transplanted to DMN rat liver, trans-differentiated into GFP + mature hepatic cells after VA-liposome siHSP47 treatment. Another rodent model also proved regeneration potential of the fibrotic liver in CCl4 administered Sox9CreERT2ROSA26: YFP mice, VA-liposome siHSP47 treatment-induced restoration of liver weight and trans-differentiation of YEP + Sox9 + cells into YFP + hepatic cells, although because of relatively mild hepatotoxicity of CCl4, undamaged hepatocytes also proliferated. Conclusions These results demonstrated that regeneration of chronically damaged liver indeed occurs after anti-fibrosis treatment even under continuous exposure to hepatotoxin, which promises a significant benefit of the anti-fibrosis therapy for refractory liver diseases.

The Ras/RAF/MEK/ERK pathway is an essential signaling cascade for various refractory cancers, such as those with mutant KRAS (mKRAS) and BRAF (mBRAF). However, there are unsolved ambiguities underlying mechanisms for this growth signaling thereby creating therapeutic complications. This study shows that a vital component of the pathway CRAF is directly impacted by an end product of the cascade, glutathione transferases (GST) P1 (GSTP1), driving a previously unrecognized autocrine cycle that sustains proliferation of mKRAS and mBRAF cancer cells, independent of oncogenic stimuli. The CRAF interaction with GSTP1 occurs at its N-terminal regulatory domain, CR1 motif, resulting in its stabilization, enhanced dimerization, and augmented catalytic activity. Consistent with the autocrine cycle scheme, silencing GSTP1 brought about significant suppression of proliferation of mKRAS and mBRAF cells in vitro and suppressed tumorigenesis of the xenografted mKRAS tumor in vivo. GSTP1 knockout mice showed significantly impaired carcinogenesis of mKRAS colon cancer. Consequently, hindering the autocrine loop by targeting CRAF/GSTP1 interactions should provide innovative therapeutic modalities for these cancers.

BACKGROUND:Pulmonary fibrosis is a life-threatening pathological state of progressive interstitial lung diseases, such as idiopathic pulmonary fibrosis. Myofibroblasts are known to play a critical role in the pathogenesis of pulmonary fibrosis. This study aimed to evaluate the inhibitory effect of a small interfering RNA (siRNA) on a collagen-specific chaperone heat shock protein 47 (HSP47). The siRNA was preferentially delivered to myofibroblasts in a bleomycin (BLM)-induced pulmonary fibrosis rat model using siRNA against HSP47, encapsulated in a vitamin A-coupled liposome (VA-lip-siRNA HSP47). METHODS AND RESULTS:Male Sprague-Dawley rats were treated with an intratracheal injection of BLM or phosphate buffered saline followed by an intravenous injection of VA-lip-siRNA HSP47 three times per week under preventive administration schedules from day 1 to day 21 and therapeutic administration schedules from day 15 to day 35. The expression of HSP47 after the treatment was assessed by immunoblotting. The specific delivery of VA-lip-siRNA HSP47 conjugated with 6'-carboxyfluoresce into myofibroblasts was examined by immunofluorescence staining. The effect of VA-lip-siRNA HSP47 on fibrosis was analyzed by morphological and biochemical methods. Preferential delivery of VA-lip-siRNA HSP47 to myofibroblasts in fibrotic areas in BLM-treated rats was verified by immunofluorescence staining. Treatment of VA-lip-siRNA HSP47 clearly suppressed HSP47 expression and induced apoptosis of myofibroblasts in the lung of BLM-treated rats. Hydroxyproline levels and inflammatory cytokines in the lungs, and the number of inflammatory cells in the bronchial alveolar lavage of BLM-treated rats were significantly suppressed by the treatment. Morphological assessment showed that VA-lip-siRNA HSP47 also significantly improved the morphological pulmonary fibrosis of BLM-treated rats in both preventive and therapeutic schedules. CONCLUSIONS:These results suggest that VA-lip-siRNA HSP47 improves pulmonary fibrosis in not only preventive, but also therapeutic schedules, and thus, this drug delivery system should provide a novel therapy for refractory pulmonary fibrosis.

The aim of this dose escalation study was to determine the maximum-tolerated dose (MTD), dose-limiting toxicities (DLTs) and preliminary efficacy of docetaxel, S-1 and cisplatin combination chemotherapy in patients with unresectable metastatic gastric cancer. Seventeen patients received oral S-1 (40 mg m−2 bid) on days 1–14, intravenous cisplatin (60 mg m−2) and docetaxel (60, 70 or 80 mg m−2 depending on DLT) on day 8 every 3 weeks. The MTD of this combination was presumed to be docetaxel 70 mg m−2. At this dose level, 40% of the patients (two of five) developed grade 4 neutropenia and 20% (one of five) exhibited grade 3 nausea during the first course. Therefore, the recommended dose of docetaxel was defined as 60 mg m−2. The DLT was neutropenia. The response rate (RR) was 88.2% (15 of 17), consisting of one complete response and 14 partial responses. There were two stable diseases but no progressive disease. Of these 15 responders, four (23.5%) with high VEGF expression showed rapid tumour regression and achieved downstaging, leading to subsequent curative gastrectomy. Three of these have been disease free for about 3 years, suggesting a complete cure. In conclusion, this regimen was tolerable and showed a quite high RR, with an appreciable downstaging rate in metastatic gastric cancer.

肝硬変は、肝臓において持続的に炎症が引き起こされることで線維化が進行し、病態が進行した場合には、肝臓がんや肝不全等で命を落とす危険性の高い疾患である。近年、抗ウイルス薬の開発が目覚ましい進歩を遂げてきているが、一度線維化が進行した肝臓の線維を積極的に除去する薬ではなく、抗線維症治療薬はアンメット・メディカル・ニーズとして上市が待望されている。筆者らは、HSP47 siRNAを含有するビタミンA修飾リポソーム製剤の開発を進め、2014年より米国にて治験1b/2を開始、現在、日米欧3極で同時に治験を進めているところである。本稿ではこれまでの開発経緯、および他臓器線維症への応用展開について紹介する。

Chronic graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (SCT) is characterized by multiorgan fibrosis and profoundly affects the quality of life of transplant survivors. Heat shock protein 47 (HSP47), a collagen-specific molecular chaperone, plays a critical role in collagen synthesis in myofibroblasts. We explored the role of HSP47 in the fibrotic process of cutaneous chronic GVHD in mice. Immunohistochemical analysis showed massive fibrosis with elevated amounts of collagen deposits and accumulation of F4/80+ macrophages, as well as myofibroblasts expressing HSP47 and retinol-binding protein 1 in the skin after allogeneic SCT. Repeated injection of anti-colony-stimulating factor (CSF-1) receptor-blocking antibodies significantly reduced HSP47+ myofibroblasts in the skin, indicating a macrophage-dependent accumulation of myofibroblasts. Vitamin A-coupled liposomes carrying HSP47 small interfering RNA (siRNA) (VA-lip HSP47) delivered HSP47 siRNA to cells expressing vitamin A receptors and knocked down their HSP47 in vitro. Intravenously injected VA-lip HSP47 were specifically distributed to skin fibrotic lesions and did not affect collagen synthesis in healthy skin. VA-lip HSP47 knocked down HSP47 expression in myofibroblasts and significantly reduced collagen deposition without inducing systemic immunosuppression. It also abrogated fibrosis in the salivary glands. These results highlight a cascade of fibrosis in chronic GVHD; macrophage production of transforming growth factor β mediates fibroblast differentiation to HSP47+ myofibroblasts that produce collagen. VA-lip HSP47 represent a novel strategy to modulate fibrosis in chronic GVHD by targeting HSP47+ myofibroblasts without inducing immunosuppression.

Irinotecan plus S-1 (IRIS) is the only oral fluoropyrimidine-based regimen reported to be non-inferior to FOLFIRI and widely used in clinical practice for metastatic colorectal cancer (mCRC) patients. However, the combination of IRIS plus an anti-EGFR agent has not been evaluated previously. This study aimed to investigate the feasibility and efficacy of IRIS with panitumumab as second-line therapy for wild-type KRAS mCRC.

Background and objectives Mechanism of regeneration of remnant pancreas after partial pancreatectomy (PX) is still unknown. In this study, effect of siRNA against the collagen specific chaperone, HSP47, which inhibits collagen secretion from activated pancreas stellate cells (aPSCs), and induces their apoptosis, on regeneration of remnant pancreas was determined. Methods Pancreatectomy was performed according to established methods. Proliferation of cells was assessed by BrdU incorporation. Immunostaining of HSP47 was employed to identify PSCs. Progenitor cells were identified by SOX9 staining. Acinar cells were immunostained for amylase. Co-culture of acinar cells with aPSCs were carried out in a double chamber with a cell culture insert. siRNA HSP47 encapsulated in vitamin A-coupled liposome (VA-lip siRNA HSP47) was delivered to aPSCs by iv injection. Results In remnant pancreas of 90% PX rat, new areas of foci were located separately from duodenal areas with normal pancreatic features. After PX, BrdU uptake of acinar cells and islet cells significantly increased, but was suppressed by treatment with VA-lip siRNA HSP47. BrdU uptake by acinar cells was augmented by co-culturing with aPSCs and the augmentation was nullified by siRNA HSP47. BrdU uptake by progenitor cells in foci area was slightly enhanced by the same treatment. New area which exhibited intermediate features between those of duodenal and area of foci, emerged after the treatment. Conclusion aPSCs play a crucial role in regeneration of remnant pancreas, proliferation of acinar and islet cells after PX through the activity of secreted collagen. Characterization of new area emerged by siRNA HSP47 treatment as to its origin is a future task.

Transdifferentiation of vitamin A-storing hepatic stellate cells (HSCs) to vitamin A-depleted myofibroblastic cells leads to liver fibrosis. Vitamin A regulates lipid accumulation and gene transcription, suggesting that vitamin A is involved in the maintenance of HSC quiescence under a physiological condition. However, the precise mechanism remains elusive because there is no appropriate in vitro culture system for quiescent HSCs. Here, we show that treatment of quiescent HSCs with vitamin A partially maintained the accumulation of lipid droplets and expression of quiescent HSC markers (glial fibrillary acidic protein, peroxisome proliferator-activator receptor-γ and CCAAT/enhancer-binding protein-α) and also the expression of myofibroblastic markers (α-smooth muscle actin, heat shock protein 47 and collagen type I). On the other hand, combined treatment with vitamin A and insulin sustained the characteristic of HSC quiescence and completely suppressed the expression of myofibroblastic markers through activation of the JAK2/STAT5 signaling pathway and increased expression of sterol regulatory element binding protein-1. These treated HSCs transdifferentiated to myofibroblastic cells under a culture condition with fetal bovine serum. The results suggest an important role of vitamin A and insulin in the maintenance of HSC quiescence under a physiological condition.

732 Background: Panitumumab with fluorouracil, leucovorin, and irinotecan (FOLFIRI) in second-line chemotherapy increased objective response rate and prolonged progression-free survival (PFS) versus FOLFIRI alone in patients with wild-type (WT) KRAS metastatic colorectal cancer (mCRC) (Peeters et al, J Clin Oncol 2010). This trial (UMIN000004659) evaluated tolerability and efficacy of combination therapy with irinotecan and S-1, an oral fluoropyrimidine (IRIS) plus panitumumab as second-line chemotherapy in patients with WT KRASmCRC. Methods: Main inclusion criteria were: patients with WT KRAS mCRC refractory to one prior chemotherapy regimen for mCRC, ECOG PS 0-2, and age ≥20 years. Patients received panitumumab (6 mg/m2) and irinotecan (100 mg/m2) on days 1 and 15 and S-1 (40-60 mg according to body surface area) twice daily for 2 weeks, repeated every 4 weeks. The primary endpoint was completion rate of protocol therapy (CRT). The secondary endpoints were response rate (RR), progression-free survival (PFS), and overall survival (OS). Results: Thirty-seven patients were enrolled in 9 centers. The overall CRT was 62.2% (23/37). Most frequent grade 3/4 toxicities were: skin rash (24%), diarrhea (16%), and appetite loss (11%). The overall RR was 32.4% (12/37). Of these, four patients underwent conversion surgery. Median PFS and OS were 9.5 months (95% CI: 3.5-15.4 months) and 20.1 months (95% CI: 16.7-23.2 months), respectively. Conclusions: IRIS plus panitumumab has acceptable toxicity profile and promising efficacy in patients with previously treated WT KRAS mCRC. This regimen can be an additional treatment option for second-line chemotherapy in WT KRAS mCRC. Clinical trial information: UMIN000004659.