Delayed-onset contact dermatitis caused by olanexidine gluconate antiseptic solution: effect of wiping off the remaining drug solution in two cases.

BACKGROUND: Olanexidine glucuronide (Olanedine®), an antiseptic solution may cause skin dermatitis around one week after disinfection. Although removal after the procedure is recommended to avoid skin dermatitis, whether it is effective for preventing skin dermatitis has not been documented in detail in the literature. CASE PRESENTATION: We encountered two cases of delayed-onset contact dermatitis by Olanedine®. In both cases, the patient's back was disinfected with Olanedine® and was covered with a surgical drape for epidural catheterization. After catheterization and removal of the surgical drape, the insertion site of the catheter was covered with a film dressing, then the epidural catheter was taped to the back. On the third postoperative day, the epidural catheter was removed. On the seventh postoperative day, the patients reported pruritus on the back, where an erythematous papule rash was observed. However, it was not observed at the site covered by the tape to secure the epidural catheter or by the tape of the surgical drape. Symptoms were relieved with oral or topical steroids by the time of discharge. CONCLUSION: Wiping off the remaining Olanedine® even a few days after disinfection may be helpful not only for reducing symptoms but also for preventing the development of contact dermatitis.

Characteristics and outcomes of avoidant/restrictive food intake disorder in Japanese elementary-school students on total parenteral nutrition.

The clinical outcomes of adolescents with avoidant/restrictive food intake disorder (ARFID) remain unclear. Furthermore, no report has compared the characteristics of ARFID and restricting-type anorexia nervosa (R-AN) in elementary-school students on total parenteral nutrition (TPN). This study retrospectively reviewed inpatients diagnosed with ARFID or R-AN between 2005 and 2019. Patients with ARFID (two boys and seven girls) and R-AN (13 girls) were hospitalized because of rapid physical deterioration, and nutrition therapy was continued without withdrawal. The ARFID group exhibited significantly lower body weights at admission than the R-AN group and gained an average of 6.5 kg during hospitalization; furthermore, the monthly weight gain during hospitalization was significantly higher, and no relapse was observed. Early physical improvement in ARFID resulted in good recovery. In conclusion, TPN can be easily introduced to patients with ARFID, in whom aversive eating is a concern, and is a suitable treatment for ARFID.

Erratum: LAMA4 upregulation is associated with high liver metastasis potential and poor survival outcome of Pancreatic Cancer: Erratum.

[This corrects the article DOI: 10.7150/thno.47001.].

PIK3CB is involved in metastasis through the regulation of cell adhesion to collagen I in pancreatic cancer.

Introduction: Pancreatic adenocarcinoma (PAAD) is an aggressive malignancy, with a major mortality resulting from the rapid progression of metastasis. Unfortunately, no effective treatment strategy has been developed for PAAD metastasis to date. Thus, unraveling the mechanisms involved in PAAD metastatic phenotype may facilitate the treatment for PAAD patients. Objectives: PIK3CB is an oncogene implicated in cancer development and progression but less is known about whether PIK3CB participates in PAAD metastasis. Therefore, the objective of this study is to explore the mechanism(s) of PIK3CB in PAAD metastasis. Methods: In our study, we examined the PIK3CB expression pattern using bioinformatic analysis and clinical material derived from patients with PAAD. Subsequently, a series of biochemical experiments were conducted to investigate the role of PIK3CB as potential mechanism(s) underlying PAAD metastasis in vivo using nude mice and in vitro using cell lines. Results: We observed that PIK3CB was involved in PAAD progression. Notably, we identified that PIK3CB was involved in PAAD metastasis. Downregulation of PIK3CB significantly reduced PAAD metastatic potential in vivo. Furthermore, a series of bioinformatic analyses showed that PIK3CB was involved in cell adhesion in PAAD. Notably, PIK3CB depletion inhibited invasion potential specifically via suppressing cell adhesion to collagen I in PAAD cells. Conclusion: Collectively, our findings indicate that PIK3CB is involved in PAAD metastasis through cell-matrix adhesion. We proposed that PIK3CB is a potential therapeutic target for PAAD therapy.

New high-throughput screening detects compounds that suppress pancreatic stellate cell activation and attenuate pancreatic cancer growth.

BACKGROUND/OBJECTIVES: Pancreatic stellate cells (PSCs) are involved in abundant desmoplasia, which promotes cancer cell aggressiveness and resistance to anti-cancer drugs. Therefore, PSCs are suggested to be a promising therapeutic target by attenuating PSC activation to inhibit tumor-stromal interactions with pancreatic cancer cells. Here, we developed a screen to identify compounds that reduce the activity of PSCs and investigated the effect of candidates on pancreatic cancer. METHODS: Lipid droplet accumulation in PSCs was used to observe differences in PSC activity and a new high-throughput screening platform that quantified lipid droplets in PSCs was established. A library of 3398 Food and Drug Administration-approved drugs was screened by this platform. Validation assays were performed in vitro and in vivo. RESULTS: Thirty-two compounds were finally selected as candidate compounds by screening. These compounds decreased α-smooth muscle actin expression and inhibited autophagic flux in PSCs in vitro. Among the candidates, three drugs selected for validation assays inhibited the proliferation and migration of PSCs and invasion of cancer cells by disrupting tumor-stromal interactions. Production of extracellular matrix molecules was also decreased significantly by this treatment. In vivo testing in xenograft models showed that dopamine antagonist zuclopenthixol suppressed tumor growth; this suppression was significantly increased when combined with gemcitabine. CONCLUSIONS: A new screening platform that focused on the morphological features of PSCs was developed. Candidate drugs from this screening suppressed PSC activation and tumor growth. This screening system may be useful to discover new compounds that attenuate PSC activation.

N-acetyl cysteine induces quiescent-like pancreatic stellate cells from an active state and attenuates cancer-stroma interactions.

BACKGROUND: Pancreatic stellate cells (PSCs) occupy the majority of the pancreatic cancer microenvironment, contributing to aggressive behavior of pancreatic cancer cells (PCCs). Recently, anti-fibrotic agents have proven to be an effective strategy against cancer, but clinical trials have shown little efficacy, and the driving mechanism remains unknown. N-acetyl-cysteine (NAC) is often used for pulmonary cystic fibrosis. Pioglitazone, an agonist of peroxisome proliferator-activated receptor gamma, was habitually used for type II diabetes, but recently reported to inhibit metastasis of PCCs. However, few studies have focused on the effects of these two agents on cancer-stromal interactions. METHOD: We evaluated the expression of α-smooth muscle actin (α-SMA) and the number of lipid droplets in PSCs cultured with or without NAC. We also evaluated changes in invasiveness, viability, and oxidative level in PSCs and PCCs after NAC treatment. Using an indirect co-culture system, we investigated changes in viability, invasiveness, and migration of PSCs and PCCs. Combined treatment effects of NAC and Pioglitazone were evaluated in PSCs and PCCs. In vivo, we co-transplanted KPC-derived organoids and PSCs to evaluate the effects of NAC and Pioglitazone's combination therapy on subcutaneous tumor formation and splenic xenografted mouse models. RESULTS: In vitro, NAC inhibited the viability, invasiveness, and migration of PSCs at a low concentration, but not those of PCCs. NAC treatment significantly reduced oxidative stress level and expression of α-SMA, collagen type I in PSCs, which apparently present a quiescent-like state with a high number of lipid droplets. Co-cultured PSCs and PCCs mutually promoted the viability, invasiveness, and migration of each other. However, these promotion effects were attenuated by NAC treatment. Pioglitazone maintained the NAC-induced quiescent-like state of PSCs, which were reactivated by PCC-supernatant, and enhanced chemosensitivity of PCCs. In vivo, NAC and Pioglitazone's combination suppressed tumor growth and liver metastasis with fewer stromal components and oxidative stress level. CONCLUSION: NAC suppressed activated PSCs and attenuated cancer-stromal interactions. NAC induces quiescent-like PSCs that were maintained in this state by pioglitazone treatment.

Candida guilliermondii-induced chorioretinitis in a patient with eating disorder.

Candidemia is a life-threatening fungal infection among patients undergoing long-term intravenous catheterization, hematopoietic stem cell transplantation, or immunosuppressive therapy, as well as patients with severe immunodeficiency or cancer. Endophthalmitis is a rare but severe form of ocular inflammation caused by infection of the intraocular cavity, which can lead to irreversible visual loss if not treated properly and promptly. The initial manifestation typically involves chorioretinitis, which requires early diagnosis and appropriate treatment. Candida guilliermondii is a non-Candida albicans yeast species; its frequency of detection in Japan has increased in recent years, and many drug-resistant and less-chorioretinitis-related strains are known. Here, we describe a 17-year-old girl with an eating disorder who exhibited chorioretinitis because of catheter-related bloodstream infection (CRBSI) caused by C. guilliermondii. The patient was hospitalized with severe weight loss, and she was presumed to develop candidemia because of immunosuppression during central parenteral nutrition therapy with a peripherally inserted central catheter. After onset of CRBSI, the catheter was immediately removed. Antifungal therapy was modified following fundus examination, fungal species confirmation, and drug sensitivity confirmation; thus, the patient recovered without long-term complications. To the best of our knowledge, this is the first report of C. guilliermondii-induced chorioretinitis in a patient with an eating disorder. Prolonged malnutrition and immunosuppression during nutritional therapy create a risk of candidemia in patients with eating disorders. After the onset of CRBSI, early administration and appropriate use of antifungal agents, with respect to specific ocular complications, are important for reduction of both mortality and ocular complications.

Adolescent eating disorder with catheter-related bloodstream infection.

BACKGROUND: Treatment of adolescent eating disorder requires early improvement of nutritional status. Central venous hyperalimentation is used but catheter-related bloodstream infection (CRBSI) is a complication. There have been no reports examining risk factors for CRSBI in eating disorders. METHODS: The subjects were 51 patients who received nutritional therapy with the use of a peripherally inserted central catheter (PICC) from January 2012 to December 2019. The courses of weight and white blood cell (WBC) count were examined retrospectively during nutritional therapy. Onset factors for CRBSI were determined and a case series of CRBSI caused by Candida parapsilosis is presented. RESULTS: The day of minimum weight occurred on or before day 7 in 37 of the 51 patients, and this day was preceded by the day with the lowest WBC at a significant rate. The minimum weight day was significantly delayed in CRSBI cases compared with non-CRBSI cases (P = 0.02). In the case series of CRBSI caused by C. parapsilosis, the median WBC count before CRBSI decreased to 2,570 (1,680-3,270)/µL at a median of day (12-90) 36. Catheter-related bloodstream infection developed at a median of day (26-133) 38. The PICC was immediately removed and an antifungal drug was started, leading to cure with no after effects in all subjects. CONCLUSIONS: In patients with an eating disorder treated with nutritional therapy using a PICC, prolonged resistance to weight gain became a risk factor for developing CRBSI. White blood cell counts recover after weight gain, which suggests that there is a risk of developing CRBSI, even with improved appetite and weight gain.

LAMA4 upregulation is associated with high liver metastasis potential and poor survival outcome of Pancreatic Cancer.

Rationale: Pancreatic cancer is one of the most difficult cancers to manage and its poor prognosis stems from the lack of a reliable early disease biomarker coupled with its highly metastatic potential. Liver metastasis accounts for the high mortality rate in pancreatic cancer. Therefore, a better understanding of the mechanism(s) underlying the acquisition of the metastatic potential in pancreatic cancer is highly desirable. Methods: Microarray analysis in wild-type and highly liver metastatic human pancreatic cancer cell lines was performed to identify gene expression signatures that underlie the metastatic process. We validated our findings in patient samples, nude mice, cell lines and database analysis. Results: We identified a metastasis-related gene, laminin subunit alpha 4 (LAMA4), that was upregulated in highly liver metastatic human pancreatic cancer cell lines. Downregulation of LAMA4 reduced the liver metastatic ability of pancreatic cancer cells in vivo. Furthermore, LAMA4 expression was positively correlated with tumor severity and in silico analyses revealed that LAMA4 was associated with altered tumor microenvironment. In particular, our in vitro and in vivo results showed that LAMA4 expression was highly correlated with cancer-associated fibroblasts (CAFs) level which may contribute to pancreatic cancer metastasis. We further found that LAMA4 had a positive effect on the recruitment and activity of CAFs. Conclusions: These data provide evidence for LAMA4 as a possible biomarker of disease progression and poor prognosis in pancreatic cancer. Our findings indicate that LAMA4 may contribute to pancreatic cancer metastasis via recruitment or activation of CAFs.

Neutrophil extracellular traps promote liver micrometastasis in pancreatic ductal adenocarcinoma via the activation of cancer­associated fibroblasts.

Cancer­associated fibroblasts (CAFs) promote the progression of pancreatic ductal adenocarcinoma (PDAC) via tumor­stromal interactions. Neutrophil extracellular traps (NETs) are extracellular DNA meshworks released from neutrophils together with proteolytic enzymes against foreign pathogens. Emerging studies suggest their contribution to liver metastasis in several types of cancer. Herein, in order to investigate the role of NETs in liver metastasis in PDAC, the effects of NET inhibitors on spontaneous PDAC mouse models were evaluated. It was demonstrated that DNase I, a NET inhibitor, suppressed liver metastasis. For further investigation, further attention was paid to liver micrometastasis and an experimental liver metastasis mouse model was used that was generated by intrasplenic tumor injection. Furthermore, DNase I also suppressed liver micrometastasis and notably, CAFs accumulated in metastatic foci were significantly decreased in number. In vitro experiments revealed that pancreatic cancer cells induced NET formation and consequently NETs enhanced the migration of hepatic stellate cells, which was the possible origin of CAFs in liver metastasis. On the whole, these results suggest that NETs promote liver micrometastasis in PDAC via the activation of CAFs.

Prognostic importance of peritoneal washing cytology in patients with otherwise resectable pancreatic ductal adenocarcinoma who underwent pancreatectomy: A nationwide, cancer registry-based study from the Japan Pancreas Society.

BACKGROUND: The importance of peritoneal washing cytology status both as a sign of irresectability and as a prognostic factor for pancreatic ductal adenocarcinoma remains controversial. The purpose of this nationwide, cancer registry-based study was to clarify the clinical implications of operative resection in patients who had positive cytology status. METHODS: Clinical data from 1,970 patients who underwent tumor resection were collected from the Pancreatic Cancer Registry in Japan. Clinicopathologic factors and overall survival curves were analyzed, and multivariate Cox proportional hazard models were evaluated. RESULTS: Among the 1,970 patients analyzed, positive cytology status was found in 106 patients and negative cytology status was found in 1,864 patients. The positive cytology status group had a greater frequency of pancreatic body and tail cancer and greater preoperative serum carbohydrate antigen 19-9 levels than the negative cytology status group (P < .001 each). The ratio of peritoneal recurrence tended to be greater in the positive cytology status group (14% vs 43%; P < .001). Overall median survival times were less in the positive cytology status group (17.5 months vs 29.4 months; P < .001). The 5-year survival rates were 13.7% and 31.1% in the positive cytology status and negative cytology status groups, respectively. Multivariate analysis of positive cytology status patients revealed that adjuvant chemotherapy was an independent prognostic factor. CONCLUSION: Positive cytology status was an adverse prognostic factor in patients who underwent resection for pancreatic ductal adenocarcinoma but did not preclude attempted curative resection. Curative resection followed by adjuvant chemotherapy may contribute to long-term prognosis in patients with positive cytology status.

S100P regulates the collective invasion of pancreatic cancer cells into the lymphatic endothelial monolayer.

Lymph node metastasis is an independent prognostic factor in pancreatic cancer. However, the mechanisms of lymph node colonization are unknown. As a mechanism of lymphatic metastasis, it has been reported for other types of cancer that spheroids from tumor cells cause circular chemorepellent­induced defects (CCIDs) in lymphatic endothelial monolayers. In pancreatic cancer, such mechanisms of metastasis have not been elucidated. The present study evaluated the involvement of this new mechanism of metastasis in pancreatic cancer and investigated the associated factors. In human pancreatic cancer tissue, it was observed that clusters of cancer cells penetrated the wall of lymphatic ducts around the primary tumor. An in vitro co­culture system was then used to analyze the mechanisms of tumor cell­mediated disruption of lymphatic vessels. Time­lapse microscopic imaging revealed that spheroids from pancreatic cancer cells caused circular defects in lymphatic endothelial monolayers. CCID formation ability differed depending on the cell line. Neither aggregation of spheroids nor adhesion to lymphatic endothelial cells (LECs) exhibited a significant correlation with this phenomenon. The addition of supernatant from cultured cancer cells enhanced CCID formation. Microarray analysis revealed that the expression of S100 calcium binding protein P (S100P) was significantly increased when LECs were treated with supernatant from cultured cancer cells. Addition of a S100P antagonist significantly suppressed the migration of LECs and CCID formation. The present findings demonstrated that spheroids from pancreatic cancer cells caused circular defects in lymphatic endothelial monolayers. These CCIDs in pancreatic cancer were partly regulated by S100P, suggesting that S100P may be a promising target to inhibit lymph node metastasis.

Inhibition of ERK1/2 in cancer-associated pancreatic stellate cells suppresses cancer-stromal interaction and metastasis.

BACKGROUND: Extracellular signal-regulated kinases (ERKs) have been related to multiple cancers, including breast cancer, hepatocellular cancer, lung cancer and colorectal cancer. ERK1/2 inhibitor can suppress growth of KRAS-mutant pancreatic tumors by targeting cancer cell. However, no studies have shown the expression of ERK1/2 on pancreatic stromal and its effect on pancreatic cancer-stromal interaction. METHODS: Immunohistochemistry and western blotting were performed to detect the expression of p-ERK1/2 in pancreatic tissues and cells. Cell viability assay was used to study IC50 of ERK inhibitor on pancreatic cancer cells (PCCs) and primary cancer-associated pancreatic stellate cells (PSCs). Transwell migration, invasion, cell viability assay, senescence ß-galactosidase staining were performed to determine the effect of ERK inhibitor on PCCs and PSCs in vitro and in vivo. The expression of key factors involved in autophagy and epithelial-to-mesenchymal transition (EMT) process were evaluated by western blotting. The expression of key factors related to cell invasiveness and malignancy were confirmed by qRT-PCR. Co-transplantation of PCC Organoid and PSC using a splenic xenograft mouse model was used to evaluated combined treatment of ERK inhibitor and autophagy inhibitor. RESULTS: Immunohistochemical staining in pancreatic tumor samples and transgenetic mice detected p-ERK1/2 expression in both cancer cells and stromal cells. In pancreatic tissues, p-ERK1/2 was strongly expressed in cancer-associated PSCs compared with cancer cells and normal PSCs. PSCs were also significantly more sensitive to ERK1/2 inhibitor treatment. Inhibition of ERK1/2 suppressed EMT transition in HMPCCs, upregulated cellular senescence markers, activated autophagy in cancer-associated PSCs; and suppressed cancer-stromal interaction, which enhanced invasiveness and viability of cancer cells. We also found that chloroquine, an autophagy inhibitor, suppressed ERK inhibition-induced autophagy and promoted PSC cellular senescence, leading to significantly decreased cell proliferation. The combination of an ERK inhibitor and autophagy inhibitor suppressed liver metastasis in a splenic pancreatic cancer organoid xenograft mouse model. CONCLUSIONS: These data indicate that inhibition of ERK1/2 in cancer-associated pancreatic stellate cells suppresses cancer-stromal interaction and metastasis.

CD110 promotes pancreatic cancer progression and its expression is correlated with poor prognosis.

PURPOSE: This study aimed at investigating the function and significance of CD110 expression in pancreatic cancer. METHODS: We performed immunohistochemical staining for CD110 expression in tumor samples from 86 patients with pancreatic cancer. We evaluated clinical outcomes and other clinicopathological factors to determine the significance of CD110 on survival and liver metastasis. We examine thrombopoietin-CD110 signaling in cancer cell extravasation in vitro and in vivo. We investigated the effects of CD110 knockdown on liver metastasis in a splenic xenograft mouse model. RESULTS: CD110 expression in cancer cells was associated with low-histological-grade invasive ductal carcinoma, and patients with high CD110 expression had poorer prognosis (P = 0.0003). High CD110 expression was an independent predictor of liver metastasis (P = 0.0422). Knockdown of CD110 expression significantly attenuated cell migration and invasion. Treatment with thrombopoietin promoted pancreatic cancer cell extravasation. In the presence of thrombopoietin, CD110 increased cell viability through the activation of the ERK-MYC signaling pathway. Knockdown of CD110 expression inhibited liver metastases in the mouse model. CONCLUSIONS: CD110 promotes pancreatic cancer progression and it may serve as a predictive factor for liver metastasis.

Adipose tissue-derived stromal cells are sources of cancer-associated fibroblasts and enhance tumor progression by dense collagen matrix.

Although recent studies revealed that adipose tissue accelerates pancreatic tumor progression with excessive extracellular matrix, key players for desmoplasia in the adipose microenvironment remains unknown. Here, we investigated the roles of adipose tissue-derived stromal cells (ASCs) in desmoplastic lesions and tumor progression by in vitro and in vivo experiments. In a three-dimensional (3-D) organotypic fat invasion model using visceral fat from CAG-EGFP mice, GFP-positive fibroblastic cells infiltrated toward cancer cells. When tumor cells were inoculated into transplanted visceral fat pads in vivo, tumor weights and stromal components were enhanced compared to subcutaneous and orthotopic tumor cells inoculated without fat pads. Expression of αSMA in established human ASCs was lower compared to cancer associated fibroblasts, and the 3-D collagen matrices produced by ASCs cultured in cancer cell-conditioned medium changed from loose to dense structures that affected the motility of cancer cells. Microarray analyses revealed upregulation of S100A4 in ASCs, while S100A4-positive stromal cells were observed at extrapancreatic invasion sites of human pancreatic cancer. The present findings indicate that ASCs are recruited to extrapancreatic invasion sites and produce dense collagen matrices that lead to enhanced tumor progression. Both inhibition of ASCs recruitment and activation could lead to a novel antistromal therapy.

Cancer-associated acinar-to-ductal metaplasia within the invasive front of pancreatic cancer contributes to local invasion.

The pancreas is an organ prone to inflammation, fibrosis, and atrophy because of an abundance of acinar cells that produce digestive enzymes. A characteristic of pancreatic cancer is the presence of desmoplasia, inflammatory cell infiltration, and cancer-associated acinar atrophy (CAA) within the invasive front. CAA is characterized by a high frequency of small ducts and resembles acinar-to-ductal metaplasia (ADM). However, the clinical significance of changes in acinar morphology, such as ADM with acinar atrophy, within the tumor microenvironment remains unclear. Here, we find that ADM within the invasive front of tumors is associated with cell invasion and desmoplasia in an orthotopic mouse model of pancreatic cancer. An analysis of resected human tumors revealed that regions of cancer-associated ADM were positive for TGFα, and that this TGFα expression was associated with primary tumor size and shorter survival times. Gene expression analysis identified distinct phenotypic profiles for cancer-associated ADM, sporadic ADM and chronic pancreatitis ADM. These findings suggest that the mechanisms driving ADM differ according to the specific tissue microenvironment and that cancer-associated ADM and acinar atrophy contribute to tumor cell invasion of the local pancreatic parenchyma.

Visualizing Energy Charge in Breast Carcinoma Tissues by MALDI Mass-spectrometry Imaging Profiles of Low-molecular-weight Metabolites.

BACKGROUND/AIM: Metabolomics is widely used for biomarker discovery, but conventional mass-spectrometry extraction procedures lose the spatial localization of metabolites. In this study, we directly analyzed breast carcinoma tissues embedded in frozen tissue microarrays (fTMAs) using MALDI mass-spectrometry imaging (MALDI-MSI). MATERIALS AND METHODS: A total of 119 breast tissues (84 carcinoma and 35 normal) were used. MSI data were extracted from each tissue. RESULTS: Overall, 185 of 1,915 peaks which were commonly detected in 60% of target areas were subjected to further analysis. One hundred and fifty-two peaks of carcinoma showed significantly higher intensity than normal. Comparing metabolite profiles from carcinoma and normal tissues, energy charge (EC) and the sum of adenosine phosphate compound (AXP) indicated significantly higher intensities in cancerous tissues than normal. But comparisons of EC and AXP among lymph node metastasis, tumor size and tumor subtypes indicated no significant differences. CONCLUSION: Breast carcinoma tissues had higher EC and AXP values than normal. MALDI-MSI could be a tool for characterizing breast carcinoma.

Basement membrane destruction by pancreatic stellate cells leads to local invasion in pancreatic ductal adenocarcinoma.

Stroma invasion is an important step in pancreatic cancer progression. However, how pancreatic ductal adenocarcinoma (PDAC) with ductal structure invades the surrounding stroma has not been clear. Here, we elucidated the mechanism of stromal invasion of PDAC, using organoids. From resected PDAC specimens, we established human PDAC organoids, which developed ductal and basement membrane (BM) structures. When the organoids were co-cultured with pancreatic stellate cells (PSCs) in a collagen matrix, organoids lost their BM and ductal structures, and invaded collagen matrix more frequently than did mono-cultured organoids. Interestingly, direct contact by PSCs to PDAC organoids was observed before BM destruction. Matrix metalloproteinase (MMP) 2 or membrane type-1 MMP (MT1MMP) knockdown in PSCs significantly attenuated BM destruction by PSCs, and retained the ductal structures in organoids. Our results imply that direct contact by PSCs induces BM destruction and stromal invasion of PDAC via MMP2 which binds to MT1MMP on PSCs.

Pancreatic stellate cells reorganize matrix components and lead pancreatic cancer invasion via the function of Endo180.

Specific cell populations leading the local invasion of cancer are called "leading cells". However, the underlying mechanisms are unclear. Here, we identified leading cells in pancreatic cancer and determined how these cells lead and promote cancer cell invasion in the extracellular matrix (ECM). Using three-dimensional matrix remodeling assay, we found that pancreatic stellate cells (PSCs) frequently invaded the collagen matrix with pancreatic cancer cells (PCCs), which invaded behind the invading PSCs. In addition, invading PSCs changed the alignment of collagen fibers, resulting in ECM remodeling and an increase in the parallel fibers along the direction of invading PSCs. Endo180 expression was higher in PSCs than in PCCs, Endo180 knockdown in PSCs attenuated the invasive abilities of PSCs and co-cultured PCCs, and decreased the expression level of phosphorylated myosin light chain 2 (MLC2). In mouse models, Endo180-knockdown PSCs suppressed tumor growth and changes in collagen fiber orientation in co-transplantation with PCCs. Our findings suggest that PSCs lead the local invasion of PCCs by physically remodeling the ECM, possibly via the function of Endo180, which reconstructs the actin cell skeleton by phosphorylation of MLC2.

Autophagy inhibition enhances antiproliferative effect of salinomycin in pancreatic cancer cells.

BACKGROUND: Salinomycin has cytotoxic effects on various types of malignancy and induces autophagy. However, it has not been clarified whether autophagy induced by salinomycin treatment has a protective or cytotoxic role. We investigated whether salinomycin affects autophagy in pancreatic cancer cells and whether autophagy induced by salinomycin treatment has a protective or cytotoxic role in these cells. METHODS: We investigated the effect of salinomycin using three pancreatic cancer cell lines. We investigated effect on proliferation and the CD133 positive fraction using flow cytometry. In addition, we monitored the change in autophagic activity after salinomycin treatment using fluorescent immunostaining, western blotting, and flow cytometry. Finally, knockdown of ATG5 or ATG7 by siRNA was used to investigate the impact of autophagy inhibition on sensitivity to salinomycin. RESULTS: Salinomycin suppressed the proliferation of pancreatic cancer cells in a concentration dependent manner, and reduced the CD133 positive fraction. Salinomycin enhanced autophagy activity in these cells in a concentration dependent manner. Autophagy inhibition made pancreatic cancer cells more sensitive to salinomycin. CONCLUSIONS: Our data provide the first evidence indicating that autophagy induced by salinomycin have a protective role in pancreatic cancer cells. A new therapeutic strategy of combining salinomycin, autophagy inhibitors, and anticancer drugs could hold promise for pancreatic cancer treatment.