Involvement of Glycogen Synthase Kinase 3ß (GSK3ß) in Formation of Phosphorylated Tau and Death of Retinal Ganglion Cells of Rats Caused by Optic Nerve Crush.

Tauopathy is a neurodegenerative condition associated with oligomeric tau formation through abnormal phosphorylation. We previously showed that tauopathy is involved in death of retinal ganglion cells (RGCs) after optic nerve crush (ONC). It has been proposed that glycogen synthase kinase 3ß (GSK3ß) is involved in the hyperphosphorylation of tau in Alzheimer's disease. To determine the roles of GSK3ß in tauopathy-related death of RGCs, lithium chloride (LiCl), a GSK3ß inhibitor, was injected intravitreally just after ONC. The neuroprotective effects of LiCl were determined by counting Tuj-1-stained RGCs on day 7. Changes of phosphorylated (ser 396) tau in the retina were determined by Simple Western analysis (WES) on day 3. Retinal GSK3ß levels were determined by immunohistochemistry (IHC) and an ELISA. There was a 1.9- and 2.1-fold increase in the levels of phosphorylated tau monomers and dimers on day 3 after ONC. LiCl significantly suppressed the increase in the levels of phosphorylated tau induced by ONC. GSK3ß was mainly present in somas of RGCs, and ELISA showed that retinal levels increased to 2.0-fold on day 7. IHC showed that the GSK3ß expression increased over time and remained in RGCs that were poorly stained by Tuj-1. The GSK3ß and tau expression was colocalized in RGCs. The number of RGCs decreased from 1881 ± 188 (sham control) to 1150 ± 192 cells/mm2 on day 7, and LiCl preserved the levels at 1548 ± 173 cells/mm2. Accordingly, GSK3ß may be a promising target for some optic nerve injuries.

Solo surgery in robot-assisted gastrectomy versus laparoscopic gastrectomy for gastric cancer: a propensity score-matched analysis.

BACKGROUND: Robot-assisted gastrectomy (RG) for gastric cancer is still not well standardized. This study aimed to explore the feasibility and effectiveness of solo surgery in robot-assisted gastrectomy (SRG) for gastric cancer compared to laparoscopic gastrectomy (LG). METHODS: This was a single-center retrospective comparative study between SRG and conventional LG. Between April 2015 and December 2022, 510 patients underwent gastrectomy, and data from a prospectively collected database were analyzed. We identified 372 patients who underwent LG (n = 267) and SRG (n = 105) and the remaining 138 patients were excluded because of remnant gastric cancer, esophagogastric junction cancer, open gastrectomy, concurrent surgery for concomitant malignancies, RG before starting SRG, or cases in which the author was unable to perform or supervise gastrectomy. Propensity score matching was performed at a ratio of 1:1 to reduce bias from confounding patient-related variables, and short-term outcomes were compared between the groups. RESULTS: After propensity score matching, 90 pairs of patients who underwent LG and SRG were selected. In the propensity-matched cohort, the operation time was significantly shorter in the SRG group than that in the LG group (SRG = 305.7 ± 74.0 min vs. LG = 340.3 ± 91.65 min, p < 0.0058), less estimated blood loss was observed in the SRG group than that in the LG group (SRG = 25.6 ± 50.6 mL vs. LG = 76.1 ± 104.2 mL, p < 0.0001) and postoperative hospital stay was shorter in the SRG group than that in the LG group (SRG = 7.1 ± 0.8 days vs. LG = 9.1 ± 7.7 days, p = 0.015). CONCLUSION: We found that SRG for gastric cancer was technically feasible and effective with favorable short-term outcomes, including shorter operative time, less estimated blood loss, shorter hospital stays, and lower postoperative morbidity than those in LG.

The expression of carcinoembryonic antigen mRNA in the lavage of the dissected area of the lateral lymph nodes influences the lateral recurrence of lower rectal cancer.

PURPOSE: To determine whether or not migrating cancer cells are present on the surgical plane after lateral lymph node dissection (LLND) for lower rectal cancer and related to lateral recurrence (LR), we evaluated the lavage of LLND areas by reverse-transcription polymerase chain reaction (RT-PCR) to check the expression of CEA mRNA in the residual cancer cells. METHODS: Thirty patients who underwent curative LLND were enrolled. Lavage was collected after LLND and subjected to RT-PCR to detect CEA mRNA. The median follow-up to check for recurrence was 31.4 months. RESULTS: CEA mRNA was detected in 9 of the 46 dissected areas. Based on the receiver operating characteristic curves, the cut-off value of PCR was set at 0.025. This cut-off point classified five patients into the high-expression group for CEA mRNA. During follow-up, LR developed in 1 of 40 low-expression areas of CEA mRNA and 3 of 6 high-expression areas. The LR rate was higher in the high-expression group than in the low-expression group (p = 0.015). A multivariate analysis showed that the high expression of CEA mRNA was likely an independent prognostic factor of LR. CONCLUSION: The expression of CEA mRNA in the lavage of LLND areas indicates the presence of residual cancer cells that cause LR.

Efficacy of intraoperative ICG fluorescence imaging evaluation for preventing anastomotic leakage after left-sided colon or rectal cancer surgery: a propensity score-matched analysis.

BACKGROUND: Intestinal perfusion at the anastomotic site is thought to be one of the most influential risk factors for postoperative anastomotic leakage (AL). We evaluated the efficacy of indocyanine green (ICG) fluorescence imaging at the stump of the proximal colon in left-sided colectomy or rectal resection in terms of decreasing the incidence of AL. METHODS: Prospectively collected data were retrospectively evaluated. Patients who underwent left-sided colectomy or rectal resection were enrolled (ICG group; n = 197), and patients who had undergone a similar procedure before the ICG group were enrolled from the charts as historical controls (HC group; n = 187). After ICG evaluation, anastomosis was performed where fluorescence was sufficient. The incidence of AL was compared between the ICG and HC groups. Propensity score (PS)-matched data were analyzed to clarify the risk of AL. RESULTS: AL occurred in 6 patients (3.3%) in the ICG group and 17 (10.7%) in the HC group. ICG evaluation revealed 179 patients with good fluorescence and 18 with poor/none perfusion (9.1%). The transection line was changed in all patients with poor/none fluorescence. Three of these 18 patients developed AL (16.7%), though transection line was changed at which is thought to be good. We hope AL in poor/none fluorescence can be prevented at the same rate of cases with good fluorescence. Actually, the rate of that was significantly higher compared with good fluorescence patients (P = 0.038). 93 patients in each group were compared by PS-matched data analysis, which showed the AL rate in the ICG group was significantly lower than that in the HC group (3.2% vs 10.8%, respectively; P = 0.046). CONCLUSIONS: Even though this study has limitations of comparison of data prospectively collected and retrospectively analyzed, intraoperative ICG fluorescence imaging evaluation could significantly decrease the incidence of AL.

Roscovitine, a Cyclin-Dependent Kinase-5 Inhibitor, Decreases Phosphorylated Tau Formation and Death of Retinal Ganglion Cells of Rats after Optic Nerve Crush.

Tauopathies are neurodegenerative diseases characterized by abnormal metabolism of misfolded tau proteins and are progressive. Pathological phosphorylation of tau occurs in the retinal ganglion cells (RGCs) after optic nerve injuries. Cyclin-dependent kinase-5 (Cdk5) causes hyperphosphorylation of tau. To determine the roles played by Cdk5 in retinal degeneration, roscovitine, a Cdk5 inhibitor, was injected intravitreally after optic nerve crush (ONC). The neuroprotective effect of roscovitine was determined by the number of Tuj-1-stained RGCs on day 7. The change in the levels of phosphorylated tau, calpain-1, and cleaved α-fodrin was determined by immunoblots on day 3. The expression of P35/P25, a Cdk5 activator, in the RGCs was determined by immunohistochemistry. The results showed that roscovitine reduced the level of phosphorylated tau by 3.5- to 1.6-fold. Calpain-1 (2.1-fold) and cleaved α-fodrin (1.5-fold) were increased on day 3, suggesting that the calpain signaling pathway was activated. P35/P25 was accumulated in the RGCs that were poorly stained by Tuj-1. Calpain inhibition also reduced the increase in phosphorylated tau. The number of RGCs decreased from 2191 ± 178 (sham) to 1216 ± 122 cells/mm2 on day 7, and roscovitine preserved the level at 1622 ± 130 cells/mm2. We conclude that the calpain-mediated activation of Cdk5 is associated with the pathologic phosphorylation of tau.

Accurate localization of rectal cancer using near infrared ray-guided surgery with intra-operative colonoscopy and da Vinci Firefly technology.

Accurate localization of the tumor during robot-assisted laparoscopic surgery for rectal cancer is crucial. Several techniques have been described, but each has its shortcomings. We developed a new technique of near infrared ray-guided surgery (NIRGS) to localize the tumor accurately, using intra-operative colonoscopy and da Vinci Firefly technology. After clamping the oral side of the tumor, the colonoscope was inserted. In the normal visible light mode, we could not recognize the endoscopic light; however, after changing to the Firefly mode, the endoscopic light was seen clearly. Using this simple and new technique, we could locate the tumor easily and accurately. We performed this technique in 12 patients and detected the location of the tumor clearly in all, without any procedure-related complications. Based on these findings, NIRGS is a useful and safe technique for detecting tumor location during robot-assisted laparoscopic surgery for rectal cancer.

Laparoscopic extraperitoneal sigmoid colostomy using the totally extraperitoneal hernia repair technique after abdominoperineal resection for rectal cancer.

Stoma creation through the extraperitoneal route reportedly reduces the risk of parastomal hernia and stomal prolapse after abdominoperineal resection (APR) for rectal cancer. We describe a new technique for laparoscopic extraperitoneal sigmoid colostomy following APR. After the rectus abdominis muscle is separated, Lap ProtectorTM and EZ AccessTM devices are placed. An extraperitoneal stoma tunnel is created laparoscopically as much as possible. Next, the peritoneum is separated from the inside of the abdominal cavity, and the extraperitoneal tunnel is opened. At the time of writing, we had performed laparoscopic extraperitoneal sigmoid colostomy in eight patients, without any complications or conversion to the conventional procedure. Thus, laparoscopic extraperitoneal sigmoid colostomy is a useful and safe technique for the laparoscopic creation of an extraperitoneal stoma tunnel after APR.

No inflammatory benefit obtained by single-incision laparoscopic surgery for right hemicolectomy compared with conventional laparoscopy.

PURPOSE: We evaluated the perioperative inflammatory mediators in a right hemicolectomy performed with single-incision laparoscopic surgery (SILS) and traditional multi-port laparoscopic surgery (MLS) to compare the postoperative inflammatory response and feasibility of SILS with that of MLS. METHODS: In this retrospective study, we enrolled 56 consecutive colorectal cancer patients who underwent right hemicolectomy prospectively. Twenty patients underwent SILS, and 36 underwent MLS. The preoperative and postoperative levels of plasma vascular endothelial growth factor (VEGF), serum interleukin-6 (IL-6), and C-reactive protein (CRP) as well as the number of platelet cells were measured in all patients. The operation duration, number of harvested lymph nodes, length of the resected bowel, blood loss, and duration of hospital stay were also compared between the two groups. RESULTS: Neither SILS nor MLS had any conversion cases. The operation duration was longer for MLS than for SILS. Blood loss tended to be lower among patients who underwent SILS than among those who underwent MLS. However, the number of harvested LNs was significantly lower with SILS than with MLS. In both pre- and postoperative blood examinations, there was no marked difference in inflammatory mediators between MLS and SILS. CONCLUSION: There was no systemic inflammatory advantage associated with SILS compared with MLS.

[Review of High-Risk Factors and Adjuvant Chemotherapy Indication in T4-pStage â ¡ Colon Cancer].

BACKGROUND: T4 is one of the high-risk factors, but the efficacy of adjuvant chemotherapy for T4-Stage Ⅱ colon cancer are unclear. METHOD: We retrospectively reviewed 211 patients with primary pStage Ⅱ colon cancer who underwent radical resection between 2004 and 2015. RESULTS: The 5-year overall survival rate(OS)of Stage ⅡA/ⅡB/ⅡC were 90.2/83.4/ 59.2%, and the 5-year recurrence-free survival rate(RFS)were 87.3/73.3/42.8%. Multivariate analysis of OS as a high-risk factor of T4 revealed male, ly2/3, no adjuvant chemotherapy, and in RFS, male, ly2/3. However, compared the cases with or without adjuvant chemotherapy, 5-year OS was no difference. There were no cases used oxaliplatin-based adjuvant chemotherapy. CONCLUSION: An adjuvant chemotherapy without oxaliplatin were not enough to improve the prognoses of T4-Stage Ⅱcolon cancer, so the oxaliplatin based regimen might be recommended.

Inflammatory pseudotumor of the liver diagnosed as metastatic liver tumor in a patient with a gastrointestinal stromal tumor of the rectum: report of a case.

BACKGROUND: Inflammatory pseudotumor (IPT) of the liver is a rare benign lesion. A case of IPT of the liver found in association with a malignant gastrointestinal stromal tumor (GIST) is reported. CASE REPORT: A 74-year-old man was admitted to our hospital for a liver tumor. He previously underwent rectal amputation for a malignant GIST. Computed tomography (CT) revealed a low-density area in the liver and dynamic contrast-enhanced MRI (EOB-MRI) showed that the tumor was completely washed out in the delayed phase. 18Fluorine-fluorodeoxyglucose positron emission tomography (FDG-PET) showed strong uptake in the liver. A diagnosis of liver metastasis was made and partial hepatectomy was performed. Microscopic examination showed that the tumor was an IPT. CONCLUSION: Differential diagnosis between IPT and malignant neoplasms is difficult. Moreover, FDG-PET revealed strong uptake in the tumor. To our knowledge, this is the first patient reported to have an IPT in association with a rectal GIST. This patient is discussed along with a review of the literature.

Mitotic phosphorylation of MPP8 by cyclin-dependent kinases regulates chromatin dissociation.

Repressive epigenetic modifications, DNA methylation at CpG sites and histone H3 lysine 9 (H3K9) methylation, are enriched in heterochromatin, which undergoes drastic changes in structure during mitosis. MPP8 (M phase phosphoprotein 8) has been proposed to regulate positive association between these two repressive modifications, but actual involvement of this protein in changes in the heterochromatin structure during mitosis remains elusive. We demonstrate here that MPP8 predominantly localized to, but dissociated from, chromatin during interphase and early mitosis, respectively. Chromatin dissociation from MPP8 appeared to correlate with the phosphorylation status of MPP8. Experiments using inhibitors of various mitotic kinases demonstrated that the chromatin dissociation of MPP8 during metaphase to anaphase was specifically regulated by cyclin B1-Cdk1. Indeed, cyclin B1-Cdk1 effectively phosphorylated MPP8 in vitro and on STA mutant of MPP8 (all possible sites phosphorylated by Cdk were substituted by alanine) failed to dissociate from chromatin during early mitosis. Taken together, our results indicate that the chromatin association of MPP8 is regulated by Cdk-dependent phosphorylation.

Elevated Preoperative Serum Vascular Endothelial Growth Factor Does Not Predict Poor Outcomes in Curatively Resected Non-metastatic Colorectal Cancer Treated Without Neoadjuvant Therapy.

BACKGROUND/AIM: Vascular endothelial growth factor (VEGF) influences colorectal cancer (CRC) progression and is a key target in the treatment for metastatic CRC. However, the oncological impact of preoperative circulating VEGF in non-metastatic CRC (non-mCRC) has not been clearly elucidated. Herein, we have investigated the prognostic significance of elevated preoperative serum VEGF concentration in curatively resected non-mCRC without neoadjuvant therapy. PATIENTS AND METHODS: A total of 474 patients with pStage I-III CRC who underwent curative resection without neoadjuvant therapy were included. The relationship between preoperative serum VEGF concentration and clinicopathologic characteristics, overall survival (OS), and recurrence-free survival (RFS) were investigated. RESULTS: The median follow-up duration was 47.4 months. No significant relationship between preoperative VEGF and clinicopathologic characteristics including tumor markers, pStage, and lymphovascular invasion was identified; however, VEGF values were wide-ranged in every pStage. Patients were categorized into four groups as follows: VEGF < median, median to 75th percentile, 75th percentile to 90th percentile, and ≥90th percentile. A tendency for a difference in 5-year OS (p=0.064) and RFS (p=0.089) was observed among the groups; however, OS and RFS were not correlated with VEGF elevation. In multivariate analyses, VEGF ≥90th percentile was paradoxically associated with better RFS. CONCLUSION: Preoperative elevated serum VEGF concentration was associated with neither worse clinicopathological characteristics nor worse long-term outcomes in curatively resected non-mCRC. The prognostic value of preoperative circulating VEGF in initially resectable non-mCRC remains limited.

AZD6738 promotes the tumor suppressive effects of trifluridine in colorectal cancer cells.

Ataxia telangiectasia and Rad3­related (ATR) is a kinase that repairs DNA damage. Although inhibitors that selectively target ATR have been developed, their effectiveness in colorectal cancer has not been widely reported. The present study hypothesized that anticancer agents that effectively act in the S phase before the G2/M checkpoint may be ideal agents for concomitant use with ATR inhibitors, which act at the G2/M checkpoint. Therefore, the present study examined the combined effects of AZD6738, an ATR inhibitor, and trifluridine (FTD), which acts in the S phase and has a high DNA uptake rate. In vitro cell viability assays, flow cytometry and western blotting were performed to evaluate cell viability, and changes in cell cycle localization and protein expression. The results revealed that in colorectal cancer cells, the combination of AZD6738 and FTD inhibited cell viability, cell cycle arrest at the G2/M checkpoint and Chk1 phosphorylation, and increased apoptotic protein expression levels more than that when treated with FTD alone. HT29, a BRAF­mutant cell line known to be resistant to anticancer drugs, was used to induce tumors in vivo. Since FTD does not have sufficient efficacy when administered orally, it was mixed with tipiracil to prevent degradation; this mixture is known as TAS­102. TAS­102 alone exerted minimal tumor suppressive effects; however, when used in combination with AZD6738, tumor suppression was observed, suggesting that AZD6738 may increase the effectiveness of a weakly effective drug. Although ATR inhibitors are effective against p53 mutants, the present study demonstrated that these inhibitors were also effective against the p53 wild­type HCT116 colorectal cancer cell line. In conclusion, combination therapy with AZD6738 and FTD enhanced the inhibition of tumor proliferation in vitro and in vivo. In the future, we aim to investigate the potentiating effect of AZD6738 on 5­fluouracil­resistant cell lines that are difficult to treat.

Cancer cell­induced tissue inhibitor of metalloproteinase­1 secretion by cancer­associated fibroblasts promotes cancer cell migration.

Cancer­associated fibroblasts (CAFs) are one of the major components of the cancer stroma in the tumor microenvironment. The interaction between cancer cells and CAFs (cancer­stromal interaction; CSI) promotes tumor progression, including metastasis. Recently, the tissue inhibitor of metalloproteinase­1 (TIMP­1) was reported to promote cancer cell migration and metastasis, which is contrary to its anticancer role as an inhibitor of matrix metalloproteinase. Moreover, CAF­derived TIMP­1 is reported to regulate CAF activity. In the present study, we investigated the effect of TIMP­1 on colon cancer cell migration in vitro. The TIMP­1 secretion levels from the CAFs and cancer cell lines were comparatively measured to determine the main source of TIMP­1. Furthermore, the effect of CSI on TIMP­1 secretion was investigated using the Transwell co­culture system. Cancer cell migration was evaluated using the wound­healing assay. The results demonstrated that TIMP­1 promoted the migration of LoVo cells, a colon cancer cell line, whereas TIMP­1 neutralization inhibited the enhanced migration. The TIMP­1 levels secreted from the cancer cells were approximately 10 times less than those secreted from the CAFs. TIMP­1 secretion was higher in CAFs co­cultured with cancer cells than in monocultured CAFs. Furthermore, the migration of LoVo cells increased upon co­culturing with the CAFs. TIMP­1 neutralization partially inhibited this enhanced migration. These results suggest that CAFs are the primary source of TIMP­1 and that the TIMP­1 production is enhanced through CSI in the tumor microenvironment, which promotes cancer cell migration.

The Interaction Between Cancer-associated Fibroblasts and Cancer Cells Enhances Bcl-xL and Mcl-1 in Colorectal Cancer.

BACKGROUND/AIM: The acquisition of resistance to apoptosis is one of the biggest problems in colorectal cancer (CRC) treatment. This study aimed to elucidate the mechanisms of resistance to apoptosis with a focus on interleukin (IL)-6 produced by the interaction between cancer cells and cancer-associated fibroblasts (CAFs). MATERIALS AND METHODS: DLD-1 and HCT116 cell lines were treated with IL-6 and furthermore co-cultured with CAFs. The expression levels of Bcl-xL, Mcl-1 and phosphorylation of STAT3 were evaluated by western blotting. We also performed immunostaining for CRC specimens and evaluated the correlation between CAFs invasion and Bcl-xL/Mcl-1 expression. RESULTS: Both IL-6 and co-culturing enhanced Bcl-xL, Mcl-1 and the phosphorylation of STAT3. Immunohistochemistry showed a positive correlation between CAFs and Bcl-xL/Mcl-1. These results showed that the interaction between CAFs and cancer cells enhances Bcl-xL and Mcl-1 through the IL-6/STAT3 signaling pathway. CONCLUSION: Our findings provide new potential therapeutic targets and strategies for CRC treatment.

ATR inhibitor AZD6738 increases the sensitivity of colorectal cancer cells to 5­fluorouracil by inhibiting repair of DNA damage.

The repair of DNA damage caused by chemotherapy in cancer cells occurs mainly at two cell cycle checkpoints (G1 and G2) and is a factor contributing to chemoresistance. Most colorectal cancers harbor mutations in p53, the main pathway involved in the G1 checkpoint, and thus, are particularly dependent on the G2 checkpoint for DNA repair. The present study examined the effect of AZD6738, a specific inhibitor of ataxia telangiectasia mutated and rad3­related (ATR) involved in the G2 checkpoint, combined with 5­fluorouracil (5­FU), a central chemotherapeutic agent, on colorectal cancer cells. Since 5­FU has a DNA­damaging effect, its combination with AZD6738 is likely to enhance the therapeutic effect. The effects of the AZD6738/5­FU combination were evaluated in various colorectal cancer cells (HT29, SW480, HCT116 and DLD­1 cells) by flow cytometry (HT29 cells), western blotting (HT29 cells) and water­soluble tetrazolium 1 assays (HT29, SW480, HCT116 and DLD­1 cells), as well as in an experimental animal model (HT29 cells). In vitro, the AZD6738/5­FU combination increased the number of mitotic cells according to flow cytometry, decreased the checkpoint kinase 1 phosphorylation levels and increased cleaved caspase­3 and phosphorylated form of H2A.X variant histone levels according to western blotting, and decreased the proliferation rate of four colon cancer cell lines according to cell viability experiments. In vivo, xenografted colorectal cancer cells treated with the AZD6738/5­FU combination exhibited a marked decrease in proliferation compared with the 5­FU alone group. The present results suggested that AZD6738 enhanced the effect of 5­FU in p53­mutated colorectal cancer.

The clinical impact of robot-assisted laparoscopic rectal cancer surgery associated with robot-assisted radical prostatectomy.

INTRODUCTION: Robot-assisted laparoscopic surgery has been performed in various fields, especially in the pelvic cavity. However, little is known about the utility of robot-assisted laparoscopic rectal cancer surgery associated with robot-assisted radical prostatectomy (RARP). We herein report the clinical impact of robot-assisted laparoscopic rectal cancer surgery associated with RARP. METHODS: We experienced five cases of robot-assisted laparoscopic rectal cancer surgery associated with RARP. One involved robot-assisted laparoscopic abdominoperineal resection with en bloc prostatectomy for T4b rectal cancer, and one involved robot-assisted laparoscopic intersphincteric resection combined with RARP for synchronous rectal and prostate cancer. The remaining three involved robot-assisted laparoscopic low anterior resection (RaLAR) after RARP. For robot-assisted laparoscopic rectal cancer surgery, the da Vinci Xi surgical system was used. RESULTS: We could perform planned robotic rectal cancer surgery in all cases. The median operation time was 529 min (373-793 min), and the median blood loss was 307 ml (32-1191 ml). No patients required any transfusion in the intra-operative or immediate peri-operative period. The circumferential resection margin was negative in all cases. There were no complications of grade ≥III according to the Clavien-Dindo classification and no conversions to conventional laparoscopic or open surgery. CONCLUSION: Robot-assisted laparoscopic surgery associated with RARP is feasible in patients with rectal cancer. The long-term surgical outcomes remain to be further evaluated.

Chitinase 3-like 1 secreted from cancer-associated fibroblasts promotes tumor angiogenesis via interleukin-8 secretion in colorectal cancer.

The cancer­stromal interaction has been demonstrated to promote tumor progression, and cancer-associated fibroblasts (CAFs), which are the main components of stromal cells, have attracted attention as novel treatment targets. Chitinase 3-like 1 (CHI3L1) is a chitinase-like protein, which affects cell proliferation and angiogenesis. However, the mechanisms through which cells secrete CHI3L1 and through which CHI3L1 mediates tumor progression in the cancer microenvironment are still unclear. Accordingly, the present study assessed the secretion of CHI3L1 in the microenvironment of colorectal cancer and evaluated how CHI3L1 affects tumor angiogenesis. CAFs and normal fibroblasts (NFs) established from colorectal cancer tissue, and human colon cancer cell lines were evaluated using immunostaining, cytokine antibody array, RNA interference, reverse transcription-quantitative PCR (RT-qPCR), ELISA, western blotting and angiogenesis assays. The expression and secretion of CHI3L1 in CAFs were stronger than those in NFs and colorectal cancer cell lines. In addition, interleukin-13 receptor α2 (IL-13Rα2), a receptor for CHI3L1, was not expressed in colorectal cancer cell lines, but was expressed in fibroblasts, particularly CAFs. Furthermore, the expression and secretion of IL-8 in CAFs was stronger than that in NFs and cancer cell lines, and recombinant CHI3L1 addition increased IL-8 expression in CAFs, whereas knockdown of CHI3L1 suppressed IL-8 expression. Furthermore, IL-13Rα2 knockdown suppressed the enhancement of IL-8 expression induced by CHI3L1 treatment in CAFs. For vascular endothelial growth factor-A (VEGFA), similar results to IL-8 were observed in an ELISA for comparison of secretion between CAFs and NFs and for changes in secretion after CHI3L1 treatment in CAFs; however, no significant differences were observed for changes in expression after CHI3L1 treatment or IL-13Rα2 knockdown in CAFs assessed using RT-qPCR assays. Angiogenesis assays revealed that tube formation in vascular endothelial cells was suppressed by conditioned medium from CAFs with the addition of human CHI3L1 neutralizing antibodies compared with control IgG, and also suppressed by conditioned medium from CAFs transfected with CHI3L1, IL-8 or VEGFA small interfering RNA compared with negative control small interfering RNA. Overall, the present findings indicated that CHI3L1 secreted from CAFs acted on CAFs to increase the secretion of IL-8, thereby affecting tumor angiogenesis in colorectal cancer.

A Case of Presumed Dyskeratosis Congenita Causing Severe Retinal Vascular Occlusion.

Dyskeratosis congenita (DKC) is a rare, multisystem, bone marrow failure disease characterized by abnormalities such as in the skin, mucosa, nervous system, and lungs. Here we report a rare case of presumed DKC causing total retinal detachment in the right eye and severe peripheral retinal vascular occlusion in the left eye. A 3-year-old boy was presented with vitreous hemorrhage and total retinal detachment in the right eye and was scheduled to undergo vitreous surgery in the right eye and detailed ophthalmologic examination of the left eye under general anesthesia. Since a systemic examination revealed anemia and marked thrombocytopenia, he underwent a detailed pediatric examination. Although genetic testing revealed no significant pathologic mutations, the presence of shortened telomere length and other clinical findings suggested the possibility of DKC. His right eye had severe proliferative vitreoretinopathy, and retinal reattachment was not achieved with vitreous surgery, thus resulting in phthisis bulbi. The left eye showed a wide retinal avascular area in the temporal retina, retinal neovascularization, and hard exudates on fluorescein fundus angiography and was treated with laser photocoagulation using a binocular indirect ophthalmoscopic photocoagulator. Following laser surgery, the new blood vessels regressed, and the visual acuity was maintained at 1.0. The findings in this rare case indicate that DKC can cause severe retinal vascular occlusion, thus leading to vitreous hemorrhage and retinal detachment. Therefore, early detection with fundus examination and early treatment with photocoagulation are important.