Successful Treatment of Refractory Enterocutaneous Fistula After Esophagectomy Using Soft Coagulation by an Endoscopic and Percutaneous Approach: A Case Report.

BACKGROUND/AIM: Anastomotic leakage (AL) is a serious complication after esophagectomy, and the refractory fistula (RF) following AL is therapeutically challenging with no optimal management strategies known. Thus, new therapeutic options are required for treating RF. CASE REPORT: A 67-year-old man who underwent endoscopic mucosal dissection was subjected to subtotal esophagectomy and reconstruction with a gastric tube through the retrosternal route with cervical anastomosis as additional therapy. On postoperative day 5, leakage from the esophagogastric anastomosis was detected. A refractory enterocutaneous fistula (4 cm in length) developed between the esophagogastric anastomosis (the fistula opening was 1 cm approximately) and cervical skin. The RF did not heal despite the drainage of saliva, enteral nutrition, oral administration of biperiden hydrochloride for orofacial dyskinesia to rest the esophagogastric anastomosis, coagulation factor XIII transvenously, and fibrin glue injection from the opening of the fistula, probably due to difficulty in maintaining the rest of the esophagogastric anastomosis caused by orofacial dyskinesia. On postoperative day 76, soft coagulation to the fistula opening at the esophagogastric anastomosis by an endoscopic approach and to the fistula via the fistula opening at the cervical site by a percutaneous approach was performed. The post-treatment course was uneventful. The RF completely closed immediately after soft coagulation. CONCLUSION: Soft coagulation using endoscopic and percutaneous approaches to RF is a minimally invasive procedure and may be a useful option if the fistula opening of the anastomotic site is small and accessible endoscopically, and there are no vital organs around the fistula.

Survival Benefits of Laparoscopic Gastrectomy in Elderly Patients With Gastric Cancer: Focusing on Preoperative Nutritional and Inflammatory Status.

BACKGROUND/AIM: Laparoscopic gastrectomy (LG) may have greater clinical benefits as a less invasive surgery for elderly patients with gastric cancer (GC). Therefore, we aimed to evaluate the survival benefit of LG in elderly patients with GC, especially focusing on preoperative comorbidities, and nutritional and inflammatory status. PATIENTS AND METHODS: Data collected from 115 patients aged ≥75 years with primary GC who underwent curative gastrectomy, comprising 58 patients who underwent open gastrectomy (OG) and 57 patients who underwent LG, were retrospectively reviewed (total cohort), and 72 propensity-matched patients (matched cohort) were selected for survival analysis. The aim of the study was to determine short- and long-term outcomes, and the clinical markers to identify a population who may benefit from LG in elderly patients. RESULTS: The complication and mortality rates as a short-term outcome in the total cohort and overall survival (OS) as a long-term outcome in the matched cohort did not differ significantly between the groups. In the total cohort, advanced tumor stage and ≥3 comorbidities were independent factors for poor prognosis in terms of OS [hazard ratio (HR)=3.73, 95% confidence interval (CI)=1.78-7.78, p<0.001 and HR=2.50, 95% CI=1.35-4.61, p<0.01, respectively]. The surgical approach was not an independent risk factor for postoperative complications (grade ≥III) and OS. In subgroup analysis of the total cohort, patients with a neutrophil-lymphocyte ratio (NLR) ≥3 in the LG group demonstrated a trend toward greater OS (HR=0.26, 95% CI=0.10-0.64, interaction p<0.05). CONCLUSION: LG might offer greater survival benefits than OG in frail patients such as those with high NLR.

Successful conversion surgery following chemotherapy with an immune checkpoint inhibitor in an older adult patient with stage IVB esophageal squamous cell carcinoma: a case report.

BACKGROUND: Chemotherapy and chemoradiotherapy are common treatments for esophageal squamous cell carcinoma with distant metastasis; however, the prognosis remains poor, and complete remission is difficult to achieve. Here, we report a case of an older adult patient with esophageal squamous cell carcinoma who underwent surgery following combined treatment of immunotherapy and chemotherapy and achieved pathological complete response. CASE PRESENTATION: An 80-year-old woman presenting with difficulty swallowing was referred to our hospital. She was diagnosed with esophageal squamous cell carcinoma with distant metastasis of the lymph node at the dorsal side of the IVC and the left supraclavicular lymph node. She was treated with pembrolizumab, cisplatin, and 5-fluorouracil. After four pharmacotherapy courses, primary tumor and metastatic lymph node shrinkage was observed. The patient underwent thoracoscopic subtotal esophagectomy and regional lymph node dissection. The lymph node at the dorsal side of the IVC was not resected, and the left supraclavicular lymph node was removed. Histological examination revealed complete response with no residual tumor or lymph node metastasis. The patient had no recurrence 10 months postoperatively without adjuvant chemotherapy. CONCLUSIONS: Conversion surgery following preoperative therapy, including immunotherapy, may be an effective treatment strategy for improving survival in patients with esophageal squamous cell carcinoma even among older adult patients.

Survival benefits of gastrectomy compared to conservative observation for older patients with resectable gastric cancer: a propensity score matched analysis.

PURPOSE: Radical gastrectomy is considered the first choice of curative treatment for older patients with gastric cancer (GC). However, there is limited data on the survival benefits of gastrectomy for older patients with GC. METHODS: This was a retrospective observational study where medical records of patients aged ≥ 75 years with clinically resectable primary GC, comprising 115 patients who underwent radical surgery (S group) and 33 patients who received conservative therapy (non-S group) (total cohort) and 44 propensity-matched patients (matched cohort), were reviewed. Survival and independent risk factors, including comorbidities and systemic nutritional and inflammatory statuses, were evaluated. RESULTS: In the total cohort, the 5-year overall survival (OS) in the S group was significantly higher than that in the non-S group (53.7% vs 19.7%, P < 0.0001). In the matched cohort, the 3-year OS in the S group was significantly higher than that in the non-S group (59.4% vs 15.9%, P < 0.01). Multivariate analysis of the total cohort showed that no surgery was an independent prognostic factor for poor OS (hazard ratio (HR) 3.70, 95% confidence interval (CI) 1.91-7.20, P = 0.0001). In the S group in the total cohort, the multivariate analysis showed that renal disease (HR 2.51, 95% CI 1.23-5.12, P < 0.05) was an independent prognostic factor for poor OS. CONCLUSIONS: Gastrectomy for older patients improved the prognosis; however, careful patient selection is essential, especially among those with renal disease.

Administration of C5a Receptor Antagonist Improves the Efficacy of Human Induced Pluripotent Stem Cell-Derived Neural Stem/Progenitor Cell Transplantation in the Acute Phase of Spinal Cord Injury.

Human-induced pluripotent stem cell-derived neural stem/progenitor cell (hiPSC-NS/PC) transplantation during the acute phase of spinal cord injury (SCI) is not effective due to the inflammatory response occurring immediately after SCI, which negatively impacts transplanted cell survival. Therefore, we chose to study the powerful chemoattractant complement C5a as a method to generate a more favorable transplantation environment. We hypothesized that suppression of the inflammatory response immediately after SCI by C5a receptor antagonist (C5aRA) would improve the efficacy of hiPSC-NS/PCs transplantation for acute phase SCI. Here, we evaluated the influence of C5aRA on the inflammatory reaction during the acute phase after SCI, and observed significant reductions in several inflammatory cytokines, macrophages, neutrophils, and apoptotic markers. Next, we divided the SCI mice into four groups: 1) phosphate-buffered saline (PBS) only; 2) C5aRA only; 3) PBS + transplantation (PBS+TP); and 4) C5aRA + transplantation (C5aRA+TP). Immediately after SCI, C5aRA or PBS was injected once a day for 4 consecutive days, followed by hiPSC-NS/PC transplantation or PBS into the lesion epicenter on Day 4. The C5aRA+TP group had better functional improvement compared with the PBS only group. The C5aRA+TP group also had a significantly higher cell survival rate compared with the PBS+TP group. This study demonstrates that administration of C5aRA can suppress the inflammatory response during the acute phase of SCI, while improving the survival rate of transplanted hiPSC-NS/PCs, as well as enhancing motor functional restoration. Human-induced pluripotent stem cell-derived neural stem/progenitor cell transplantation with C5aRA is a promising treatment during the acute injury phase for SCI patients.

Pan-cancer methylome analysis for cancer diagnosis and classification of cancer cell of origin.

The accurate and early diagnosis and classification of cancer origin from either tissue or liquid biopsy is crucial for selecting the appropriate treatment and reducing cancer-related mortality. Here, we established the CAncer Cell-of-Origin (CACO) methylation panel using the methylation data of the 28 types of cancer in The Cancer Genome Atlas (7950 patients and 707 normal controls) as well as healthy whole blood samples (95 subjects). We showed that the CACO methylation panel had high diagnostic potential with high sensitivity and specificity in the discovery (maximum AUC = 0.998) and validation (maximum AUC = 1.000) cohorts. Moreover, we confirmed that the CACO methylation panel could identify the cancer cell type of origin using the methylation profile from liquid as well as tissue biopsy, including primary, metastatic, and multiregional cancer samples and cancer of unknown primary, independent of the methylation analysis platform and specimen preparation method. Together, the CACO methylation panel can be a powerful tool for the classification and diagnosis of cancer.

LOTUS overexpression via ex vivo gene transduction further promotes recovery of motor function following human iPSC-NS/PC transplantation for contusive spinal cord injury.

Functional recovery is still limited mainly due to several mechanisms, such as the activation of Nogo receptor-1 (NgR1) signaling, when human induced pluripotent stem cell-derived neural stem/progenitor cells (hiPSC-NS/PC) are transplanted for subacute spinal cord injury (SCI). We previously reported the neuroprotective and regenerative benefits of overexpression of lateral olfactory tract usher substance (LOTUS), an endogenous NgR1 antagonist, in the injured spinal cord using transgenic mice. Here, we evaluate the effects of lentiviral transduction of LOTUS gene into hiPSC-NS/PCs before transplantation in a mouse model of subacute SCI. The transduced LOTUS contributes to neurite extension, suppression of apoptosis, and secretion of neurotrophic factors in vitro. In vivo, the hiPSC-NS/PCs enhance the survival of grafted cells and enhance axonal extension of the transplanted cells, resulting in significant restoration of motor function following SCI. Therefore, the gene transduction of LOTUS in hiPSC-NS/PCs could be a promising adjunct for transplantation therapy for SCI.

Successful outcome of retrograde pancreatojejunostomy for chronic pancreatitis and infected pancreatic cysts: A case report.

BACKGROUND: Chronic pancreatitis occasionally requires surgical treatment that can be performed with various techniques. Often, this type of surgery presents with postoperative complications. We report a case of a successful retrograde pancreatojejunostomy for chronic pancreatitis and infected pancreatic cysts. CASE SUMMARY: A 62-year-old male with a 10-year history of chronic pancreatitis presented with epigastric pain for one week and a 20 kg weight loss over one year. Computed tomography showed stones in the pancreas (mainly the head), expansion of the main pancreatic duct, and thinning of the pancreatic parenchyma. Magnetic resonance imaging showed infected pancreatic cysts connected to the stomach with a fistula from the splenic hilum to the caudal portion of the liver's lateral segment. An endoscopic retrograde pancreatography was performed; the guide wires could not pass through the stones in the pancreas and therefore, drainage of the main pancreatic duct was not achieved. Next, a distal pancreatomy and splenectomy were performed; however, the pancreatic juice in the remaining parenchyma was blocked by the stones. Hence, we performed a retrograde pancreatojejunostomy and Roux-en-Y anastomosis. The patient had no postoperative complications and was discharged from the hospital on postoperative day 14. CONCLUSION: A distal pancreatomy, retrograde pancreatojejunostomy, and Roux-en-Y anastomosis could be an effective surgical procedure for intractable chronic pancreatitis.

Oxysterol binding protein-like 3 (OSBPL3) is a novel driver gene that promotes tumor growth in part through R-Ras/Akt signaling in gastric cancer.

Gastric cancer (GC) is one of the most lethal malignant tumors. To improve the prognosis of GC, the identification of novel driver genes as therapeutic targets is in urgent need. Here, we aimed to identify novel driver genes and clarify their roles in gastric cancer. OSBPL3 was identified as a candidate driver gene by in silico analysis of public genomic datasets. OSBPL3 expression was analyzed by RT-qPCR and immunohistochemistry in GC cells and tissues. The biological functions and mechanisms of OSBPL3 in GC were examined in vitro and in vivo using GC cells. The association between OSBPL3 expression and clinical outcome in GC patients was also evaluated. Overexpression of OSBPL3 was detected in GC cells with OSBPL3 DNA copy number gains and promoter hypomethylation. OSBPL3-knockdown reduced GC cell growth in vitro and in vivo by inhibiting cell cycle progression. Moreover, an active Ras pull-down assay and western blotting demonstrated that OSBPL3 activates the R-Ras/Akt signaling pathway in GC cells. In a clinical analysis of two GC datasets, high OSBPL3 expression was predictive of a poor prognosis. Our findings suggest that OSBPL3 is a novel driver gene stimulating the R-Ras/Akt signaling pathway and a potential therapeutic target in GC patients.

First-in-human clinical trial of transplantation of iPSC-derived NS/PCs in subacute complete spinal cord injury: Study protocol.

INTRODUCTION: Our group has conducted extensive basic and preclinical studies of the use of human induced pluripotent cell (iPSC)-derived neural stem/progenitor cell (hiPSC-NS/PC) grafts in models of spinal cord injury (SCI). Evidence from animal experiments suggests this approach is safe and effective. We are preparing to initiate a first-in-human clinical study of hiPSC-NS/PC transplantation in subacute SCI. SETTING: NS/PCs were prepared at a Good Manufacturing Practice-grade cell processing facility at Osaka National Hospital using a clinical-grade integration-free hiPSC line established by the iPSC Stock Project organized by the Kyoto University Center for iPS Cell Research and Application. After performing all quality checks, the long-term safety and efficacy of cells were confirmed using immunodeficient mouse models. METHODS: The forthcoming clinical study uses an open-label, single-arm design. The initial follow-up period is 1 year. The primary objective is to assess the safety of hiPSC-NS/PC transplantation in patients with subacute SCI. The secondary objective is to obtain preliminary evidence of its impact on neurological function and quality-of-life outcomes. Four patients with C3/4-Th10 level, complete subacute (within 24 days post-injury) SCI will be recruited. After obtaining consent, cryopreserved cells will be thawed and prepared following a multi-step process including treatment with a γ-secretase inhibitor to promote cell differentiation. A total of 2 × 106 cells will be transplanted into the injured spinal cord parenchyma 14-28 days post-injury. Patients will also receive transient immunosuppression. This study protocol has been reviewed and approved by the Certified Committee for Regenerative Medicine and the Japanese Ministry of Health, Labor and Welfare (University Hospital Medical Information Network Clinical Trials Registry [UMIN-CTR] number, UMIN000035074; Japan Registry of Clinical Trials [jRCT] number, jRCTa031190228). DISCUSSION/CONCLUSION: We plan to start recruiting a patient as soon as the COVID-19 epidemic subsides. The primary focus of this clinical study is safety, and the number of transplanted cells may be too low to confirm efficacy. After confirming safety, a dose-escalation study is planned.

The Evolving Genomic Landscape of Esophageal Squamous Cell Carcinoma Under Chemoradiotherapy.

Esophageal squamous cell carcinoma (ESCC) often recurs after chemoradiotherapy, and the prognosis of ESCC after chemoradiotherapy has not improved over the past few decades. The mutation process in chemoradiotherapy-resistant clones and the functional relevance of genetic alterations remain unclear. To address these problems, we performed whole-exome sequencing of 52 tumor samples from 33 patients with ESCC who received radiotherapy combined with 5-fluorouracil/platinum. In multiregion analyses of pretreatment and locally recurrent lesions from five cases, most driver gene-altered clones remained under chemoradiotherapy selection pressure, while few driver gene alterations were acquired at recurrence. The mutation signatures of recurrent ESCC, including increased deletion frequency and platinum dose-dependent base substitution signatures, were substantially different from those of primary ESCC and reflected the iatrogenic impacts of chemoradiotherapy. Single-region analysis of 28 pretreatment tumors indicated that focal copy-number gain at the MYC locus was significantly associated with poor progression-free survival and overall survival after chemoradiotherapy. MYC gain remained throughout the chemoradiotherapy course and potentially contributes to intrinsic resistance to chemoradiotherapy. Consistent with these findings, MYC copy number and mRNA and protein levels in ESCC cell lines correlated positively with resistance to radiotherapy, and MYC knockdown improved sensitivity to radiotherapy. Overall, these data characterize the clonal evolution process induced by chemoradiotherapy and clinically relevant associations for genetic alterations in ESCC. These findings increase our understanding of therapeutic resistance and support the rationale for precision chemoradiotherapy. SIGNIFICANCE: Whole-exome sequencing reveals the genetic evolution of ESCC during chemoradiotherapy, highlighting MYC gain in pretreatment tumors as a potential marker of therapy resistance.

Schwannoma mimicking pancreatic carcinoma: A case report.

BACKGROUND: Schwannoma of the pancreas is extremely rare. We report a case of pancreatic schwannoma that was difficult to distinguish from pancreatic carcinoma before surgery. CASE SUMMARY: A 66-year-old male underwent a right-lobe hepatectomy for hepatocellular carcinoma. Post-surgical computed tomography showed a 10 mm long solid mass with ischemia, with no expansion into the main pancreatic duct. Upon magnetic resonance cholangiopancreatography, the tumor had high signal intensity in diffusion weighted images, consistent with pancreatic carcinoma. Endoscopic ultrasound (EUS) was performed to obtain more information about the tumor, and showed a 14 mm solid and hypoechoic mass in the pancreatic body. Contrast enhanced EUS revealed that the tumor showed a hyperechoic mass in the early phase, and the contrasting effect continuation was very short; findings also consistent with pancreatic carcinoma. Thus, we preoperatively diagnosed his condition as a pancreatic carcinoma and performed distal pancreatectomy with splenectomy. Microscopic examination showed that the tumor was in fact a benign schwannoma. Histology showed a proliferation of spindle-shaped cell in a vague fascicular and haphazard pattern, with palisading arrangement. CONCLUSION: Schwannoma of the pancreas is very rare, however, clinicians should consider schwannoma as the differential diagnosis for pancreatic tumors.

Cancer-associated Fibroblast-derived Spondin-2 Promotes Motility of Gastric Cancer Cells.

BACKGROUND/AIM: Peritoneal dissemination (PD) occurs frequently in gastric cancer (GC) and is fatal. The interactions between tumor cells and stromal cells are critical for cancer progression. Our aim was to identify a novel PD-associated gene derived from stromal cells in GC. MATERIALS AND METHODS: Among the candidate PD-associated genes identified in our previous study, we focused on spondin-2 (SPON2), an extracellular matrix-secreted protein. Clinicopathological and prognostic analyses of SPON2 mRNA expression were performed using GC datasets. Localization of SPON2 expression was assessed by immunohistochemistry. In vitro migration assay and immunofluorescence staining were also conducted using GC cell lines. RESULTS: SPON2 was expressed in and secreted from cancer-associated fibroblasts in GC. High expression of SPON2 in tumor tissues was correlated with PD, tumor size and poor prognosis in GC. The motility of GC cells was increased by treatment with a SPON2 recombinant protein in vitro. CONCLUSION: Cancer-associated fibroblast-derived SPON2 may promote PD, in part, by facilitating GC cell motility and serve as a predictive marker for PD in GC.

The influence of the interval between percutaneous transhepatic gallbladder drainage and cholecystectomy on perioperative outcomes: a retrospective study.

BACKGROUND: Percutaneous transhepatic gallbladder drainage (PTGBD) is recommended for acute cholecystitis patients at high risk for surgical treatment. However, there is no evidence about the best timing of surgery after PTGBD. Here, we retrospectively investigated the influence of the interval between PTGBD and surgery on perioperative outcomes and examined the optimal timing of surgery after PTGBD. METHODS: We performed a retrospective analysis of 22 patients who underwent cholecystectomy after PTGBD from January 2008 to August 2019. We examined perioperative factors between patients with an interval of ≤ 7 days between PTGBD and cholecystectomy (≤ 7-day group; n = 12) and those with an interval of ≥ 8 days (≥ 8-day group; n = 10). Moreover, we also examined perioperative factors between patients with an interval of ≤ 14 days from PTGBD to cholecystectomy (≤ 14-day group; n = 10) and those with an interval of ≥ 15 days (≥ 15-day group; n = 12). RESULTS: Of the 22 patients, 9 had Grade I cholecystitis, 12 had Grade II cholecystitis, and 2 had Grade III cholecystitis. Nine patients had high-grade cholecystitis before PTGBD and 13 had a poor general condition. We examined perioperative factors between patients with an interval of ≤ 7 days between PTGBD and cholecystectomy (≤ 7-day group; n = 12) and those with an interval of ≥ 8 days (≥ 8-day group; n = 10). The C-reactive protein (CRP) level before surgery was significantly higher (12.70 ± 1.95 mg/dL vs. 1.13 ± 2.13 mg/dL, p = 0.0007) and the total hospitalization was shorter (17.6 ± 8.0 days vs. 54.1 ± 8.8 days, p = 0.0060) in the ≤ 7-day group than in the ≥ 8-day group. We also examined perioperative factors between patients with an interval of ≤ 14 days from PTGBD to cholecystectomy (≤ 14-day group; n = 14) and those with an interval of ≥ 15 days (≥ 15-day group; n = 8). The CRP level before surgery was significantly higher (11.13 ± 2.00 mg/dL vs. 0.99 ± 2.64 mg/dL, p = 0.0062) and the total hospitalization was shorter (19.5 ± 7.2 days vs. 59.9 ± 9.5 days, p = 0.0029) in the ≤ 14-day group than in the ≥ 15-day group. However, there were no significant differences between the ≤ 14-day group and the ≥ 15-day group in the levels of hepatic enzymes before surgery, adhesion grade, amount of bleeding during surgery, operative duration, frequency of surgical complications, or length of hospitalization after surgery. CONCLUSIONS: The interval between PTGBD and surgery has little influence on perioperative outcomes.

Intra-abdominal Desmoid-Type Fibromatosis Mimicking Diverticulitis With Abscess: A Case Report.

BACKGROUND: Intra-abdominal desmoid-type fibromatosis (DF) rarely necessitates emergency surgery. However, the condition is difficult to diagnose preoperatively and can become life-threatening if left untreated. CASE REPORT: A 46-year-old man complained of fever and right lower quadrant pain. In computed tomography, the mesenteric side of the ascending colon demonstrated air and fluid collections, suggesting diverticulitis with abscess. After 2 weeks of conservative treatment with fasting, the patient started to consume food; nonetheless, fever returned. Colonoscopy and contrast enema detected a fistula extending from the ascending colon to the abscess, with no surrounding lesions. Surgery was then performed because the abscess was refractory. During laparotomy, the scar tissue of the abscess was found to be attached to the lateral wall of the ascending colon. Hence, right colectomy combined with abscess resection was performed. Histopathological findings revealed DF in the mesentery. CONCLUSION: Although rare, DF should be included in the preoperative differential diagnosis of intra-abdominal abscesses.

A robust culture system to generate neural progenitors with gliogenic competence from clinically relevant induced pluripotent stem cells for treatment of spinal cord injury.

Cell-based therapy targeting spinal cord injury (SCI) is an attractive approach to promote functional recovery by replacing damaged tissue. We and other groups have reported the effectiveness of transplanting neural stem/progenitor cells (NS/PCs) derived from human induced pluripotent stem cells (hiPSCs) in SCI animal models for neuronal replacement. Glial replacement is an additional approach for tissue repair; however, the lack of robust procedures to drive iPSCs into NS/PCs which can produce glial cells has hindered the development of glial cell transplantation for the restoration of neuronal functions after SCI. Here, we established a method to generate NS/PCs with gliogenic competence (gNS/PCs) optimized for clinical relevance and utilized them as a source of therapeutic NS/PCs for SCI. We could successfully generate gNS/PCs from clinically relevant hiPSCs, which efficiently produced astrocytes and oligodendrocytes in vitro. We also performed comparison between gNS/PCs and neurogenic NS/PCs based on single cell RNA-seq analysis and found that gNS/PCs were distinguished by expression of several transcription factors including HEY2 and NFIB. After gNS/PC transplantation, the graft did not exhibit tumor-like tissue formation, indicating the safety of them as a source of cell therapy. Importantly, the gNS/PCs triggered functional recovery in an SCI animal model, with remyelination of demyelinated axons and improved motor function. Given the inherent safety of gNS/PCs and favorable outcomes observed after their transplantation, cell-based medicine using the gNS/PCs-induction procedure described here together with clinically relevant iPSCs is realistic and would be beneficial for SCI patients.

Potential association of LOXL1 with peritoneal dissemination in gastric cancer possibly via promotion of EMT.

BACKGROUND: Peritoneal dissemination (PD) frequently occurs in gastric cancer (GC) and is incurable. In this study, we aimed to identify novel PD-associated genes and clarify their clinical and biological significance in GC. MATERIALS AND METHODS: We identified LOXL1 as a PD-associated candidate gene by in silico analysis of GC datasets (highly disseminated peritoneal GC cell line and two freely available GC datasets, GSE15459 and TCGA). Next, we evaluated the clinical significance of LOXL1 expression using RT-qPCR and immunohistochemistry staining (IHC) in a validation cohort (Kyushu cohort). Moreover, we performed gene expression analysis, including gene set enrichment analysis (GSEA) with GSE15459 and TCGA datasets. Finally, we performed a series of in vitro experiments using GC cells. RESULTS: In silico analysis showed that LOXL1 was overexpressed in tumor tissues of GC patients with PD and in highly disseminated peritoneal GC cells, relative to that in the control GC patients and cells, respectively. High expression of LOXL1 was a poor prognostic factor in the TCGA dataset. Next, IHC showed that LOXL1 was highly expressed in GC cells. High LOXL1 mRNA expression was associated with poorly differentiated histological type, lymph node metastasis, and was an independent poor prognostic factor in the Kyushu validation cohort. Moreover, LOXL1 expression was positively correlated with the EMT (epithelial-mesenchymal transition) gene set in GSEA. Finally, LOXL1-overexpressing GC cells changed their morphology to a spindle-like form. LOXL1 overexpression reduced CDH1 expression; increased the expression of VIM, CDH2, SNAI2, and PLS3; and promoted the migration capacity of GC cells. CONCLUSIONS: LOXL1 is associated with PD in GC, possibly through the induction of EMT.

The Expression Level of PD-L1 (CD274) mRNA in Peripheral Blood Is a Potential Biomarker for Predicting Recurrence in Breast Cancer.

BACKGROUND/AIM: Programmed death-ligand 1 (PD-L1/CD274) elicits T-cell anergy, leading to immune suppression. We aimed to determine the prognostic relevance of PD-L1 expression in the blood of breast cancer (BC) patients. MATERIALS AND METHODS: We measured PD-L1 mRNA expression in blood and tumor tissues of BC patients using RT-qPCR and a dataset from The Cancer Genome Atlas, and performed a survival analysis of PD-L1 expression in the blood of 330 BC patients. Flow cytometric analysis was performed using blood cells. RESULTS: No statistical difference in PD-L1 expression was seen between normal controls and BC in blood or tissues. There was a significant positive correlation between the PD-L1 expression levels in blood and tissues. Decreased PD-L1 expression in blood or tissues was associated with poor recurrence-free survival. PD-L1 is mainly expressed in polymorphonuclear leukocytes. CONCLUSION: Low expression of PD-L1 in the blood could serve as a biomarker of poor prognosis in BC patients.

Prognostic Significance of PD-1, PD-L1 and CD8 Gene Expression Levels in Gastric Cancer.

INTRODUCTION: Anti-programmed cell death 1 (PD-1) therapies have shown promising clinical activity against gastric cancer (GC). We evaluated the clinical significance of immune-related gene expression in GC tissues to better understand the tumor immune microenvironment. METHODS: PD-1, PD-1 ligand 1 (PD-L1) and CD8 mRNA levels and clinicopathological factors, including survival, were examined by quantitative RT-PCR in 155 GC patients who underwent surgery. PD-1 and PD-L1 expression in tumor tissue from 24 GC patients was investigated by immunohistochemical analysis. RESULTS: PD-1, PD-L1 and CD8 mRNA levels were significantly lower in tumor tissue than in normal tissue (p < 0.0001, p < 0.05, and p < 0.0001). GC patients with low PD-1, PD-L1 and CD8 mRNA levels had significantly poorer overall survival (OS) than those with high PD-1, PD-L1 and CD8 mRNA levels, respectively (p < 0.001, p < 0.01 and p < 0.05). Low PD-1, PD-L1 and CD8 mRNA levels were more significantly associated with poor prognosis in undifferentiated-type GC patients than in differentiated-type GC patients (PD-1: differentiated p = 0.0071 vs. undifferentiated p = 0.0024; PD-L1: p = 0.6527 vs. p < 0.0001; CD8: p = 0.4465 vs. p < 0.05). Multivariate analysis showed that lymph node metastasis, peritoneal dissemination, distant metastasis, low PD-1 mRNA levels and low CD8 mRNA levels were independent prognostic factors for worse OS (low PD-1 mRNA level: OR 2.16, 95% CI 1.10-4.58, p < 0.05; low CD8 mRNA level: OR 2.55, 95% CI 1.12-6.90, p < 0.05). PD-1 and PD-L1 mRNA levels in immune cells were significantly associated with PD-1 and PD-L1 protein levels (both p < 0.05), respectively. CONCLUSIONS: PD-1, PD-L1 and CD8 mRNA levels may reflect antitumor immunity in GC, and low PD-1 and CD8 mRNA levels are potential predictive biomarkers for poor prognosis in GC patients who underwent surgery.

Circulating PD-1 mRNA in Peripheral Blood is a Potential Biomarker for Predicting Survival of Breast Cancer Patients.

BACKGROUND: Programmed cell death 1 (PD-1) inhibitors have shown significant therapeutic promise in various cancers. However, the clinical significance of PD-1 expression remains not fully understood. In this study, we evaluated the clinical and prognostic relevance of PD-1 expression in breast cancer (BC). METHODS: First, we analyzed PD-1 mRNA expression in BC tissues and performed a survival analysis using a dataset from The Cancer Genome Atlas. Next, we measured PD-1 mRNA expression in peripheral blood (PB) in BC patients by quantitative reverse-transcription polymerase chain reaction. We performed a survival analysis and evaluated the association between PD-1 mRNA expression in PB and the clinicopathological features of 372 BC patients who underwent curative resection. Flow cytometry (FCM) analysis was performed to identify PD-1-expressing cells in PB. Finally, we determined whether there was a correlation of PD-1 mRNA expression in PB and tumor tissue. RESULTS: PD-1 mRNA expression was significantly higher in tumor tissues compared with normal tissues. Decreased PD-1 mRNA expression in tumor tissue was associated with poor overall survival (OS). PD-1 mRNA expression in PB of BC patients was higher than that of healthy volunteers, and increased PD-1 mRNA expression in PB was associated with poor OS. FCM revealed that PD-1 was mostly expressed on T cells in PB, predominantly in CD4+ T cells. PD-1 mRNA expression in PB was negatively correlated with PD-1 mRNA expression in tumor tissue. CONCLUSION: High expression of PD-1 mRNA in preoperative PB could serve as an effective biomarker that indicates poor prognosis in BC.