Lipocalin-2 negatively regulates epithelial-mesenchymal transition through matrix metalloprotease-2 downregulation in gastric cancer.

BACKGROUND: Although the role of Lipocalin-2 (LCN2) in cancer development has been focused on recent studies, the molecular mechanisms and clinical relevance of LCN2 in gastric cancer (GC) still remain unclear. METHODS: Transcriptome analysis of GC samples from public human data was performed according to Lauren's classification and molecular classification. In vitro, Western blotting, RT-PCR, wound healing assay and invasion assay were performed to reveal the function and mechanisms of LCN2 in cell proliferation, migration and invasion using LCN2 knockdown cells. Gene set enrichment analysis (GSEA) of GC samples from public human data was analyzed according to LCN2 expression. The clinical significance of LCN2 expression was investigated in GC patients from public data and our hospital. RESULTS: LCN2 was downregulated in diffuse-type GC, as well as in Epithelial-Mesenchymal Transition (EMT) type GC. LCN2 downregulation significantly promoted proliferation, invasion and migration of GC cells. The molecular mechanisms of LCN2 downregulation contribute to Matrix Metalloproteinases-2 (MMP2) stimulation which enhances EMT signaling in GC cells. GSEA revealed that LCN2 downregulation in human samples was involved in EMT signaling. Low LCN2 protein and mRNA levels were significantly associated with poor prognosis in patients with GC. LCN2 mRNA level was an independent prognostic factor for overall survival in GC patients. CONCLUSIONS: LCN2 has a critical role in EMT signaling via MMP2 activity during GC progression. Thus, LCN2 might be a promising therapeutic target to revert EMT signaling in GC patients with poor outcomes.

[A Case of Long-Term Survival after Multidisciplinary Treatment for Neuroendocrine Carcinoma of the Anal Canal].

A 75-year-old man presented to a local clinic with anal pain, and a palpable anal tumor on was found on digital examination of the rectum. A biopsy led to the diagnosis of neuroendocrine carcinoma. Besides the anal tumor, an right-inguinal lymph node was revealed on computed tomography(CT). Positron emission tomography-CT showed abnormal uptake in the 2 regions. He was diagnosed with lymph node metastases from anal canal carcinoma, and an abdominoperineal resection was performed. The resected specimen included the anal canal tumor with a size of 27×18 mm in diameter. On immunohistochemistry, the anal canal tumor was strongly positive for synaptophysin and positive for chromogranin A, with a Ki- 67 positivity index of 70%. After the surgery, he was administered chemotherapy with 4 courses of cisplatin and CPT-11. One year after the surgery, CT revealed lymph node recurrence. Therefore, cisplatin and CPT-11 therapy was repeated. After 11 courses of the cisplatin and CPT-11 treatment, tumor regrowth was still detected. The treatment protocol was changed to an amrubicin monotherapy regimen. However, the patient's general condition worsened after the therapies, and he died 38 months after the surgery.

[A Case of Long-Term Survival after Chemotherapy for Gastric Cancer with Peritoneal Dissemination].

The patient was a 58-year-old man who had undergone wide gastrectomy for gastric ulcer at 22 years of age. Endoscopic examination revealed an advanced type 3 gastric cancer in the anastomotic region. We performed total gastrectomy and D1 lymph node dissection because of the bleeding from the tumor, although peritoneal dissemination was found during the surgery. A post-operative pathological diagnosis of gastric cancer pT4b(SI, abdominal wall)N0M1(PER), pStage Ⅳ, was made. After the surgery, he was administered chemotherapy with S-1 and cisplatin. After 9 courses of the treatment, the treatment protocol was changed to an S-1 therapy regimen because of general fatigue. Four years and 8 months after the surgery, the tumor marker had increased, and CT scans revealed a dissemination nodule at the left back side of the bladder. Therefore, PTX plus Rmab therapy was administered as a second-line chemotherapy. Treatment with PTX plus Rmab resulted in tumor reduction, with an improvement of the QOL of the patient; partial response was maintained for 12 months. After 16 courses of the PTX plus Rmab treatment, tumor regrowth was detected. The treatment protocol was changed again to a nivolumab regimen. After 4 courses, the tumor marker was normalized, and CT scans revealed that the peritoneal dissemination had shrunk. Although the prognosis of gastric cancer with dissemination is very poor, it is possible to prolong survival with chemotherapy.

[Laparoscopic Surgical Treatment of Differentiated Intramucosal Gastric Cancer with Lymph Node Metastasis-A Case Report].

A 78‒year‒old man was admitted to our hospital with the chief complaint of 5 kg weight loss in 6 months. An esophagogastroduodenoscopy revealed a 0‒Ⅱa lesion in the posterior wall of the antrum, and biopsy findings showed a well‒differentiated adenocarcinoma. Endoscopic ultrasonography did not show an obvious invasion of the submucosal layer. Contrast‒ enhanced abdominal computed tomography(CT)revealed an enlargement of the #11p lymph node to approximately 30 mm, and positron emission tomography(PET)‒CT showed an accumulation in the same lymph node. Since no other apparent distant metastases were observed, laparoscopic distal gastrectomy and D2 dissection were performed. The postoperative pathological diagnosis was L, 7×8 mm, 0‒Ⅱa, tub1, pT1a, ly0, v0, pPM0(73 mm), pDM0(35 mm), N2, and pStage ⅡA. We report this case because the successful laparoscopic resection of a differentiated gastric mucosal cancer with lymph node metastasis has been considered to be extremely rare.

[Choroidal metastasis from gastric cancer 8 years after surgery].

A man in his 50s underwent total gastrectomy with D2 lymphadenectomy for gastric cancer 8 years ago. The pathological stage was pT3N3bM0, pStage IIIC. He took tegafur, gimeracil, and oteracil potassium (S-1) as adjuvant chemotherapy for the next 3 years at his own request. No recurrence was observed for 8 years after surgery, but then a recurrent lesion near the anastomosis and multiple metastases were detected on abdominal computed tomography. He started treatment with S-1 plus oxaliplatin. One month later, he experienced right-sided visual disturbance. Ophthalmological tests revealed a tumor on his choroid. Three months later, the recurrent tumor and metastatic lesions shrank, and his visual symptoms improved. Therefore, we diagnosed choroidal metastasis from gastric cancer. Choroidal metastasis from the gastrointestinal tract is extremely rare. We discuss this case along with the relevant literature.

Serine threonine kinase 11/liver kinase B1 mutation in sporadic scirrhous-type gastric cancer cells.

Scirrhous-type gastric carcinoma (SGC), which is characterized by the rapid proliferation of cancer cells accompanied by extensive fibrosis, shows extremely poor survival. A reason for the poor prognosis of SGC is that the driver gene responsible for SGC has not been identified. To identify the characteristic driver gene of SGC, we examined the genomic landscape of six human SGC cell lines of OCUM-1, OCUM-2M, OCUM-8, OCUM-9, OCUM-12 and OCUM-14, using multiplex gene panel testing by next-generation sequencing. In this study, the non-synonymous mutations of serine threonine kinase 11/liver kinase B1 (STK11/LKB1) gene were detected in OCUM-12, OCUM-2M and OCUM-14 among the six SGC cell lines. Capillary sequencing analysis confirmed the non-sense or missense mutation of STK11/LKB1 in the three cell lines. Western blot analysis showed that LKB1 expression was decreased in OCUM-12 cells and OCUM-14 cells harboring STK11/LKB1 mutation. The mammalian target of rapamycin (mTOR) inhibitor significantly inhibited the proliferation of OCUM-12 and OCUM-14 cells. The correlations between STK11/LKB1 expression and clinicopathologic features of gastric cancer were examined using 708 primary gastric carcinomas by immunochemical study. The low STK11/LKB1 expression group was significantly associated with SGC, high invasion depth and frequent nodal involvement, in compared with the high STK11/LKB1 expression group. Collectively, our study demonstrated that STK11/LKB1 mutation might be responsible for the progression of SGC, and suggested that mTOR signaling by STK11/LKB1 mutation might be one of therapeutic targets for patients with SGC.

Circulating tumor cells with FGFR2 expression might be useful to identify patients with existing FGFR2-overexpressing tumor.

Fibroblast growth factor receptor (FGFR) is associated with proliferation, migration, and angiogenesis of carcinomas, and FGFR signaling inhibitors are considered a key drug for the treatment of solid tumors with FGFR overexpression. Amplification of FGFR2 is reportedly identified in 3%-10% of gastric cancers (GCs). The aim of this study is to clarify whether the identification of the circulating tumor cells (CTCs) with FGFR2 overexpression is useful to detect patients with FGFR2-overexpressing GC. One hundred GC patients who underwent gastrectomy were enrolled. A total volume of 8 mL of peripheral blood was collected from each patient just before gastrectomy, and mononuclear cells were enriched by Ficol density gradient centrifugation. These cells were immunostained with PI/CD45/EpCAM/FGFR2. The number of CTCs with FGFR2 expression in each sample was enumerated by FACScan. The FGFR2 expression level of the resected primary tumor was assessed by immunohistochemistry. The number of FGFR2-positive CTCs in the GC patients' peripheral blood was significantly correlated with the FGFR2 expression level of the primary GC. The relapse-free survival of the patients with FGFR2-positive CTCs (≥5 cells/10 mL blood) was significantly poorer (P = .018, log-rank) than that of the patients without FGFR2-positive CTCs (<5 cell/10 mL blood). These findings suggested that the determination of FGFR2-positive CTCs might help identify an existing tumor with FGFR2 overexpression.

[A Case of Hypophysitis Due to Immune Check Point Inhibitor Treatment].

The patient was a man in his 70s with bone metastasis from renal cell carcinoma who had received immune checkpoint inhibitors(ICI)therapy. After 2 courses of chemotherapy, he was admitted to our hospital with diverticulitis. His diverticulitis could be treated with antibiotics, but he presented with severe hyponatremia and consciousness disorder during hospitalization. Brain MRI showed pituitary swelling, and his serum TSH, ACTH, cortisol levels decreased. We therefore diagnosed him with hypopituitarism due to ICIs. Hydrocortisone improved his hyponatremia and consciousness disorder. Endocrine stimulation tests revealed no reaction of ACTH, and low-level reactions of TSH, LH and FSH, ICIs cause many types of immune- related adverse events(irAEs). The indications for ICI therapy are expanding; thus, we can expect to experience more cases of serious irAEs in association with ICI treatment. Further studies should be performed to improve our understanding of irAEs.

[A Case of HER2-Positive Gastric Cancer with Multiple Liver Metastases Treated with Curative Conversion Therapy after Chemotherapy].

A 66-year-old man underwent chemotherapy with S-1 plus cisplatin plus trastuzumab to treat advanced gastric cancer that was diagnosed as cStage Ⅳ adenocarcinoma(T3N1M1[P0, CYX, H1]). After 8 courses, liver metastases were absent on contrast-enhanced MRI. The patient underwent a laparoscopic distal gastrectomy with D2 lymphadenectomy. The gross appearance of the surgically resected specimen showed a shrunk gastric tumor measuring 1 mm. The postoperative course was uneventful, and the patient has been well, receiving maintenance chemotherapy of S-1 plus trastuzumab without evidence of recurrence for 15 months following the operation. Conversion surgery following chemotherapy might be an effective treatment for patients with advanced gastric cancer; however, further studies are needed to establish this treatment strategy.

Establishment of a New Scirrhous Gastric Cancer Cell Line with FGFR2 Overexpression, OCUM-14.

BACKGROUND: The prognosis of scirrhous gastric carcinoma (SGC), which is characterized by rapid infiltration and proliferation of cancer cells accompanied by extensive stromal fibrosis, is extremely poor. In this study, we report the establishment of a unique SGC cell line from a gastric cancer patient in whom an autopsy was performed. METHODS: A new SGC cell line, OCUM-14, was established from malignant ascites of a male patient with SGC. A postmortem autopsy was performed on the patient. Characterization of OCUM-14 cells was analyzed by microscopic examination, reverse transcription polymerase chain reaction, fluorescence in situ hybridization analysis, immunohistochemical examination, CCK-8 assay, and in vivo assay. RESULTS: OCUM-14 cells grew singly or in clusters, and were floating and round-shaped. Most OCUM-14 cells had many microvilli on their surfaces. The doubling time was 43.1 h, and the subcutaneous inoculation of 1.0 × 107 OCUM-14 cells into mice resulted in 50% tumor formation. mRNA expressions of fibroblast growth factor receptor 2 (FGFR2) and human epidermal growth factor receptor 2 (HER2) were observed in OCUM-14 cells. FGFR2, but not HER2, overexpression was found in OCUM-14 cells. The heterogeneous overexpression of FGFR2 was also found in both the primary tumor and metastatic lesions of the peritoneum, lymph node, bone marrow, and lung of the patient. The FGFR2 inhibitors AZD4547 and BGJ398 significantly decreased the growth of OCUM-14 cells, while paclitaxel and 5-fluorouracil significantly decreased the proliferation of OCUM-14 cells, but cisplatin did not. CONCLUSION: A new gastric cancer cell line, OCUM-14, was established from SGC and showed FGFR2 overexpression. OCUM-14 might be useful for elucidating the characteristic mechanisms of SGC and clarifying the effect of FGFR2 inhibitors on SGC.

CD9-positive exosomes from cancer-associated fibroblasts stimulate the migration ability of scirrhous-type gastric cancer cells.

This corrects the article DOI: 10.1038/bjc.2017.85.

Significance of the Lysyl Oxidase Members Lysyl Oxidase Like 1, 3, and 4 in Gastric Cancer.

BACKGROUND/AIMS: Lysyl oxidase (LOX) family members play a key role in modifying the primary tumor microenvironment by crosslinking collagens and elastin in the extracellular matrix. The aim of this study was to analyze the LOX-like (LOXL)1, LOXL3, and LOXL4 expressions in gastric cancer tissue by immunohistochemical staining. METHODS: The correlations between the clinicopathological features of 597 primary gastric carcinomas and LOX family members - LOXL1, LOXL3, and LOXL4 - were investigated by immunohistochemical studies. The effect of the transforming growth -factor ß1 (TGFß1) on the expressions of LOXL1, LOXL3, and LOXL4 in gastric cancer was examined using diffuse-type gastric cancer cell lines in vitro. RESULTS: The expressions of LOXL1, LOXL3, and LOXL4 were correlated with T invasion, lymph node metastasis, and lymphatic and venous invasion. LOXL1 expression was associated with histological intestinal-type and expanding growth patterns. The overall survival of patients with LOXL1-, LOXL3-, or LOXL4-positive cancer was poorer than those with negative cancer. LOXL3 and LOXL4 mRNA expressions were significantly high in diffuse-type gastric cancer cells with high invasion ability. TGFß decreased the LOXL1 expression and increased LOXL3 and LOXL4 expression. CONCLUSION: LOXL1, LOXL3, and LOXL4 expressions are associated with distant metastasis of gastric cancer.

Pyruvate kinase isozyme M2 and glutaminase might be promising molecular targets for the treatment of gastric cancer.

The aim of this study was to analyze the significance of glucose metabolism-related enzymes in the proliferation of gastric cancer under hypoxia. Four hypoxia-resistant gastric cancer cell lines and four parent cell lines were used. Reverse transcription-PCR was used to evaluate the mRNA expression levels of the following metabolism-related enzymes: pyruvate kinase isozyme M2 (PKM2), glutaminase (GLS), enolase 1 (ENO1), glucose-6-phosphate dehydrogenase (G6PDH), and PKM1. The effects of these enzymes on the proliferation of gastric cancer cells were examined using siRNAs, shikonin as a PKM2 inhibitor, or BPTES as a GLS inhibitor, in vitro and in vivo. Levels of both PKM2 and GLS mRNA were significantly high in all hypoxia-resistant cell lines, compared with those of their parent cells. Knockdown of PKM2 and GLS significantly decreased the proliferation of all hypoxia-resistant cells. The combination of siPKM2 and siGLS significantly decreased proliferation compared with treatment by siPKM2 or siGLS alone. The knockdown of ENO1, G6PDH, or PKM1 did not decrease the proliferation of all hypoxia-resistant cells. Combination treatment using shikonin and BPTES inhibited the proliferation of all hypoxia-resistant cancer cells more than that by either agent alone. The in vivo study indicated that the tumor size treated by the combination of shikonin and BPTES was significantly smaller than that of vehicle-treated group. These findings suggested that PKM2 and GLS might play important roles in the proliferation of hypoxic gastric cancer cells. A combination of PKM2 and GLS inhibitors could be therapeutically promising for the treatment of gastric cancer.

[Percutaneous Transhepatic Cholangiodrainage to Alleviate Symptoms of Afferent Loop Obstruction--A Case Report].

The patient, a 78-year-old man, had undergone distal gastrectomy for a gastric ulcer 35 years previously. As melena was observed, he was referred to our department, and was subsequently diagnosed with residual gastric cancer and ascending colon cancer. Peritoneal metastasis of gastric cancer was found, and palliative surgeries, including right hemicolectomy, total gastrectomy, and Roux-en-Y reconstruction were performed. Although postoperative chemotherapy was commenced, side effects led to a decreased performance status (PS), which resulted in the patient shifting to the best supportive care (BSC). Five months after surgery, the patient was urgently transferred to the hospital with upper abdominal pain, and underwent computed tomography (CT) scan. The patient was diagnosed with acute afferent loop obstruction due to peritoneal metastases. It was not possible to perform endoscopic drainage because of the stenosis; therefore, percutaneous transhepatic cholangiodrainage (PTCD) was performed to reduce the pressure in the duodenal afferent loop. Herein, we report on a case of afferent loop obstruction, for which we performed decompression of the afferent loop with PTCD, allowing the patient to continue BSC for approximately 3 months.

[Advanced gastric cancer(Stage IV)leading to perforation during chemotherapy with S-1 plus cisplatin].

A 60-year-old man was diagnosed with advanced gastric cancer(Type 3)with multiple liver and lymph node metastases. The clinical stage was determined to be T3(SS), N2, M1, P0, H1, Stage IV, and a chemotherapy regimen of S-1 plus cisplatin (CDDP)was selected for treatment. During 3 courses of chemotherapy, the patient complained of severe abdominal pain, and an urgent laparotomy was performed with a tentative diagnosis of perforated gastric cancer. Surgical findings revealed a 5-mm perforation in the upper part of the anterior wall of the stomach, from the center of the tumor. Although we detected a metastasis only in S6 of the liver, we decided to perform total gastrectomy, D1 lymphadenectomy, and Roux-en-Y reconstruction. Pathological findings demonstrated that cancer cells were replaced by fibrosis, and tumor response after treatment was determined to be Grade 2. No lymph node metastasis was observed. The patient received chemotherapy with S-1 4 weeks after the operation, without any perioperative complications. The patient is alive 12 months after the operation, without any enlargement of the liver metastasis.

[A case of Stage IV gastric cancer in which a partial response was maintained for four years with multidisciplinary treatment].

The patient was a 63-year-old man with Stage IV gastric cancer (cT3, cNX, cM1[LYN]). After chemotherapy with S-1 plus paclitaxel (PTX), a partial response was achieved, and distal gastrectomy was subsequently performed. During continued chemotherapy with S-1 plus PTX after surgery, enlarged lymph nodes (#16) were observed. Metastasis was detected and treated with radiation therapy. Ten months after the cervical and Virchow lymph node metastases were detected, lymph node dissection was performed. After the second surgery, chemotherapy with S-1 plus cisplatin (CDDP) was selected, but the regimen was changed to S-1 alone because of cerebral infarction. This treatment resulted in the maintenance of a partial response for one year. However, lymph node metastases around the right iliac artery and left cervix subsequently appeared, and lymph node dissection was performed. Since the metastatic lesions remained inside the left parotid gland, radiation therapy to the cervical region was performed again. However, the right inguinal and iliac lymph node metastases enlarged, and we again attempted to treat them with radiation therapy. The patient died due to peritoneal dissemination four years and two months after his first visit.

[Effectiveness of eribulin chemotherapy for squamous cell carcinoma of the breast].

The patient was a 40-year-old woman who was aware of a tumor in her left breast that was gradually increasing in size. Ultrasonography revealed a hypoechoic mass with a skin cyst, approximately 3 cm in size, in the C area of the left breast. Core needle biopsy indicated estrogen receptor (ER) -negative, progesterone receptor (PR) -negative, and human epidermal growth factor receptor 2 (HER2) -negative squamous cell carcinoma. Overall examination did not indicate distant metastasis. A diagnosis of T4bN2aM0, stage IIIB triple-negative left breast cancer was made. Eribulin was administered at a dose of 1.4 mg/m2. The effect of eribulin was considered to be long-term stable disease( long-term SD). The patient did not experience severe adverse events during treatment. After 24 weeks of eribulin treatment, mastectomy of the left breast with axillary lymph node dissection was performed. At present, 1 year after surgery, the patient is alive with no recurrence. We conclude that eribulin chemotherapy is useful for the treatment of patients with squamous cell carcinoma of the breast.

Establishment of a gastric cancer cell line with high microsatellite instability, OCUM-13, derived from Borrmann type-2 primary tumor.

Gastric cancer (GC) with microsatellite instability (MSI) has been reported to be sensitive to immunotherapy, however some of GC cases with MSI remain resistant to immunotherapy. Cancer cell lines showing MSI might be useful for the analysis of mechanisms of immunotherapy, while only a few GC cell lines with MSI are available so far. In this study, we established a unique GC cell line with MSI, OCUM-13, from a primary GC with abundant tumor-infiltrating lymphocytes. MSI assay indicated that OCUM-13 cells as well as the primary tumor showed a band shift in more than 3 of 5 microsatellite loci, suggesting that OCUM-13 did have high MSI. The subcutaneous inoculation of OCUM-13 cells into mice performed tumor formation. Insulin-like growth factor 1 receptor inhibitor decreased the growth of OCUM-13 cells. The newly established cell line with MSI, OCUM-13, might be useful for the analysis of cancer therapy for GC with MSI.

Dipeptidyl Peptidase-4 from Cancer-associated Fibroblasts Stimulates the Proliferation of Scirrhous-type Gastric Cancer Cells.

BACKGROUND/AIM: Cancer-associated fibroblasts (CAFs) may promote the malignancy of human scirrhous gastric cancer (SGC) cells. We conducted the present study to identify novel growth factors from CAFs. MATERIALS AND METHODS: OCUM-12 and 2 CAF cell lines were used. The proliferation of cancer cells was determined by the number of cancer cells or the MTT assay. The growth factor(s) were purified and characterized by the gel filtration chromatography and protein array. RESULTS: The molecular weight of the growth-stimulating factor was estimated to be approximately 66-669 kDa. Protein array of conditioned medium (CM) from CAFs indicated that dipeptidyl peptidase-4 (DPP-4) was one of the growth factors. The addition of CM increased the phosphorylation of C-X-C chemokine receptor 4 (CXCR4). The DPP-4 inhibitor significantly inhibited the growth-stimulating activity of CM. CONCLUSION: DPP-4 from CAFs might be one of the growth-stimulating factors for SGC through CXCR4.

Circulating CEA-positive and EpCAM-negative tumor cells might be a predictive biomarker for recurrence in patients with gastric cancer.

It has been reported that circulating tumor cells (CTCs) are beneficial for predicting tumor stage or treatment response. Although epithelial cell adhesion molecules (EpCAMs) and cytokeratin (CK) have been often used for the identification of CTCs, other tumor markers have not been fully investigated as detecting tools for CTCs. Thus, this study aims to clarify the significance of carcinoembryonic antigen (CEA, CD66e)-positive CTCs in patients with gastric cancer. A total of 150 patients with gastric cancer were enrolled in this study. The mononuclear fraction of peripheral blood was enriched by Ficoll. The number of cells was enumerated depending on the positivity of EpCAM and CEA or CK by flow cytometry. The association of these cells with clinicopathologic characteristics was investigated. The mean age was 70 (range 28-92). The macroscopic type of gastric cancer was classified as 0/1/2/3/4/5 in 59/11/22/38/16/4 patients, respectively. Seventy-one patients (47.3%) were diagnosed with intestinal-type cancer, while 76 patients (50.7%) were diagnosed with the diffuse type. The mean numbers of cells with EpCAM-CK+, EpCAM+CK-, EpCAM+CK+, EpCAM-CEA+, EpCAM+CEA-, and EpCAM+CEA+ were 618, 237, 19.9, 1147, 291, and 7.41, respectively. The number of EpCAM-CEA+cells was significantly higher in patients with stage II-III and IV than in patients with stage I. The 3-year RFS rate in patients with a high number of EpCAM-CEA+cells (>=622) was 57.5%, while it was 79.3% in patients with a low number of EpCAM-CEA+cells (<622) (log-rank p = 0.0079). Thus, we conclude that CEA-positive CTCs will be a clinically beneficial biomarker in patients with gastric cancer.