RHAMM marks proliferative subpopulation of human colorectal cancer stem cells.

The cancer stem cell (CSC) theory features typically rare self-renewing subpopulations that reconstitute the heterogeneous tumor. Identification of molecules that characterize the features of CSCs is a key imperative for further understanding tumor heterogeneity and for the development of novel therapeutic strategies. However, the use of conventional markers of CSCs is still insufficient for the isolation of bona fide CSCs. We investigated organoids that are miniature forms of tumor tissues by reconstructing cellular diversity to identify specific markers to characterize CSCs in heterogeneous tumors. Here, we report that the receptor for hyaluronan-mediated motility (RHAMM) expresses in a subpopulation of CD44+ conventional human colorectal CSC fraction. Single-cell transcriptomics of organoids highlighted RHAMM-positive proliferative cells that revealed distinct characteristics among the various cell types. Prospectively isolated RHAMM+CD44+ cells from the human colorectal cancer tissues showed highly proliferative characteristics with a self-renewal ability in comparison with the other cancer cells. Furthermore, inhibition of RHAMM strongly suppressed organoid formation in vitro and inhibited tumor growth in vivo. Our findings suggest that RHAMM is a potential therapeutic target because it is a specific marker of the proliferative subpopulation within the conventional CSC fraction.

Multicenter Retrospective Analysis of Original versus Modified FOLFIRINOX in Metastatic Pancreatic Cancer: Results of the NAPOLEON Study.

INTRODUCTION: Original FOLFIRINOX (oFFX) is more toxic than other regimens for patients with metastatic pancreatic cancer (mPC); therefore, a modified FFX (mFFX) regimen with a reduced dosage has been used in Japanese clinical practice. However, very few studies have compared these two regimens. METHODS: This study was conducted as part of a multicenter retrospective study of 318 patients with mPC across 14 centers in Japan (NAPOLEON study). To control for potential bias and confounders, we conducted a propensity score-adjusted analysis of patient characteristics and clinical outcomes. RESULTS: oFFX and mFFX were administered to 48 and 54 patients. More patients with younger age and poorer performance status were included in the oFFX group. The overall survival (OS; median, 11.6 vs. 11.3 months; hazard ratio [HR], 0.91; 95% confidence interval [CI], 0.60-1.40; p = 0.67), progression-free survival (PFS) (median, 6.3 vs. 5.7 months; HR, 0.85; 95% CI, 0.56-1.28; p = 0.44), and overall response rate (29 vs. 26%, p = 0.71) were not significantly different for the oFFX and mFFX groups. Thrombopenia and liver dysfunction were significantly more frequent with oFFX than with mFFX. The median received dose intensity of CPT-11 was higher with oFFX than with mFFX (299 vs. 270 mg/m2/week, p < 0.01). The propensity score-adjusted analysis revealed no statistically significant differences in OS and PFS between the two groups. CONCLUSION: In our data, there was no significant difference in efficacy between mFFX and oFFX, and mFFX has fewer adverse events.

RNA N6-methyladenosine demethylase FTO regulates PD-L1 expression in colon cancer cells.

Fat mass and obesity-associated protein (FTO) is an enzyme that demethylates N6-methyladenosine (m6A), the most abundant RNA modifications in a cell. The upregulated expression of FTO promotes the progression of various types of cancer by modulating cell-intrinsic genes which relate to malignant potential. However, the impact of FTO on the expression of immune-checkpoint molecules in the tumor cells, which are important for immune escape, has not been well understood. We examined the relevance of FTO to programmed cell death-ligand 1 (PD-L1) expression in colon cancer cells. HCT-116 cells showed high expression of both FTO and PD-L1 proteins. The knockdown of FTO by small interfering RNA decreased mRNA and protein levels of PD-L1 in HCT-116 cells. To elucidate the underlying mechanism by which FTO regulates the expression of PD-L1, we depleted FTO in HCT-116 in the presence of IFN-γ, which is a major stimulus to upregulate PD-L1 expression. Depletion of FTO reduced PD-L1 expression in an IFN-γ signaling-independent manner. RNA immunoprecipitation assay revealed the m6A modification of the PD-L1 mRNA and the binding of FTO to the PD-L1 mRNA in HCT-116. Taken together, our results indicated that FTO could regulate PD-L1 expression in colon cancer cells and provides new insights into the regulation of PD-L1 expression by RNA modification.

Epithelial-mesenchymal transition is activated in CD44-positive malignant ascites tumor cells of gastrointestinal cancer.

Disseminated cancer cells in malignant ascites possess unique properties that differ from primary tumors. However, the biological features of ascites tumor cells (ATC) have not been fully investigated. By analyzing ascites fluid from 65 gastrointestinal cancer patients, the distinguishing characteristics of ATC were identified. High frequency of CD44+ cells was observed in ATC using flow cytometry (n = 48). Multiplex quantitative PCR (n = 15) showed higher gene expression of epithelial-mesenchymal transition (EMT)-related genes and transforming growth factor beta (TGF-beta)-related genes in ATC than in the primary tissues. Immunohistochemistry (n = 10) showed that ATC also had much higher expression of phosphorylated SMAD2 than that in the corresponding primary tissues. TGF-beta 1 was detected in all cases of malignant ascites by enzyme-linked immunoassay (n = 38), suggesting the possible interaction of ATC and the ascites microenvironment. In vitro experiments revealed that these ATC properties were maintained by TGF-beta 1 in cultured ATC(n = 3). Here, we showed that ATCrevealed high frequencies of CD44 and possessed distinct EMT features from primary tissues that were mainly maintained by TGF-beta 1 in the ascites.

PD-1+ TIM-3+ T cells in malignant ascites predict prognosis of gastrointestinal cancer.

The liquid biopsy of ascites fluid could be an excellent source of tumor and microenvironment for the study of prognostic biomarkers because of its accessibility. Tumor-infiltrating lymphocytes (TILs) can predict prognosis in multiple malignancies, including the response to immune checkpoint inhibitors, a breakthrough cancer therapy. However, TILs' profiles from malignant ascites have not been extensively studied. Using flow cytometric analysis, we quantified the proportion of exhausted T cells and memory/naive/effector T-cell subsets, among the CD4+ and CD8+ T-cell populations of paired TILs and peripheral blood T cell samples (n = 22). The correlation between CD4+ and CD8+ subset profiles suggested that the combined analysis of CD4+ and CD8+ cells in malignant ascites was clinically significant. We found that cells positive for the exhaustion markers programmed cell death-1 (PD-1), and T-cell immunoglobulin and mucin domain 3 (TIM-3), and cells coexpressing PD-1 and TIM-3 abundantly exist among malignant ascites TILs. Furthermore, patients with high frequency of PD-1+ TIM-3+ cells among the CD4+ and CD8+ T-cell population showed worse clinical outcome in multivariate analysis (n = 27). We propose that exhausted ascites TILs represent a clinically significant prognostic biomarker in advanced gastrointestinal cancer and represent an important target for immune checkpoint inhibitors.

Pulmonary tumor embolism from breast cancer diagnosed by selective aspiration cytology using a Swan-Ganz catheter.

We describe a case of pulmonary tumor embolism (PTE) from breast cancer diagnosed by selective aspiration cytology using a Swan-Ganz catheter. A 60-year-old woman was referred to Hamanomachi Hospital because of increased levels of tumor markers. The patient complained only of slight exertional dyspnea and a dry cough. Due to breast cancer, she had undergone a mastectomy followed by radiation and chemotherapy one year earlier. Positron emission tomography scanning with CT images revealed no evidence of malignancy. Repeated chest CT images showed emerging wedge-shaped nodules in the subpleural zones of the left lower lobe with diffuse ground-glass opacities in the bilateral lower lobes. The D-dimer level was negative. Pulmonary perfusion scintigraphy showed multiple small wedge-shaped defect areas on the peripheral sides of the bilateral lungs. Suspecting PTE, we performed selective aspiration cytology from the left pulmonary arteries. Cancer cells were detected from selected branches of left A8 and A9. Morphology and immunostaining led to a final diagnosis of PTE of recurrent breast cancer. Pulmonary embolism of cancer is a progressive, fatal condition with challenging diagnosis. Selective aspiration cytology with a Swan-Ganz catheter is a useful, less invasive option in patients with suspected PTE.

Thrombocytopenia Caused by Dexamethasone in a Patient with Colorectal Cancer.

Drug-induced immune thrombocytopenia (DITP) is an important cause of thrombocytopenia. A 73-year-old man with relapsed rectal carcinoma received S-1, oxaliplatin and bevacizumab combination therapy (SOX+Bev). Dexamethasone was administered as an antiemetic prophylaxis. On day 2 of the first cycle, thrombocytopenia (8,000/µL) was observed. We sequentially omitted any drugs suspected to possibly induce thrombocytopenia and confirmed dexamethasone as the cause of thrombocytopenia. DITP induced by synthetic corticosteroids is very rare and this is the first case report of DITP induced by dexamethasone. Although rare, DITP due to synthetic corticosteroids including dexamethasone should be a differential diagnosis among patients receiving synthetic corticosteroids with thrombocytopenia.

Successful chemotherapeutic treatment for metastatic littoral cell angioma: A case report.

RATIONALE: Metastatic littoral cell angioma (LCA) is extremely rare. No standard therapeutic strategy has been established, and the impact of chemotherapy has not yet been evaluated. PATIENT CONCERNS: A 61-year-old woman was admitted because of bicytopenia. She had a splenectomy for LCA of the spleen 10 years earlier. Bone marrow aspiration was normal, and a computed tomography (CT) scan showed hepatomegaly with multiple liver tumors. DIAGNOSES: Liver biopsy samples showed macrophage-like cell infiltration in the hepatic sinusoids. Metastatic LCA was diagnosed based on immunohistochemistry, imaging tests, and the clinical course. INTERVENTIONS: Immunosuppressive agents, such as prednisolone and cyclosporine, were ineffective. Next, cytotoxic agents, such as etoposide, paclitaxel, and vincristine, were administered. OUTCOMES: Cytotoxic agents showed a prominent effect against LCA. CT showed improvement of the hepatomegaly, and fluoro-deoxyglucose (FDG) uptake decreased markedly at a follow-up FDG- positron emission tomography (PET) scan. LESSONS: Chemotherapeutic treatment based on hemophagocytic syndrome or angiosarcoma might have anti-tumor activity against metastatic LCA. Analysis of the molecular characteristics of this tumor is needed to develop better treatment options.

Pancreatic acinar cell carcinoma presenting with panniculitis, successfully treated with FOLFIRINOX: A case report.

Pancreatic acinar cell carcinoma (PACC) is a rare tumor of the exocrine pancreas, representing only 1% of all pancreatic malignancies. A 50-year-old man presented with edema of the thumb joints bilaterally, followed by an appearance of masses in the bilateral lower extremities and fever (38°C). The masses were diagnosed as panniculitis by skin biopsy, and multiple intraperitoneal masses were incidentally detected on pelvic magnetic resonance imaging performed to investigate the leg abnormalities. The patient was referred to the Kyushu University Hospital for further investigation, and fluorodeoxyglucose-positron emission tomography/computed tomography (CT) revealed high-uptake tumors in the pancreatic tail, in the periphery of the liver, and in the pelvis. Laboratory examinations revealed high serum concentrations of pancreatic exocrine enzymes, such as lipase, trypsin, elastase 1 and pancreatic phospholipase A2. Histological examination of a bioptic specimen obtained from a hepatic lesion revealed proliferation of atypical cells arranged in a tubular or glandular pattern. Immunohistochemical staining revealed that the atypical cells were positive for cytokeratin (CK)7, CK19 and lipase, but negative for CK20 and thyroid transcription factor-1, leading to a final diagnosis of acinar cell carcinoma of the pancreatic tail (T4bN0M1, stage IV according to the 7th edition of the TNM Classification of Malignant Tumors). Combined chemotherapy with oxaliplatin, irinotecan and fluorouracil (FOLFIRINOX) was administered and fever was soon alleviated. The serum levels of lipase also declined and panniculitis completely resolved. As of the start of the 8th course of chemotherapy, the levels of the pancreatic exocrine enzymes were within normal ranges and CT revealed partial response. Therefore, the severe lipase hypersecretion syndrome was well controlled by the FOLFIRINOX regimen and shrinkage of the mass was also achieved. Thus, the FOLFIRINOX regimen may represent an effective treatment option for advanced PACC.

Programmed death-ligand 1 expression is associated with fibrosarcomatous transformation of dermatofibrosarcoma protuberans.

Dermatofibrosarcoma protuberans (DFSP) is a locally invading tumor, characterized by the presence of the collagen type I α 1 (COL1A1)-platelet-derived growth factor (PDGF) ß fusion gene. We herein report the case of a 31-year-old man with a history of resection of an abdominal wall DFSP. The patient presented with chest pain and a computed tomography scan revealed a large mass in the posterior mediastinum and another mass in the right lung. The mediastinal mass was a sarcomatous lesion expressing the COL1A1-PDGFß fusion gene, suggesting that it represented a metastasis of the DFSP following fibrosarcomatous (FS) transformation. Following resection of the mediastinal metastasis and subsequent radiotherapy, the mass in the right lung was also resected. Due to the emergence of pleural and pancreatic tail metastases, the patient was treated with a combination therapy of adriamycin and ifosfamide. After five courses, the disease progressed and the patient was subsequently treated with pazopanib for ~2 months until further progression. Three years after the diagnosis of the mediastinal metastasis of DFSP, the patient was referred to another hospital for palliative care. The expression of programmed cell death 1 ligand (PD-L1) in the primary and metastatic tumors was investigated: PD-L1 expression was detected in the metastasis but not in the primary tumor. Given that the metastatic tumor exhibited FS transformation (DFSP-FS), PD-L1 expression may be induced by FS transformation, contributing to the metastasis through escape from immune surveillance. Further investigation of the PD-L1 pathway in DFSP and DFSP-FS in primary as well as metastatic sites is required to evaluate the clinical efficacy of therapies targeting the PD-L1 signaling cascade.

Cardiac metastasis of squamous cell carcinoma of the thyroid gland with severe disseminated intravascular coagulation: A case report.

Distant metastasis of primary squamous cell carcinoma (SCC) of the thyroid gland is rare and, to the best of our knowledge, cardiac metastasis has not been reported to date. A 57-year-old man underwent surgery and adjuvant chemoradiotherapy for stage IVA SCC of the thyroid gland. After 3 months, the patient was admitted to the Kyushu University Hospital (Fukuoka, Japan) with subcutaneous hematomas of the left thigh and lower leg, and he was diagnosed with cardiac and mediastinal lymph node metastases of SCC of the thyroid gland with severe disseminated intravascular coagulation (DIC). Echocardiography revealed a mass, 52 mm in greatest diameter, protruding from the interventricular septum towards the right ventricle. Weekly administration of paclitaxel and concurrent irradiation of the cardiac and lymph node metastases were performed. Eighteen days after the initiation of chemoradiotherapy, the DIC and hematomas had significantly improved, and the cardiac metastasis was stable. However, 2 months after admission, the patient developed dyspnea and multiple nodular shadows appeared to be spreading in the subpleura of the lungs bilaterally, which were initially suspected to be pulmonary tumor embolisms. Prednisolone and subsequent administration of lenvatinib were not effective and the patient succumbed to respiratory failure. Severe DIC caused by extremely rare cardiac metastasis of SCC of the thyroid gland was effectively controlled by chemoradiotherapy. However, intensive local control appears to be required for this condition.

Systemic chemotherapy with pronounced efficacy and neutropenia in a granulocyte-colony stimulating factor-producing advanced gastric neuroendocrine carcinoma.

An advanced granulocyte-colony stimulating factor (G-CSF)-producing tumor is rare, and it exhibits leukocytosis in association with high serum G-CSF levels. A 67-year-old male with a 1-month history of bloody emesis and black stools was revealed to exhibit leukocytosis, anemia and a high serum concentration of G-CSF. During a gastrointestinal endoscopy, an ulcerating tumor was identified in the stomach. Computed tomography and a fluorodeoxyglucose-positron emission tomography scan demonstrated direct invasion of the gastric tumor into the transverse colon, regional lymphadenopathy, lung nodules and diffuse high uptake of FDG in bone marrow. The histological diagnosis was a G-CSF-producing neuroendocrine carcinoma (NEC) (tumor 4b, node 2, metastasis 1, pulmonary, clinical stage IV). Systemic chemotherapy consisting of cisplatin and irinotecan was started. Common terminology criteria of adverse events grade 3 tumor lysis syndrome and gastric penetration appeared. Grade 4 neutropenia lasted for 10 days despite intensive G-CSF administration. Prominent shrinkage of the primary and the metastatic tumors was observed subsequent to 3 cycles of chemotherapy. Total gastrectomy and resection of the transverse colon were subsequently performed. Systemic chemotherapy was effective for a G-CSF-producing advanced gastric NEC with careful monitoring and appropriate supportive care for severe adverse events.

Bi-cytopenia possibly induced by anti-PD-1 antibody for primary malignant melanoma of the esophagus: A case report.

BACKGROUND: Anti-programmed cell death 1 antibody nivolumab is a promising agent for various cancers. Immune-related adverse events are recognized; however, bi-cytopenia with nivolumab has not been reported. CASE PRESENTATION: A 73-year-old man was diagnosed with advanced primary malignant melanoma of the esophagus with liver, lung, and lymph node metastases. Previous therapies including dacarbazine and radiation of 39 Gy to the esophageal region were performed, but the liver metastases deteriorated. The patient was then administered nivolumab (2 mg/kg, every 3 weeks). After 3 cycles, the esophageal tumor and lymph nodes showed marked reductions in size, the lung metastases disappeared, and the liver metastases shrank partially. The treatment continued with 7 cycles for 4 months. However, severe anemia and thrombocytopenia appeared in the 6th cycle, and intermittent blood transfusions were required. The patient received high-dose intravenous methylprednisolone therapy for bi-cytopenia, but it was ineffective. Seven months after the initiation of nivolumab, the patient died of tumor. Although the mechanisms of bi-cytopenia were unclear, it could have been induced by nivolumab. CONCLUSION: The present case shows a rare but serious life-threatening bi-cytopenia possibly associated with nivolumab and suggests the importance of awareness of hematological adverse events during nivolumab therapy.