Keita Uchino

Human Nanog pseudogene8 promotes the proliferation of gastrointestinal cancer cells

There is emerging evidence that human solid tumor cells originate from cancer stem cells (CSCs). In cancer cell lines, tumor-initiating CSCs are mainly found in the side population (SP) that has the capacity to extrude dyes such as Hoechst 33342. We found that Nanog is expressed specifically in SP cells of human gastrointestinal (GI) cancer cells. Nucleotide sequencing revealed that NanogP8 but not Nanog was expressed in GI cancer cells. Transfection of NanogP8 into GI cancer cell lines promoted cell proliferation, while its inhibition by anti-Nanog siRNA suppressed the proliferation. Immunohistochemical staining of primary GI cancer tissues revealed NanogP8 protein to be strongly expressed in 3 out of 60 cases. In these cases, NanogP8 was found especially in an infiltrative part of the tumor, in proliferating cells with Ki67 expression. These data suggest that NanogP8 is involved in GI cancer development in a fraction of patients, in whom it presumably acts by supporting CSC proliferation.

Schedule-dependent synergistic interaction between gemcitabine and oxaliplatin in human gallbladder adenocarcinoma cell lines

To define the most effective combination schedule of gemcitabine and oxaliplatin (L-OHP), we investigated the in-vitro interaction between these drugs in a panel of four human gallbladder adenocarcinoma cell lines (HAG-1, GB-d1, NOZ, and G-415). Cytotoxic activity was determined by the WST-1 assay. Different schedules of the two drugs were compared and evaluated for synergism, additivity, or antagonism with a quantitative method based on the median-effect principle of Chou and Talalay. Cell cycle perturbation and apoptosis were evaluated by flow cytometry. Simultaneous and sequential treatments of gemcitabine followed by L-OHP exhibited synergistic effects in all four cell lines, whereas the reverse sequence largely showed an antagonism. Gemcitabine exclusively arrested cells at the G0/G1 phase, and L-OHP at the G2/M phase, as measured by flow cytometric analyses. Apoptosis was most prominent when cells were treated simultaneously or in a sequence gemcitabine followed by L-OHP, producing apoptosis in treated cells (27–30%). In contrast, the reverse sequence yielded only 6–7% induction of apoptosis, the rate being not significantly different from those induced by each drug singly. Moreover, this sequence dependence was further confirmed by the experiment, which compared the number of HAG-1 cells 7 days after these combination schedules. These findings suggest that the interaction of gemcitabine and L-OHP is highly schedule dependent, with the most efficacious interaction observed in either simultaneous combination or in a sequence combination of gemcitabine followed by L-OHP.

Immunosuppressant therapy successfully improved regorafenib-induced severe hepatic injury in a patient with metastatic gastrointestinal stromal tumor: A case report

A 75-year-old man diagnosed with ileal gastrointestinal tumor with peritoneal dissemination was subjected to salvage treatment with regorafenib at 120 mg/day. Following the initiation of the treatment, liver dysfunction appeared on day 28, and continued to worsen despite termination of the treatment. Since no increase in the levels of serum immunoglobulins of the patient was observed, and negative results were obtained for the analysis of viral markers and autoantibodies, a diagnosis of regorafenib-induced hepatitis was suggested. In consequence, the patient received steroid pulse therapy and continuous administration of prednisolone, without sufficient improvement. Liver biopsy revealed interface hepatitis with prominent plasma cell infiltration, suggesting regorafenib-induced autoimmune hepatitis. The patient was then administered azathioprine and prednisolone, which improved the hepatic injury. The present case represents the first report of successful treatment of regorafenib-induced severe hepatic injury by the use of an immunosuppressant.

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) β 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-PDGFβ 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.

Weight Loss During Initial Chemotherapy Predicts Survival in Patients With Advanced Gastric Cancer

ABSTRACT Background: Patients with advanced gastric cancer (AGC) often suffer weight loss, which can be used to predict prognosis. Few reports have assessed the correlation between weight loss during chemotherapy and survival in patients with AGC. Methods: Fifty-three patients with histologically proven AGC, who started systemic chemotherapy from September 2010 to March 2014, were retrospectively examined for body weight, inflammatory status, and survival. Correlation analyses were performed between weight change and survival. Correlations between weight loss and the patient characteristics were analyzed by stepwise multiple regression analyses. Results: The mean age of the patients was 64.4 years; 64% of the patients were males. Initial chemotherapy included fluoropyrimidine plus cisplatin (62%), fluoropyrimidine alone (26%), and other medications (12%); 72% of the patients exhibited weight loss during the initial therapy. Poorer mean overall survival and mean progression-free survival were observed in patients with weight loss of higher-than-average values than in those with weight loss of lower-than-average values. Serum C-reactive protein levels were significantly correlated with weight loss. Conclusions: Weight loss during initial chemotherapy for AGC may predict survival. Systemic inflammation is suggested to be associated with weight loss.

SAFETY AND TOLERABILITY OF VANDETANIB IN JAPANESE PATIENTS WITH MEDULLARY THYROID CANCER: A PHASE I/II OPEN-LABEL STUDY

OBJECTIVE In a phase III trial, Western patients with medullary thyroid cancer (MTC) treated with the oral multikinase inhibitor vandetanib showed significantly improved progression-free survival (PFS) and objective response rate (ORR) compared with placebo. The biology of MTC and pharmacokinetics (PK) are similar for Japanese and Western patients; therefore, similar clinical benefit is anticipated in the Japanese population. This study evaluated the safety and tolerability of vandetanib in Japanese patients with unresectable locally advanced or metastatic MTC. METHODS This was a phase I/II, open-label, nonrandomized study. Patients received vandetanib (300 mg daily) until objective disease progression. The primary endpoints were safety and tolerability. Secondary endpoints included efficacy and PK. Final data analysis was conducted once all patients with measurable baseline disease had been followed to progression, or for 56 weeks. RESULTS Fourteen patients received vandetanib. All patients experienced at least one adverse event (AE), and 7 patients (50%) experienced grade ≥3 AEs. Common AEs included diarrhea (79%), hypertension (64%), and rash (43%). Four patients reported a total of five serious AEs (SAEs). Eleven patients (79%) had dose interruptions, and 8 patients (57%) had dose reductions. One patient discontinued treatment because of an SAE (interstitial lung disease). No patients met the prespecified criterion for QTc prolongation. The ORR was 38% and PFS at 12 months was 85%. CONCLUSION Safety and efficacy data were comparable to those previously reported, and AEs were generally manageable by standard clinical practice or dose modifications. Overall, vandetanib was considered to be beneficial for Japanese MTC patients. ABBREVIATIONS AE = adverse event CI = confidence interval Css,max = maximum steady-state plasma concentration DCR = disease control rate EGFR = epidermal growth factor receptor ILD = interstitial lung disease MTC = medullary thyroid cancer ORR = objective response rate PFS = progression-free survival PK = pharmacokinetics RECIST = Response Evaluation Criteria in Solid Tumors RET = re-arranged during transfection SAE = serious adverse event VEGFR = vascular endothelial growth factor receptor.

Individualized Dosing of Axitinib Based on First-Dose Area Under the Concentration–Time Curve for Metastatic Renal-Cell Carcinoma

Background Previous studies have revealed that higher exposure of axitinib leads to better prognosis in metastatic renal‐cell carcinoma. We thus assessed individualized dosing of axitinib on the basis of the first‐dose area under the concentration–time curve from 0 to 12 hours (AUC0‐12) for sunitinib‐pretreated metastatic renal‐cell carcinoma patients. Patients and Methods In this prospective single‐arm trial, the starting dose of axitinib was 5 mg twice daily. A series of blood samples were taken at predetermined times after the first dose to calculate AUC0‐12. On day 15 of axitinib administration, the dose was adjusted to ensure ≥ 150 ng·h/mL AUC0‐12 at steady state according to first‐dose AUC0‐12. The primary end point was the 6‐month progression‐free survival rate. Results Twenty‐six Japanese patients were enrolled. The median recommended dose based on the first‐dose AUC0‐12 was 2.5 mg (range, 1‐16 mg) twice daily. The 6‐month progression‐free survival rate for all enrolled patients and per‐protocol set, from which 3 patients were excluded for not adjusting to the recommended dose on day 15, was 84.6% (95% confidence interval, 65.5‐94.1) and 82.6% (95% confidence interval, 61.8‐93.3), respectively. The most common nonhematologic adverse events were hypertension, hand–foot syndrome, fatigue, and decreased appetite. Eighteen patients (75%) developed grade 3 hypertension; however, actual blood pressure could be controlled using antihypertensive agents. Other adverse events were manageable during the protocol treatment. Conclusion Individualized dosing of axitinib based on the first‐dose AUC0‐12 might have promising efficacy and manageable toxicity. Micro‐Abstract Individualized dosing of axitinib based on drug exposure remains unknown. In this study we evaluated the efficacy and safety of the recommended axitinib dose on the basis of the first‐dose area under the concentration–time curve from 0 to 12 hours in metastatic renal‐cell carcinoma. Adjusting to the recommended dose lead to promising efficacy and manageable toxicity. The current study provides novel information to develop individualized axitinib treatment.

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.

Predictive value of the modified Glasgow Prognostic Score for the therapeutic effects of molecular‑targeted drugs on advanced renal cell carcinoma

Inflammation is considered to be a prognostic factor for renal cell carcinoma (RCC). An inflammation-based prognostic score (modified Glasgow Prognostic Score; mGPS) is widely used for preoperative patients; however, little information is available regarding its prognostic value in patients with RCC treated with molecular-targeted drugs. A total of 32 advanced and recurrent RCC patients initially treated with molecular-targeted drugs from October, 2009 to August, 2015 were retrospectively investigated. Information on patient characteristics prior to treatment initiation and the clinical course were retrieved from clinical records. The correlation between survival and patient variables was analyzed. Survival was compared among patient groups according to the mGPS score. The median patient age was 66 years. The percentage of patients with an Eastern Cooperative Oncology Group performance status of 0 or 1 was 87.5, and 65.6% of the RCCs were clear cell carcinomas. A Memorial Sloan-Kettering Cancer Center index of good or intermediate was determined for 75% of the patients. Sunitinib, pazopanib or sorafenib was administered to 56, 22 and 13% of the cases, respectively. An mGPS score of 0, 1 and 2 was calculated for 66, 9 and 25% of the cases, respectively. Patients in the mGPS low group (score 0) exhibited significantly better progression-free survival (PFS) and overall survival (OS) compared with patients in the mGPS high group (score 1 or 2) (median PFS, 307 vs. 70 days and median OS, 1,081 vs. 140 days, respectively). In conclusion, inflammatory status as assessed by the mGPS score was closely associated with the prognosis of RCC patients treated with molecular-targeted therapy.

Early tumor shrinkage indicates a favorable response to bevacizumab-based first-line chemotherapy for metastatic colorectal cancer

A close correlation between early tumor shrinkage (ETS) and overall survival (OS) has been shown in antiepidermal growth factor receptor antibody-based chemotherapies for metastatic colorectal cancer (mCRC), but the clinical impact of ETS in bevacizumab-based chemotherapy has not been adequately clarified. Clinical data of mCRC patients who started initial chemotherapy without antiepidermal growth factor receptor antibody from 2005 to 2010 were retrospectively evaluated. The relative change in tumor size after 8 weeks of chemotherapy expected from the first image assessment [estimated ETS (EETS)] and the relative change in the tumor size at the nadir compared with the baseline [depth of response (DPR)] were examined. Seventy-three patients were enrolled and 61 patients were evaluable for survival by simple regression analysis. Bevacizumab-based chemotherapies were administered to 40 (66%) patients. The median EETS, DPR, progression-free survival, and OS were 16.1%, 27.2%, 8.0 months, and 19.5 months, respectively. Progression-free survival showed a positive correlation with OS (R2=0.429), whereas EETS and DPR were less correlated with OS (R2=0.0682, 0.186). EETS was well correlated with DPR (R2=0.659). Patients with EETS greater than 16.12% were predicted to achieve tumor shrinkage of more than 30% at the maximum response. EETS in bevacizumab-treated mCRC showed a close correlation with DPR, which suggested that EETS might be useful, indicating a favorable response in treatment with bevacizumab-based chemotherapy.