Long-term Survival with a Rare Advanced Primary Gastrointestinal Malignant Melanoma Treated with Laparoscopic Surgery/Immune Checkpoint Inhibitor

Targeted therapies for malignant melanoma have improved patients’ prognoses. A primary gastrointestinal malignant melanoma is very rare, with no standard treatment strategy. We treated a 78-year-old Japanese female with advanced primary gastrointestinal melanoma of the descending colon and gallbladder. We administered a multidisciplinary treatment: surgical resection of the descending colon and gallbladder tumors, resection of the metastatic lymph nodes behind the pancreas head, and immune checkpoint antibody-blockade therapy (nivolumab) for ~4 years. PET/CT demonstrated no recurrent lesion for > 3 years. Multidisciplinary therapies (e.g., surgery, chemotherapy, radiotherapy, target therapy, and immune checkpoint antibody-blockade therapy) can successfully treat primary gastrointestinal malignant melanoma

Hepatocyte growth factor reduces susceptibility to an irreversible epidermal growth factor receptor inhibitor in EGFR-T790M mutant lung cancer

金沢大学附属病院がん高度先進治療センターPurpose: The secondary T790M mutation in epidermal growth factor receptor (EGFR) is the most frequent cause of acquired resistance to the reversible EGFR tyrosine kinase inhibitors (EGFR-TKI), gefitinib and erlotinib, in lung cancer. Irreversible EGFR-TKIs are expected to overcome the reversible EGFR-TKI resistance of lung cancer harboring T790M mutation in EGFR. However, it is clear that resistance may also develop to this class of inhibitors. We showed previously that hepatocyte growth factor (HGF) induced gefitinib resistance of lung cancer harboring EGFR-activating mutations. Here, we investigated whether HGF induced resistance to the irreversible EGFR-TKI, CL-387,785, in lung cancer cells (H1975) harboring both L858R activating mutation and T790M secondary mutation in EGFR. Experimental Design: CL-387,785 sensitivity and signal transduction in H1975 cells were examined in the presence or absence of HGF or HGF-producing fibroblasts with or without HGF-MET inhibitors. Results: HGF reduced susceptibility to CL-387,785 in H1975 cells. Western blotting and small interfering RNA analyses indicated that HGF-induced hyposensitivity was mediated by the MET/phosphoinositide 3-kinase/Akt signaling pathway independent of EGFR, ErbB2, ErbB3, and ErbB4. Hyposensitivity of H1975 cells to CL-387,785 was also induced by coculture with high-level HGF-producing lung fibroblasts. The hyposensitivity was abrogated by treatment with anti-HGF neutralizing antibody, HGF antagonist NK4, or MET-TKI. Conclusions: We showed HGF-mediated hyposensitivity as a novel mechanism of resistance to irreversible EGFR-TKIs. It will be clinically valuable to investigate the involvement of HGF-MET-mediated signaling in de novo and acquired resistance to irreversible EGFR-TKIs in lung cancer harboring T790M mutation in EGFR. ©2010 AACR

Principle and clinical usefulness of the infrared fluorescence endoscopy

Since there is no infrared fluorescence materials in the living body, infrared fluorescence labeling materials are very useful for making a diagnosis of a micro cancer. We have developed an infrared fluorescence endoscope (IRFE) and indocyanin green (ICG)-derivative as infrared fluorescence labeling materials to evaluate gastrointestinal neoplastic lesions. The study aims were to apply an IRFE and to demonstrate its usefulness in detecting cancerous tissue using an antibody coupled with ICG-derivative. IRFE consisted of an infrared endoscope equipped with excitation (710-790nm) and barrier (810-920nm) filters and an intensified CCD camera. We have developed ICG N-hydroxy sulfo succinimide ester (ICG-sulfo-OSu) and 3-ICG-acyl-1, 3-thiazolidine-2-thione (ICG-ATT) as an infrared fluorescent-labeling reagent. ICG-derivative-labeled mouse anti-human carcinoembryonic antigen (CEA)antibodyandMUC1 antibody were employed in this study. Moreover, we examined the ability of a reinforcement agent, octylglucoside, to intensity fluorescence from the labeled antibody. Biopsy specimens of gastric cancer were stained with anti-CEA antibody by the avidin-biotinylated peroxidase complex method. Among the positive specimens, freshly resected stomach from three cases were used for the infrared (IR) imaging analysis. The incubation of freshly resected stomach specimens with ICG-anti-CEA antibody-complex resulted in positive staining of the tumor sites by IRFE, and the IR fluorescent images correlated well with the tumor sites. The immunohistochemical studies suggested that the intensity of IR fluorescence of ICG-ATT-MUC1was stronger than that of ICG-sulfo-OSu. In tumor sections, the reinforcement agent intensified fluorescence, ever at low antibody concentrations. Therefore, we conclude that an anti-CEA (and/orMUC1) antibody with affinity for cancerous lesions and labeled with ICG-derivative can be imaged with this IRFE. Specific antibodies tagged with ICG-derivative with the reinforcement agent can label cancer cells and generate a strong enough fluorescent signal to detect small cancers when examined with an IR fluorescence endoscope

Lysophosphatidic acid stimulates the proliferation and motility of malignant pleural mesothelioma cells through lysophosphatidic acid receptors, LPA1 and LPA2

金沢大学がん研究所分子標的がん医療研究開発センターLysophosphatidic acid (LPA) is one of the simplest natural phospholipids. This phospholipid is recognized as an extracellular potent lipid mediator with diverse effects on various cells. Although LPA is shown to stimulate proliferation and motility via LPA receptors, LPA1 and LPA2, in several cancer cell lines, the role of LPA and LPA receptors for malignant pleural mesothelioma (MPM) has been unknown. MPM is an aggressive malignancy with a poor prognosis and the incidence is increasing and is expected to increase further for another 10-20 years worldwide. Therefore, the development of novel effective therapies is needed urgently. In this study, we investigated the effect of LPA on the proliferation and motility of MPM cells. We found that all 12 cell lines and four clinical samples of MPM expressed LPA1, and some of them expressed LPA2, LPA3, LPA4 and LPA5. LPA stimulated the proliferation and motility of MPM cells in a dose-dependent manner. Moreover, LPA-induced proliferation was inhibited by Ki16425, an inhibitor of LPA1, and small interfering RNA against LPA1, but not LPA2. Interestingly, LPA-induced motility was inhibited by small interfering RNA against LPA2, but not LPA1, unlike a number of previous reports. These results indicate that LPA is a critical factor on proliferation though LPA1, and on motility though LPA2 in MPM cells. Therefore, LPA and LPA receptors, LPA2 as well as LPA1, represent potential therapeutic targets for patients with MPM. © 2008 Japanese Cancer Association

RNA editing facilitates the enhanced production of neoantigens during the simultaneous administration of oxaliplatin and radiotherapy in colorectal cancer

Most cases of colorectal cancers (CRCs) are microsatellite stable (MSS), which frequently demonstrate lower response rates to immune checkpoint inhibitors (ICIs). RNA editing produces neoantigens by altering amino acid sequences. In this study, RNA editing was induced artificially by chemoradiation therapy (CRT) to generate neoantigens in MSS CRCs. Altogether, 543 CRC specimens were systematically analyzed, and the expression pattern of ADAR1 was investigated. In vitro and in vivo experiments were also performed. The RNA editing enzyme ADAR1 was upregulated in microsatellite instability-high CRCs, leading to their high affinity for ICIs. Although ADAR1 expression was low in MSS CRC, CRT including oxaliplatin (OX) treatment upregulated RNA editing levels by inducing ADAR1. Immunohistochemistry analyses showed the upregulation of ADAR1 in patients with CRC treated with CAPDX (capecitabine +OX) radiation therapy relative to ADAR1 expression in patients with CRC treated only by surgery (p <0.001). Compared with other regimens, CRT with OX effectively induced RNA editing in MSS CRC cell lines (HT29 and Caco2, p <0.001) via the induction of type 1 interferon-triggered ADAR1 expression. CRT with OX promoted the RNA editing of cyclin I, a neoantigen candidate. Neoantigens can be artificially induced by RNA editing via an OX-CRT regimen. CRT can promote proteomic diversity via RNA editing

ADAR1 is a promising risk stratification biomarker of remnant liver recurrence after hepatic metastasectomy for colorectal cancer

Adenosine-to-inosine RNA editing is a process mediated by adenosine deaminases that act on the RNA (ADAR) gene family. It has been discovered recently as an epigenetic modification dysregulated in human cancers. However, the clinical significance of RNA editing in patients with liver metastasis from colorectal cancer (CRC) remains unclear. The current study aimed to systematically and comprehensively investigate the significance of adenosine deaminase acting on RNA 1 (ADAR1) expression status in 83 liver metastatic tissue samples collected from 36 patients with CRC. The ADAR1 expression level was significantly elevated in liver metastatic tissue samples obtained from patients with right-sided, synchronous, or RAS mutant-type CRC. ADAR1-high liver metastasis was significantly correlated with remnant liver recurrence after hepatic metastasectomy. A high ADAR1 expression was a predictive factor of remnant liver recurrence (area under the curve = 0.72). Results showed that the ADAR1 expression level could be a clinically relevant predictive indicator of remnant liver recurrence. Patients with liver metastases who have a high ADAR1 expression requires adjuvant chemotherapy after hepatic metastasectomy

Therapeutic activity of glycoengineered anti-GM2 antibodies against malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a rare and highly aggressive neoplasm that arises from the pleural, pericardial, or peritoneal lining. Although surgery, chemotherapy, radiotherapy, and combinations of these therapies are used to treat MPM, the median survival of such patients is dismal. Therefore, there is a compelling need to develop novel therapeutics with different modes of action. Ganglioside GM2 is a glycolipid that has been shown to be overexpressed in various types of cancer. However, there are no published reports regarding the use of GM2 as a potential therapeutic target in cases of MPM. In this study, we evaluated the efficacy of the anti-GM2 antibody BIW-8962 as an anti-MPM therapeutic using in vitro and in vivo assays. Consequently, the GM2 expression in the MPM cell lines was confirmed using flow cytometry. In addition, eight of 11 cell lines were GM2-positive (73%), although the GM2 expression was variable. BIW-8962 showed a significant antibody-dependent cellular cytotoxicity activity against the GM2-expressing MPM cell line MSTO-211H, the effect of which depended on the antibody concentration and effector/target ratio. In an in vivo orthotropic mouse model using MSTO-211H cells, BIW-8962 significantly decreased the incidence and size of tumors. Additionally, the GM2 expression was confirmed in the MPM clinical specimens. Fifty-eight percent of the MPM tumors were positive for GM2, with individual variation in the intensity and frequency of staining. These data suggest that anti-GM2 antibodies may become a therapeutic option for MPM patients. In this study, the anti-GM2 antibody BIW-8962 first showed a significant ADCC activity against malignant pleural mesothelioma (MPM) cell line and therapeutic activity in an in vivo orthotropic mouse model using the cell line. Additionally, the GM2 expression was confirmed in the MPM clinical specimens. These data suggest that anti-GM2 antibodies may become a therapeutic option for MPM patients. © 2014 The Authors. Cancer Science published by Wiley Publishing Asia Pty Ltd on behalf of Japanese Cancer Association

Akt kinase-interacting protein1, a novel therapeutic target for lung cancer with EGFR-activating and gatekeeper mutations

Despite initial dramatic response, epidermal growth factor receptor (EGFR) mutant lung cancer patients always acquire resistance to EGFR-tyrosine kinase inhibitors (TKIs). Gatekeeper T790M mutation in EGFR is the most prevalent genetic alteration underlying acquired resistance to EGFR-TKI, and EGFR mutant lung cancer cells are reported to be addictive to EGFR/Akt signaling even after acquired T790M mutation. Here, we focused on Akt kinase-interacting protein1 (Aki1), a scaffold protein of PI3K (phosphoinositide 3-kinase)/PDK1 (3-phosphoinositide-dependent protein kinase)/Akt that determines receptor signal selectivity for non-mutated EGFR, and assessed its role in EGFR mutant lung cancer with or without gatekeeper T790M mutation. Cell line-based assays showed that Aki1 constitutively associates with mutant EGFR in lung cancer cells with (H1975) or without (PC-9 and HCC827) T790M gatekeeper mutation. Silencing of Aki1 induced apoptosis of EGFR mutant lung cancer cells. Treatment with Aki1 siRNA dramatically inhibited growth of H1975 cells in a xenograft model. Moreover, silencing of Aki1 further potentiated growth inhibitory effect of new generation EGFR-TKIs against H1975 cells in vitro. Aki1 was frequently expressed in tumor cells of EGFR mutant lung cancer patients (53/56 cases), including those with acquired resistance to EGFR-TKI treatment (7/7 cases). Our data suggest that Aki1 may be a critical mediator of survival signaling from mutant EGFR to Akt, and may therefore be an ideal target for EGFR mutant lung cancer patients, especially those with acquired EGFR-TKI resistance due to EGFR T790M gatekeeper mutation.Oncogene advance online publication, 8 October 2012; doi:10.1038/onc.2012.446.In Press → 発行後6か月より全文を公開

A Multicenter Phase II Study of Adjuvant Chemotherapy With Oral Fluoropyrimidine S-1 for Non–Small-Cell Lung Cancer: High Completion and Survival Rates

Background: Oral adjuvant chemotherapy without hospitalization might reduce the physiological and psychological burden on patients if effectiveness could be guaranteed. We conducted a multicenter feasibility study using S-1, an oral derivative of 5-fluorouracil, as postoperative adjuvant chemotherapy in patients with curatively resected pathologically stage IB-IIIA non-small-cell lung cancer. Patients and Methods: Adjuvant chemotherapy comprised 8 courses (4-week administration, 2-week withdrawal) of S-1 at 80-120 mg per day. Fifty-one patients from 7 institutions were enrolled in this pilot study, from June 2005 to March 2007. The primary end point was the completion rate of scheduled adjuvant chemotherapy. Secondary end points were the incidence and grade of adverse reactions. Results: Fifty patients were eligible. The completion rate for the planned 8 courses of S-1 administration was 72.0% (36 patients). Total percentage administration amount was 71.1%. Grade 3 adverse reactions such as neutropenia (4.0%), anorexia (4.0%), thrombopenia (2.0%), anemia (2.0%), elevated total bilirubin (2.0%), hypokalemia (2.0%), nausea (2.0%), and diarrhea (2.0%) were observed, but no grade 4 adverse effects were encountered. Overall and relapse-free survival rates at 3 years were 87.7% and 69.4%, respectively. Conclusions: Postoperative 1-year administration of S-1 seems feasible as oral adjuvant chemotherapy for lung cancer. The oral formulation and low incidence of adverse reactions permit treatment on an outpatient basis. The present study would be reasonable to follow up with a properly powered phase III trial

Hospital and clinic cooperation for the treatment of rheumatoid arthritis in Okayama Prefecture, Japan

Objective: To survey the current status and problems of cooperation between clinics and hospitals in Okayama Prefecture, Japan for the treatment of rheumatoid arthritis (RA). 　Methods: We distributed a questionnaire to 300 of the 983 Okayama Prefecture clinics that had either an internal medicine or orthopedic surgery department, from December 2013 to February 2014. The questionnaire covered practice pattern for RA treatment in clinics, current status of the hospital and clinic cooperation, and acceptance of the biologic therapy. 　Results: One hundred clinics responded to the questionnaire. Seventy percent of the clinics reported making referrals to rheumatologists before the initiation of RA treatment, and half of the other 30% of the clinics administered methotrexate as the first-line treatment for RA by their own decision. Sixty-six clinics cooperated with flagship hospitals, conducting medical and laboratory examinations, providing prescriptions, and treating common diseases of patients. These clinics expected the cooperating rheumatologists to follow-up patients every 3 to 6 months and to make the diagnosis, make decisions regarding RA treatment changes, and perform surgery. Seventy-one percent of the clinics responded that cooperation with a hospital is possible even for patients who are administered biologics. As reasons for no cooperation with the flagship hospitals, clinics noted the lack of information about rheumatologists in the area and recent trends in the management of RA. 　Conclusion: The current study reported, for the first time, the actual conditions of management of RA in clinics, as well as future problems of hospital and clinic cooperation in Okayama Prefecture