Tsutomu Iwasa

Our objectives were to determine whether clinic-pathological markers and immune-related gene signatures in breast cancer exhibit any change upon brain metastasis and whether previously reported genes significantly associated with brain metastases and the epithelial-mesenchymal transition (EMT) were reproducible and consistent in our dataset. Sixteen pair-matched samples from primary breast cancers and brain metastases diagnosed were collected from the Japan Clinical Oncology Group Breast Cancer Study Group. Gene expression profiles for immune-, brain metastases-, and EMT-related genes were compared between primary breast cancers and brain metastases. Potential therapeutic target genes of 41 FDA-approved or under-investigation agents for brain metastases were explored. Immune-related signatures exhibited significantly lower gene expression in brain metastases than in primary breast cancers. No significant differences were detected for the majority of genes associated with brain metastases and EMT in the two groups. Among 41 therapeutic target candidates, VEGFA and DNMT3A demonstrated significantly higher gene expression in brain metastases. We found that distinct patterns of gene expression exist between primary breast cancers and brain metastases. Further studies are needed to explore whether these distinct expression profiles derive from or underlie disease status and compare these features between metastases to the brain and other sites.

PURPOSE: Survivin, a member of the inhibitor of apoptosis protein family, is an attractive target for cancer therapy. We have now investigated the effect of YM155, a small-molecule inhibitor of survivin expression, on the sensitivity of human non-small cell lung cancer (NSCLC) cell lines to gamma-radiation. EXPERIMENTAL DESIGN: The radiosensitizing effect of YM155 was evaluated on the basis of cell death, clonogenic survival, and progression of tumor xenografts. Radiation-induced DNA damage was evaluated on the basis of histone H2AX phosphorylation and foci formation. RESULTS: YM155 induced down-regulation of survivin expression in NSCLC cells in a concentration- and time-dependent manner. A clonogenic survival assay revealed that YM155 increased the sensitivity of NSCLC cells to gamma-radiation in vitro. The combination of YM155 and gamma-radiation induced synergistic increases both in the number of apoptotic cells and in the activity of caspase-3. Immunofluorescence analysis of histone gamma-H2AX also showed that YM155 delayed the repair of radiation-induced double-strand breaks in nuclear DNA. Finally, combination therapy with YM155 and gamma-radiation delayed the growth of NSCLC tumor xenografts in nude mice to a greater extent than did either treatment modality alone. CONCLUSIONS: These results suggest that YM155 sensitizes NSCLC cells to radiation both in vitro and in vivo, and that this effect of YM155 is likely attributable, at least in part, to the inhibition of DNA repair and enhancement of apoptosis that result from the down-regulation of survivin expression. Combined treatment with YM155 and radiation warrants investigation in clinical trials as a potential anticancer strategy.

The expression and activity of the epidermal growth factor receptor (EGFR) are determinants of radiosensitivity in several tumour types, including non-small cell lung cancer (NSCLC). However, little is known of whether genetic alterations of EGFR in NSCLC cells affect the therapeutic response to monoclonal antibodies (mAbs) to EGFR in combination with radiation. We examined the effects of nimotuzumab, a humanised mAb to EGFR, in combination with ionising radiation on human NSCLC cell lines of differing EGFR status. Flow cytometry revealed that H292 and Ma-1 cells expressed high and moderate levels of EGFR on the cell surface, respectively, whereas H460, H1299, and H1975 cells showed a low level of surface EGFR expression. Immunoblot analysis revealed that EGFR phosphorylation was inhibited by nimotuzumab in H292 and Ma-1 cells but not in H460, H1299, or H1975 cells. Nimotuzumab augmented the cytotoxic effect of radiation in H292 and Ma-1 cells in a clonogenic assay in vitro, with a dose enhancement factor of 1.5 and 1.3, respectively. It also enhanced the antitumor effect of radiation on H292 and Ma-1 cell xenografts in nude mice, with an enhancement factor of 1.3 and 4.0, respectively. Nimotuzumab did not affect the radioresponse of H460 cells in vitro or in vivo. Nimotuzumab enhanced the antitumor efficacy of radiation in certain human NSCLC cell lines in vitro and in vivo. This effect may be related to the level of EGFR expression on the cell surface rather than to EGFR mutation.

// Rin Ogiya 1 , Naoki Niikura 1 , Nobue Kumaki 2 , Hiroyuki Yasojima 3 , Tsutomu Iwasa 4 , Chizuko Kanbayashi 5 , Risa Oshitanai 1 , Michiko Tsuneizumi 6 , Ken-ichi Watanabe 7 , Akira Matsui 8 , Tomomi Fujisawa 9 , Shigehira Saji 10 , Norikazu Masuda 3 , Yutaka Tokuda 1 and Hiroji Iwata 11 1 Department of Breast and Endocrine Surgery, Tokai University School of Medicine, Kanagawa, Japan 2 Department of Pathology, Tokai University School of Medicine, Kanagawa, Japan 3 Department of Surgery, Breast Oncology, National Hospital Organization Osaka National Hospital, Osaka, Japan 4 Department of Medical Oncology, Kindai University School of Medicine, Osaka, Japan 5 Department of Breast Oncology, Niigata Cancer Center Hospital, Niigata, Japan 6 Department of Breast Surgery, Shizuoka General Hospital, Shizuoka, Japan 7 Department of Breast Surgery, Hokkaido Cancer Center, Sapporo, Japan 8 Department of Surgery, National Hospital Organization, Tokyo Medical Center, Tokyo, Japan 9 Department of Breast Oncology, Gunma Prefectural Cancer Center, Gunma, Japan 10 Department of Medical Oncology, Fukushima Medical University, Fukushima, Japan 11 Department of Breast Oncology, Aichi Cancer Center Hospital, Nagoya, Japan Correspondence to: Naoki Niikura, email: niikura@is.icc.u-tokai.ac.jp Keywords: breast cancer, brain metastases, tumor infiltrating lymphocytes, PD-L1, immune microenvironment Received: July 11, 2017      Accepted: September 20, 2017      Published: October 27, 2017 ABSTRACT Background: Immune checkpoint inhibitors are reported to be effective in patients with brain metastases. However, detailed characteristics of the brain metastasis immune microenvironment remain unexplored. Results: The median tumor-infiltrating lymphocyte (TIL) category in brain metastases was 5% (1–70%). In 46 pair-matched samples, the percentages of TILs were significantly higher in primary breast tumors than in brain metastases (paired t -test, P < 0.01). The numbers of CD4/CD8/Foxp3-positive cells were significantly higher in primary breast tumors than in brain metastases (paired t -test, P < 0.05 for all antibodies). In patients with triple-negative breast cancer specifically, low TIL numbers were associated with significantly shorter overall survival compared to high TIL numbers (log-rank test, P = 0.04). Materials and Methods: We retrospectively identified 107 patients with breast cancer and brain metastases who had undergone surgery between 2001 and 2012 at 8 institutions, and collected 191 samples including brain metastases alone and primary tumors with pair-matched brain metastasis samples. Hematoxylin and eosin-stained slides were evaluated for TILs and categorized according to the extent of staining. Immunohistochemistry for CD4, CD8, Foxp3, PD-L1, PD-L2, and HLA class I was also performed. Conclusions: There are significantly fewer TILs in brain metastases than in primary breast tumors.