Robot-assisted low anterior resection in a patient with rectal cancer who had a urinary reservoir: A case report

Undergoing another surgery after a previous abdominal procedure can sometimes result in significant abdominal adhesions. We present a case of robot-assisted low anterior resection in a patient with rectal cancer who had a urinary reservoir. A 65-year-old male patient underwent robot-assisted total bladder resection and creation of a urinary reservoir for bladder cancer in 2013. He presented with melena. Thus, the findings revealed advanced low rectal cancer. The robot-assisted low anterior resection was performed in 2022. Extensive adhesions were observed in the pelvic space. The indocyanine green function was appropriately used, and the robotic surgery was completed without injury to the urinary reservoir or major complications. The surgical time was 510 min, and the blood loss volume was 15 mL. The patient had been recurrence free for 12 months following the surgery. Robot-assisted surgery can be beneficial for patients with rectal cancer with significant pelvic adhesions.

Phase II Clinical Trial of Hypofractionated Image-Guided Proton Therapy with 12 Fractions for Prostate Cancer

PURPOSE/OBJECTIVE(S)

Towards hypofractionated proton therapy for prostate cancer for improving convenience for patients to receive treatment and improving therapeutic efficacy, image-guided technique with hydrogel spacer solved the late gastrointestinal toxicity, but it is unclear whether acute genitourinary (GU) toxicity is acceptable. The aim of this phase II study was to evaluate the safety and efficacy of hypofractionated image-guided proton therapy (IGPT) with 12 fractions for prostate cancer.

MATERIALS/METHODS

Eligibility criteria were as follows: (1) histologically confirmed primary prostate cancer; (2) T1-T3bN0M0 staged by (UICC TNM8th); (3) ECOG-PS ≤ 2; (4) age ≥ 20 years; (5) no serious underlying disease or other cancers; (6) technically capable of proton therapy, and (7) written informed consent. Primary endpoint was the ratio of grade 2 or more acute genitourinary toxicity. We used the modified CTCAE grading of grade 2 GU toxicities, in which prescribing two and more types of drugs for dysuria within 3 months of the start of radiation was considered to indicate grade 2 GU toxicity. A phase II trial was planned based on the minimax Simon's two-stage design with a significance level of 0.05 and a power of 90%. The acceptable incidence is considered to be less than 5%, and the unacceptable incidence is considered to be more than 15%. A total of 83 patients is required for completion of the trial (7 patients or fewer). After evaluating the primary endpoint in 83 patients, 217 additional patients were registered and a total of 300 patients were registered in order to further examine the safety and efficacy. The prescribed dose to the isocenter was 51.6 GyRBE in 12 fractions (4 days a week).

RESULTS

From January 2020 to March 2021, 30, 53, and 217 patients (total 300) were enrolled. The patient characteristics were as follows: median age, 70 (48-83) years; low/intermediate/high risk, 44/132/124. Forty-nine and 38 patients had benign prostatic hyperplasia and diabetes mellitus, respectively. Grade 2 acute GU toxicities were observed in 1, 5 and 13 patients, respectively (total 6.3%). No grade 3 or higher acute GU toxicities were observed. However, urinary retention during IGPT, which was not previously observed, was observed in 3 cases, and temporary urethral catheterization was performed (Grade 2). Most of the acute GU toxicity tended to improve at 1 month after IGPT, and almost improved at 3 months. Mean score deteriorations beyond the minimum clinically important difference threshold (1/2 SD) were observed only at 1 month in the following scales: summary (-6.0), bother (-7.0), and irritative/obstructive (-6.3).

CONCLUSION

Hypofractionated IGPT with 12 fractions for prostate cancer is well tolerated in acute GU toxicities. Longer follow-up is necessary to evaluate the efficacy and late toxicities. Further investigation of hypofractionated IGPT with 12 fractions for prostate cancer is warranted. Since April 2021, an additional 1000 cases of prospective registration study have been conducted.

Immunomodulatory Effect of Proteasome Inhibitors via the Induction of Immunogenic Cell Death in Myeloma Cells

Several anti-cancer drugs are known to have immunomodulatory effects, including immunogenic cell death (ICD) of cancer cells. ICD is a form of apoptosis which is caused by the release of damage-associated molecular patterns (DAMPs), the uptake of cancer antigens by dendritic cells, and the activation of acquired immunity against cancer cells. ICD was originally reported in solid tumors, and there have been few reports on ICD in multiple myeloma (MM). Here, we showed that proteasome inhibitors, including carfilzomib, induce ICD in myeloma cells via an unfolded protein response pathway distinct from that in solid tumors. Additionally, we demonstrated the potential impact of ICD on the survival of patients with myeloma. ICD induced by proteasome inhibitors is expected to improve the prognosis of MM patients not only by its cytotoxic effects, but also by building strong immune memory response against MM cells in combination with other therapies, such as chimeric antigen receptor-T cell therapy.

Ambulatory sagittal split ramus osteotomy: strategy for enhanced recovery after surgery

The sagittal split ramus osteotomy (SSRO) has been performed mainly on an inpatient basis because of the duration of anaesthesia and the potential risk of postoperative complications, such as bleeding, pain, nausea, and vomiting. However, advances in both surgical and anaesthetic management have enabled the reduction of these risks and shortened the length of hospital stay. Thus, the SSRO may be feasible even in the ambulatory setting in elective cases. The clinical records of all patients who underwent an outpatient SSRO between August 2011 and September 2020 at Lilla Craniofacial Clinic were reviewed retrospectively. Data on age, sex, duration of surgery, operative procedures, intraoperative bleeding, and admission status were investigated. In total, 143 patients underwent a bilateral SSRO. The SSRO was performed as an isolated procedure in 73 patients and concomitantly with other surgical procedures in the remaining 70 patients. Overall, 142 of the 143 patients were discharged on the day of surgery (99.3%); only one (0.7%) required an overnight stay because of a submental haemorrhage after genioplasty. No emergency hospitalizations or readmissions occurred after discharge. Multimodal perioperative management, both surgical and anaesthetic, facilitated enhanced patient recovery after surgery, and SSRO was performed successfully and safely as an ambulatory procedure.

GTN057, a komaroviquinone derivative, induced myeloma cells' death in vivo and inhibited c-MET tyrosine kinase

OBJECTIVE

Despite the development of newly developed drugs, most multiple myeloma (MM) patients with high-risk cytogenetic abnormalities such as t(4;14) or del17p relapse at anin early stage of their clinical course. We previously reported that a natural product,komaroviquinone (KQN), isolated from the perennial semi-shrub Dracocephalum komarovi, i.e., komaroviquinone (KQN) and its derivative GTN024 induced the apoptosis of MM cells by producing reactive oxygen species (ROS), but both exhibited significant hematological toxicity. Aim of this study is to clarify anti-tumor activity, safety and pharmacokinetics of GTN057, an optimization compound of KQN in vivo.

METHODS

ICR/SCID xenograft model of KMS11, a t(4;14) translocation-positive MM cell line, was used for in vivo study. Mice pharmacokinetics of GTN057 and the degradation products were analyzed by LC-MS/MS.

RESULTS

Herein, our in vitro experiments revealed that GTN057 is much less toxic to normal hematopoietic cells, induced the apoptosis of both MM cell lines andpatient samples, including those with high-risk cytogenetic changes. A xenograft model of a high-risk MM cell line demonstrated that GTN057 significantly delayed the tumor growth with no apparent hematological or systemic toxicities in vivo. The pathological examination of GTN057-treated tumors in vivoshowed revealed apoptosis of MM cells and anti-angiogenesis. In addition to the production of ROS, GTN057 inhibited the downstream signaling of c-MET, a receptor tyrosine kinase a receptor forand hepatocyte growth factor (HGF) receptor. Thus, GTN057 is less toxic and is able tomay be a candidate drug for treating MM patients, via multifunctional mechanisms. We have also extensively studied the pharmacologyical analysis of GTN057. The metabolites of GTN057, (e.g.,such as GTN054), may also have anti-tumorantitumor activity.

CONCLUSION

Natural products or and their derivatives can could be good sources of antineoplastic drugs even for high-risk cancer.

Negative E-cadherin expression on bone marrow myeloma cell membranes is associated with extramedullary disease

Background: The loss of E-cadherin expression and the induction of N-cadherin are known as hallmarks of the epithelial-to-mesenchymal transition, an essential initial step in the process of metastasis in solid tumors. Although several studies have reported expressions of these cadherins in patients with multiple myeloma (MM), their clinical significance is unknown as MM cells are non-epithelial. Methods: In this study, we examined the expression of E- and N-cadherins by immunohistochemistry using bone marrow (BM) biopsy specimens from 31 newly diagnosed MM patients and in subsequent biopsy specimens from six of these. Results: Negative E-cadherin expression on BM myeloma cell membranes was significantly associated with the presence of soft-tissue masses arising from bone lesions and breaking through the cortical bone, referred to as extramedullary disease (EMD). Conclusions: Given the aggressive nature of EMD, our study suggests that screening for E-cadherin using BM immunohistochemistry is one measure that could predict the development of EMD in patients with MM.

Dietary Supplementation with Sodium Butyrate Reduces High-sucrose Diet-induced Hepatic Accumulation of Triacylglycerols and Expression of Fatty Acid Synthesis Enzymes in Rats

We investigated the effects of dietary supplementation with sodium butyrate (NaB) on the lipid levels, gene expression, and proteins related to lipid metabolism in nonalcoholic fatty liver disease (NAFLD) rat models fed a high-sucrose diet for 3 weeks. Supplementation with 1% and 3% NaB reduced high-sucrose-induced hepatic triacylglycerol levels and expression of genes and proteins related to fatty acid synthesis, such as fatty acid synthase and malic enzyme, in a dose-dependent manner. NaB supplementation did not affect hepatic cholesterol levels or expression of genes related to β-oxidation. NaB may prevent high-sucrose-induced NAFLD by repressing the fatty acid synthesis pathway.

SORT1/LAMP2-mediated extracellular vesicle secretion and cell adhesion are linked to lenalidomide resistance in multiple myeloma

Multiple myeloma (MM) is a hematopoietic malignancy whose prognosis has improved with the development of new agents such as lenalidomide over the last decade. However, long-term exposure to drugs induces the acquisition of resistance by MM cells and leads to treatment failure and poor prognosis. Here, we show the molecular and cellular mechanisms of lenalidomide resistance in MM. In a comparison between lenalidomide-resistant cell lines and the parental cell lines, extracellular vesicle (EV) secretion and adherence abilities were significantly elevated in the resistant cells. Whole-transcriptome analysis revealed that the SORT1 and LAMP2 genes were key regulators of EV secretion. Silencing of these genes caused decreased EV secretion and loss of cell adhesion in the resistant cells, resulting in increased sensitivity to lenalidomide. Analysis of publicly available transcriptome data confirmed the relationship between genes related to EV secretion and cell adhesion and patient prognosis. Together, our findings reveal a novel mechanism of lenalidomide resistance in MM mediated by EV secretion and cell adhesion via SORT1 and LAMP2.

Negative E-cadherin expression on bone marrow myeloma cell membranes is associated with extramedullary disease

Background: The loss of E-cadherin expression and the induction of N-cadherin are known as hallmarks of the epithelial-to-mesenchymal transition, an essential initial step in the process of metastasis in solid tumors. Although several studies have reported expressions of these cadherins in patients with multiple myeloma (MM), their clinical significance is unknown as MM cells are non-epithelial. Methods: In this study, we examined the expression of E- and N-cadherins by immunohistochemistry using bone marrow (BM) biopsy specimens from 31 newly diagnosed MM patients and in subsequent biopsy specimens from six of these. Results: Negative E-cadherin expression on BM myeloma cell membranes was significantly associated with the presence of soft-tissue masses arising from bone lesions and breaking through the cortical bone, referred to as extramedullary disease (EMD). Conclusions: Given the aggressive nature of EMD, our study suggests that screening for E-cadherin using BM immunohistochemistry is one measure that could predict the development of EMD in patients with MM.

[PAX5-positive plasma cell leukemia presenting as lymphocytosis]

An 82-year-old Japanese male patient was initially diagnosed with lymphocytosis. His complete blood count revealed a white blood cell count of 30.9×10⁹/l with 81% abnormal lymphocytes. The abnormal lymphocytes included monoclonal clones of CD38⁺ and CD138⁺cytoplasmic κ⁺ and IgG-κ M-protein, which led to the final diagnosis of plasma cell leukemia (PCL). Bortezomib and dexamethasone therapy was initiated, but the patient succumbed to the disease on the 8th day of hospitalization. A cytogenetic examination revealed a t (9;14)(p13;q32) translocation and the Western blotting confirmed high PAX5 expression. Similar to our present case, PCL cases with "lymphocytosis" have been widely reported, which some speculating the involvement of PAX5 overexpression in the pathogenesis. Such cases, including ours, may be classified as a unique group of disorders (PCL presenting as "lymphocytosis"), which requires accurate differential diagnosis and subsequent urgent multidisciplinary intensive treatment.

[A Case of Synchronous Multiple Colorectal Cancer with Rectal Neuroendocrine Tumor and Ascending Colon Cancer]

A 43-year-old man who had no previous medical history or family history had positive fecal occult blood test in a local physician. Colonoscopy revealed a type 2 tumor of the ascending colon and a 10 mm submucosal tumor(SMT)of the lower rectum. Biopsy indicated moderately-differentiated adenocarcinoma of the ascending colon and neuroendocrine tumor (NET)of the lower rectum. No metastasis was detected by computed tomography. Therefore, the rectal SMT was resected first by endoscopic submucosal resection. Histopathologically, the lesion was localized in the submucosa and no lymphovascular invasion was found. Vertical margin was also negative. We decided not to perform additional intestinal resection for rectal NET. Thereafter, the patient underwent laparoscopic right hemicolectomy for ascending colon cancer. The histopathological findings were pT3, pN1, pM0, pStage Ⅲb. The patient received adjuvant chemotherapy. No relapse was found 18 months after surgery. We reported a rare case of a lower rectal NET with concomitant ascending colon cancer.

[A Case of Advanced Rectal Cancer with Left Hydronephrosis Treated with Left Ureter-Sparing Laparoscopic High Anterior Resection after Chemotherapy]

A 47-year-old woman with a complaint of weight loss for the past 5 months was referred to our hospital. Colonoscopy revealed advanced rectal cancer 20 cm from the anal verge. The patient had left hydronephrosis caused by ureteral invasion. Firstly, we performed transverse colostomy and left nephrostomy. After 8 courses of capecitabine, oxaliplatin plus bevacizumab( CAPOX plus Bmab)therapy, colonoscopy and computed tomography revealed shrinkage of both the primary and metastatic lesions. Laparoscopic high anterior resection was performed, and the left ureter was successfully preserved. The patient received chemotherapy after surgery. Neither local recurrence nor enlargement of metastases has been observed 8 months after surgery.

[A Case of Esophagogastric Junction Cancer Treated Successfully with Conversion Surgery after Complete Response to Nivolumab Treatment]

As shown in the ATTRACTION-2 trial, nivolumab is effective as third-line chemotherapy for advanced or recurrent gastric cancer and esophagogastric junction cancer. We report a patient with esophagogastric junction cancer who underwent conversion surgery after third-line chemotherapy with nivolumab. The patient was a 72-year-old woman. Upper gastrointestinal endoscopy revealed advanced esophagogastric junction cancer of Siewert type Ⅱ, and computed tomography revealed multiple hepatic and pulmonary metastases. The esophagogastric junction cancer was diagnosed as cT3N1M1, cStage Ⅳb, and she was administered SP as first-line and nab-PTX/RAM as second-line treatment, but progressive disease remained. Nivolumab as a third-line treatment remarkably reduced the hepatic and pulmonary metastases after its administration was initiated, and conversion surgery was performed after 28 courses. The pathological diagnosis was ypT1b2(SM2), ypN0. After discharge from the hospital, postoperative chemotherapy with nivolumab was continued in the outpatient clinic, and there has been no evidence of disease progression.

Thermally-modulated cell separation columns using a thermoresponsive block copolymer brush as a packing material for the purification of mesenchymal stem cells

Cell therapy using mesenchymal stem cells (MSCs) is used as effective regenerative treatment. Cell therapy requires effective cell separation without cell modification and cellular activity reduction. In this study, we developed a temperature-modulated mesenchymal stem cell separation column. A temperature-responsive cationic block copolymer, poly(N,N-dimethylaminopropylacrylamide)-b-poly(N-isopropylacrylamide)(PDMAPAAm-b-PNIPAAm) brush with various cationic copolymer compositions, was grafted onto silica beads via two-step atom transfer radical polymerization. Using the packed beads, the elution behavior of the MSCs was observed. At 37 °C, the MSCs were adsorbed onto the column via both hydrophobic and electrostatic interactions with the PNIPAAm and PDMAPAAm segments of the copolymer brush, respectively. By reducing the temperature to 4 °C, the adsorbed MSCs were eluted from the column by reducing the hydrophobic and electrostatic interactions attributed to the hydration and extension of the PNIPAAm segment of the block copolymer brush. From the temperature-modulated adsorption and elution behavior of MSCs, a suitable DMAPAAm composition of the block copolymer brush was determined. Using the column, a mixture of MSC and BM-CD34⁺ cells was separated by simply changing the column temperature. The column was used to purify the MSCs, with purities of 78.2%, via a temperature change from 37 °C to 4 °C. Additionally, the cellular activity of the MSCs was retained throughout the column separation step. Overall, the obtained results show that the developed column is useful for MSC separation without cell modification and cellular activity reduction.

Antibody drug separation using thermoresponsive anionic polymer brush modified beads with optimised electrostatic and hydrophobic interactions

Antibody drugs play an important role in biopharmaceuticals, because of the specificity for target biomolecules and reduction of side effects. Thus, separation and analysis techniques for these antibody drugs have increased in importance. In the present study, we develop functional chromatography matrices for antibody drug separation and analysis. Three types of polymers, poly(N-isopropylacrylamide (NIPAAm)-co-2-acrylamido-2-methylpropanesulfonic acid (AMPS)-co-N-phenyl acrylamide (PhAAm)), P(NIPAAm-co-AMPS-co-n-butyl methacrylate (BMA)), and P(NIPAAm-co-AMPS-co-tert-butylacrylamide (tBAAm)), were modified on silica beads through atom transfer radical polymerisation. Rituximab elution profiles were observed using the prepared beads-packed column. Rituximab adsorption at high temperature and elution at low temperature from the column were observed, as a result of the temperature-modulated electrostatic and hydrophobic interactions. Using the column, rituximab purification from contaminants was performed simply by changing the temperature. Additionally, three types of antibody drugs were separated using the column through temperature-modulated hydrophobic and electrostatic interactions. These results demonstrate that the temperature-responsive column can be applied for the separation and analysis of biopharmaceuticals through a simple control of the column temperature.

Abstract B73: A novel candidate for immunologic target in treatment of multiple myeloma

Background: Despite the development of novel drugs, including immune modulatory drugs (IMiDs) and proteasome inhibitors, multiple myeloma is still an uncurable disease. In particular, patients with high-risk chromosomal abnormalities, such as t (4;14) or del17, have poor prognosis. Recently, antibodies or CAR-T cells have been shown to be effective, suggesting that myeloma cells are sensitive to immune reactions. We have previously identified an HLA-A*24:02-restiricted epitope from a novel cancer-testis antigen CXorf48. In this study, we aim to characterize cytotoxic T lymphocyte (CTL) against this antigen and investigate the possibility of the CTLs for adoptive T-cell therapy in myeloma treatments.

Methods: Expression of CXorf48 gene was examined by RT-PCR of myeloma cell lines. We then treated myeloma cells with low CXorf48 expressions by demethylating agents, 5-azacytidine (5-aza) or 5-aza-2’-deoxycytidine (DAC), and checked the expression level of this gene by quantitative RT-PCR. Furthermore, CXorf48-specific CTLs were induced from peripheral blood mononuclear cells of HLA-A*24:02-positive healthy donors and their antigen recognition was examined by ELISpot assay and 51Cr cytotoxicity assay. We also analyzed T-cell receptor (TCR) repertoire using dextramer-sorted CTLs and transduced the TCR genes into Jurkat cells.

Results: Expression of CXorf48 gene was found in most myeloma cell lines including those with t (4;14) or del17. In addition, the gene expression was significantly increased by DAC in CXorf48-low myeloma cells, which caused enhanced recognition by anti-CXorf48 CTLs. We also identified CXorf48-specidfic TCR genes of CTLs from two donors, and generated TCR gene-transduced T cells.

Conclusions: CXorf48 might be a useful target for immunotherapy in combination with demethylating agents for high-risk myeloma. Aiming at CXorf48-specific adoptive therapy, we are analyzing CXorf48-specific TCR-transduced human T cells.

Citation Format: Maiko Matsushita, Saku Saito, Kanae Mori, Shinya Yokoe, Daiju Ichikawa, Yutaka Hattori. A novel candidate for immunologic target in treatment of multiple myeloma [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2019 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(3 Suppl):Abstract nr B73.

Significance of peripheral mononuclear cells producing interferon-γ in response to insulin B:9-23-related peptides in subtypes of type 1 diabetes

Type 1 diabetes is largely caused by β-cell destruction through anti-islet autoimmunity. Reportedly, interferon (IFN)-γ-secreting peripheral blood mononuclear cells (PBMCs) specific to four insulin B-chain amino acid 9-23-related peptides (B:9-23rPep) were increased in type 1 diabetes participants. This study aimed to investigate the PBMC frequencies in subtypes of type 1 diabetes using enzyme-linked immunospot assay. In this cross-sectional study, peripheral blood samples were obtained from 148 participants including 72 with acute-onset type 1 diabetes (AT1D), 51 with slowly progressive insulin-dependent diabetes mellitus (SPIDDM), and 25 with type 2 diabetes. The frequency of B:9-23rPep-specific IFN-γ-producing PBMCs was significantly higher in AT1D participants than in SPIDDM and type 2 diabetes participants. Meanwhile, a significant inverse correlation was observed between the PMBC frequencies and insulin secretion capacity in SPIDDM participants. These findings suggest that the increased peripheral B:9-23rPep-specific IFN-γ immunoreactivity reflects decreased functional β-cell mass and greater disease activity of type 1 diabetes.

Temperature-modulated cell-separation column using temperature-responsive cationic copolymer hydrogel-modified silica beads

There is strong demand for cell separation methods that do not decrease cell activity or modify cell surfaces. Here, new temperature-modulated cell-separation columns not requiring cell-surface premodification are described. The columns were packed with temperature-responsive cationic polymer hydrogel-modified silica beads. Poly(N-isopropylacrylamide-co-n-butyl methacrylate-co-N,N-dimethylaminopropyl acrylamide) hydrogels with various cationic moieties were attached to silica-bead surfaces by radical polymerization using N,N'-methylenebisacrylamide as a crosslinking agent. The beads were packed into solid-phase extraction columns, and temperature-dependent cell elution from the columns was found using HL-60 and Jurkat cells. The retention HL-60 and Jurkat cells in columns containing cationic beads at 37 °C was 95.3% to 99.6% and 95.0% to 98.8%, respectively. By contrast, beads without cationic properties exhibited low cell retention (20.6% for HL-60 and 32.5% for Jurkat cells). The cells were mainly retained through both electrostatic and hydrophobic interactions. The retained HL-60 (4.9%) and Jurkat cells (40%) were eluted at 4 °C from the column with a low composition of cationic monomer (DMAPAAm, 1 mol% in copolymer), because the temperature-responsive hydrogels on the beads became hydrophilic, decreasing the hydrophobic interactions between the cells and the beads. A higher number of Jurkat cells than HL-60 cells were eluted because of differences in their electrostatic properties (Jurkat cells: -2.53 mV; HL-60 cells: -20.7 mV). The results indicated that cell retention by the hydrogel-coated beads packed in a solid phase extraction column could be modulated simply by changing the temperature.

Abstract B177: Analysis of immunogenic cell death (ICD) induced in multiple myeloma cells

Background: Development of novel drugs, such as immunomodulatory drugs (IMiDs), proteasome inhibitors (PIs), or monoclonal antibodies, has prolonged survival of multiple myeloma (MM) patients. However, high-risk patients harboring del 17, t(14;17), or t(11;14) still have poor prognosis. Therefore, clarification of the drugs that could potentiate the effect of these treatments is necessary. Several drugs have been reported to cause cell surface expression of calreticulin (CRT), release of high mobility group box 1 (HMGB 1) and ATP, activating an immune response, which is called immunogenic cell death (ICD). However, there is almost no information on ICD in MM. The purpose of this study is to investigate whether anti-MM drugs can induce not only direct cell-killing effect but also immunomodulatory effects in high-risk MM cells. Methods: High-risk myeloma cell line, MUM24 was treated with dexamethasone, melphalan, lenalidomide, bortezomib, carfilzomib, and panobinostat. Expression of cell surface CRT and HMGB1 release were detected using flow cytometry and Western blotting, respectively. We then co-cultured DiD-labeled monocyte-derived dendritic cells with GFP-induced MUM24 treated with each drug and evaluated phagocytosis of DCs using fluorescence microscope. Results: After treatment with drugs, bortezomib and carfilzomib induced higher expression of CRT and release of HMGB1 in MUM24 compared with other drugs. We also observed that DCs could engulf MUM24 cells treated with carfilzomib. Conclusion: Our results suggest that PIs, such as bortezomib or carfilzomib, could not only kill MM cells but also induce ICD. These effects are expected to improve the prognosis of MM patients by evoking strong immune response against MM cells.

Citation Format: Maiko Matsushita, Sho Kashiwazaki, Satoshi Kamiko, Ryo Uozaki, Daiju Ichikawa, Yutaka Hattori. Analysis of immunogenic cell death (ICD) induced in multiple myeloma cells [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr B177.

[A Case of Robot-Assisted Conversion Surgery for Gastric Cancer with Peritoneal Dissemination That Responded to Intravenous and Intraperitoneal Paclitaxel Combined with S-1 Chemotherapy]

This case involved a 69-year-old female patient with peritoneal dissemination of an advanced gastric cancer. She underwent chemotherapy comprisingintravenous and intraperitoneal paclitaxel combined with S-1. After 20 courses, a staging laparoscopy was performed, and pathological analysis of the peritoneal dissemination and cytologic analysis of ascites fluid yielded negative results. A radical robot-assisted total gastrectomy was successfully performed. The pathological stage was determined to be ypT4aN2M0, ypStage ⅢB. We continued to administer the same chemotherapy regimen for 15 courses (total: 35 courses)after surgery. No recurrence has been detected during the 1-year period after surgery.

Abstract A82: Evaluation of novel immune target in hematologic malignancies

Background and Objective: Development of drugs such as tyrosine kinase inhibitors (TKIs), immunomodulatory drugs (IMiDs), or proteasome inhibitors (PIs) have improved survival of hematologic malignancies including chronic myeloid leukemia (CML) and multiple myeloma (MM). However, some patients eventually relapse by discontinuation of the drugs or acquiring resistance to the drugs. Thus, it is crucial to develop novel therapy for cure of these malignancies. CML and MM are considered to be relatively immunogenic diseases among hematologic malignancies and immunotherapy might be useful. Since CML cells or MM cells have few somatic mutations which result in amino acid changes and give rise to neoantigens, checkpoint inhibitors alone may not be sufficient to evoke effective immunity against these cells. Instead, overexpressed antigen may be an attractive therapeutic target. We have identified CXorf48 as a highly expressed antigen in several hematologic malignancies including CML and MM. In this study, we investigated whether CXorf48 could serve as a therapeutic target for CML and MM.

Methods and Results: High expression of CXorf48 gene in CML cells and MM cells was confirmed by quantitative PCR and also patients’ gene data obtained from a public repository. In contrast, BMMNCs cells or PBMNCs from healthy donor did not express CXorf48. We induced CXorf48-specific cytotoxic T lymphocytes (CTLs) by stimulating lymphocytes from healthy donors with HLA-A24:02-restricted CXorf48-derived epitope peptide. ELISpot assay, cytotoxic assay and CD107a mobilization assay showed that these CTLs preferentially recognized CML cells and MM cells. Moreover, we could detect CXorf48-specific CTL in peripheral blood of CML patients who remained in complete molecular remission after cessation of TKIs.

Conclusion: Our data suggest that CXorf48 is a novel therapeutic target of CTLs in CML or MM. Immunotherapy against this antigen, such as vaccination therapy or adoptive T-cell therapy after conventional therapies might be an attractive therapeutic strategy for cure of CML and MM.

Citation Format: Maiko Matsushita, Shinya Yokoe, Koji Ozawa, Saori Kanchi, Daiju Ichikawa, Eri Matsuki, Takehiko Mori, Shinichiro Okamoto, Yutaka Hattori. Evaluation of novel immune target in hematologic malignancies [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2017 Oct 1-4; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2018;6(9 Suppl):Abstract nr A82.

Analysis of masticatory muscle coordination during unilateral single-tooth clenching using muscle functional magnetic resonance imaging

In a previous study, we used muscle functional magnetic resonance imaging to show that the anterior movement of the occlusal point increased the activity of the superior head of the ipsilateral lateral pterygoid muscle (ipsilateral SHLP) during unilateral single-tooth clenching. The purpose of this study was to verify the hypothesis that the increased activity of the ipsilateral SHLP described above serves to antagonise the occlusal force acting on the condyle. In total, 9 healthy volunteers were requested to perform left unilateral clenching at the first molar or first premolar region for 1 minute at 20% or 40% maximum voluntary clenching force. Changes in the mean proton transverse relaxation time (∆T2) were examined from the magnetic resonance images obtained before and after each clenching act as an index of the activity in all masticatory muscles. Correlation analyses of the mean ΔT2 for each volume of interest were performed with the first molar or premolar clenches to analyse the correlation between the activities in each muscle. A statistically significant correlation was exhibited between the ipsilateral temporal and ipsilateral SHLP (r = .651, P = .003) during first premolar clenching. However, no significant correlations were observed in the ipsilateral SHLP during first molar clenching. The results of this study suggest that the ipsilateral SHLP may contribute to the pulling of the mandibular condyle forward against the occlusal force generated by the ipsilateral temporal muscle.

Fibroblast growth factor 13 regulates glioma cell invasion and is important for bevacizumab-induced glioma invasion

Glioblastoma has the poorest prognosis, and is characterized by excessive invasion and angiogenesis. To determine the invasive mechanisms, we previously used two glioma cell lines (J3T-1 and J3T-2) with different invasive phenotypes. The J3T-1 showed abundant angiogenesis and tumor cell invasion around neovasculature, while J3T-2 showed diffuse cell infiltration into surrounding healthy parenchyma. Microarray analyses were used to identify invasion-related genes in J3T-2 cells, and the expressed genes and their intracellular and intratumoral distribution patterns were evaluated in J3T-2 cell lines, human glioma cell lines, human glioblastoma stem cells and human glioblastoma specimens. To determine the role of the invasion-related genes, invasive activities were evaluated in vitro and in vivo. Fibroblast growth factor 13 (FGF13) was overexpressed in J3T-2 cells compared to J3T-1 cells, and in human glioma cell lines, human glioblastoma stem cells and human glioblastoma specimens, when compared to that of normal human astrocytes. Immunohistochemical staining and the RNA-seq (sequencing) data from the IVY Glioblastoma Atlas Project showed FGF13 expression in glioma cells in the invasive edges of tumor specimens. Also, the intracellular distribution was mainly in the cytoplasm of tumor cells and colocalized with tubulin. Overexpression of FGF13 stabilized tubulin dynamics in vitro and knockdown of FGF13 decreased glioma invasion both in vitro and in vivo and prolonged overall survival of several xenograft models. FGF13 was negatively regulated by hypoxic condition. Silencing of FGF13 also decreased in vivo bevacizumab-induced glioma invasion. In conclusion, FGF13 regulated glioma cell invasion and bevacizumab-induced glioma invasion, and could be a novel target for glioma treatment.

CXorf48 is a potential therapeutic target for achieving treatment-free remission in CML patients

Although the introduction of tyrosine kinase inhibitors (TKIs) has improved overall survival of patients with chronic myeloid leukemia (CML), about half of the patients eventually relapse after cessation of TKIs. In contrast, the remainder of the patients maintain molecular remission without TKIs, indicating that the patients' immune system could control proliferation of TKI-resistant leukemic stem cells (LSCs). However, the precise mechanism of immunity against CML-LSCs is not fully understood. We have identified a novel immune target, CXorf48, expressed in LSCs of CML patients. Cytotoxic T cells (CTLs) induced by the epitope peptide derived from CXorf48 recognized CD34⁺CD38^- cells obtained from the bone marrow of CML patients. We detected CXorf48-specific CTLs in the peripheral blood mononuclear cells from CML patients who have discontinued imatinib after maintaining complete molecular remission for more than 2 years. Significantly, the relapse rate of CXorf48-specific CTL-negative patients was 63.6%, compared to 0% in CXorf48-specific CTL-positive patients. These results indicate that CXorf48 could be a promising therapeutic target of LSCs for immunotherapy to obtain durable treatment-free remission in CML patients.

Synthesis and biological evaluation of the natural product komaroviquinone and related compounds aiming at a potential therapeutic lead compound for high-risk multiple myeloma

Alternatives of treatments for multiple myeloma (MM) have become increasingly available with the advent of new drugs such as proteasome inhibitors, thalidomide derivatives, histone deacetylase inhibitors, and antibody drugs. However, high-risk MM cases that are refractory to novel drugs remain, and further optimization of chemotherapeutics is urgently needed. We had achieved asymmetric total synthesis of komaroviquinone, which is a natural product from the plant Dracocephalum komarovi. Similar to several leading antitumor agents that have been developed from natural compounds, we describe the antitumor activity and cytotoxicity of komaroviquinone and related compounds in bone marrow cells. Our data suggested that komaroviquinone-related agents have potential as starting compounds for anticancer drug development.

Abstract 5121: PEG(E)-TC11, a novel polyethylene glycol-linked phthalimide derivative, inhibited high-risk MM cell growth in vivo and in vitro via cell cycle G2/M arrest in a CRBN-independent manner

Multiple myeloma (MM) is one of the hematological malignancy that is characterized by proliferation of malignant plasma cells. Recent advance in the treatment of MM using newly developed drugs, prognosis of the MM patients have been significantly improved. For example, immunomodulatory drugs (IMiDs) such as thalidomide, lenalidomide and pomalidomide have been developed for treatment of MM. However, IMiDs have only limited effects against MM patients with high risk chromosomal abnormalities such as t(4;14) and del17p (high-risk MM). In 2010, it was reported that IMiDs directly bind to cereblon (CRBN), a component of ubiquitin ligase 3 complex, and induced teratogenicity as well as anti-tumor effects. We have previously reported that a novel phthalimide derivative, 2-(2,6-diisopropylphenyl)-5-amino-1H-isoindole-1,3-dione (TC11) induced apoptosis against high-risk MM cells in vivo and in vitro, and inhibited differentiation of osteoclasts. We also reported that TC11 directly bound to α-tubulin and nucleophosmin-1 (NPM1), but did not bind to CRBN. However, TC11 was not well dissolved in water with only 0.02 mg/mL solubility. Therefore, TC11 showed poor absorption into blood and limited anti-tumor activity when it was intraperitoneally administered in tumor-bearing mice.

To resolve these problems, we synthesized PEG(E)-TC11, in which TC11 is linked to polyethylene glycol through an ester bond, and consequently enhanced water solubility of PEG(E)-TC11 to 88.9 mg/mL. PEG(E)-TC11 revealed as potent growth inhibitory effect on high-risk MM cells as TC11 in vitro. In pharmacokinetic study, PEG-modification of TC11 improved the peak blood concentration (Cmax) from 2.6 to 24.4 μM and extended elimination half-life (t1/2) from 1.4 to 2.2 hr when 186 μM/kg of these compounds were intraperitoneally injected. More importantly, these pharmacokinetic improvement led to more potent growth inhibition of MM cells in vivo than TC11. We also explored mechanisms of anti-myeloma effect of PEG(E)-TC11 and found that PEG(E)-TC11 induced apoptosis via G2/M cell cycle arrest. However, unlike IMiDs family, BIACORE assay revealed that PEG(E)-TC11 didn’t directly bind to CRBN, indicating that growth inhibitory effect of PEG(E)-TC11 against MM cells was independent of binding to CRBN.

In conclusion, PEGylation of TC11 significantly increased water solubility, resulted in potentiated anti-myeloma activity in vivo. Furthermore, PEG(E)-TC11 inhibited cell growth via G2/M arrest in a CRBN-independent manner. Thus, PEG(E)-TC11 is considered as a candidate compound for overcoming high-risk MM.

Citation Format: Shuji Aida, Daiju Ichikawa, Kazuki Iida, Masashi Hozumi, Misa Nakamura, Ryo Uozaki, Nahoko Hashimoto, Mikio Okayama, Yuko Yonemura, Noriko Tabata, Taketo Yamada, Maiko Matsushita, Takeshi Sugai, Hiroshi Yanagawa, Yutaka Hattori. PEG(E)-TC11, a novel polyethylene glycol-linked phthalimide derivative, inhibited high-risk MM cell growth in vivo and in vitro via cell cycle G2/M arrest in a CRBN-independent manner [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5121. doi:10.1158/1538-7445.AM2017-5121

Real-time monitoring of granule properties during high shear wet granulation by near-infrared spectroscopy with a chemometrics approach

An in-line near-infrared spectroscopy monitoring method was developed for analyzing granule properties during a high shear wet granulation process.