Transvaginal resection of a gastrointestinal stromal tumor of the rectum: a case report.

BACKGROUND: The most common curative treatment for gastrointestinal stromal tumors (GISTs) is local excision. For rectal GISTs, however, local excision is difficult because of the anatomical features of the rectum. The optimal surgical approach is still under debate, and less invasive methods are desired. We herein report a case of transvaginal resection of a rectal GIST in a young woman. CASE PRESENTATION: A 21-year-old woman was diagnosed with a resectable GIST in the anterior rectal wall and underwent transvaginal tumor resection. The posterior vaginal wall was incised, revealing the tumor fully covered by the rectal mucosa. The rectal adventitia and muscular layer were incised, and the tumor was resected en bloc without rupture. The postoperative course was favorable, and the patient was discharged on postoperative day 12. No findings consistent with recurrence were present 6 months postoperatively. CONCLUSION: Transvaginal tumor resection is a treatment option as a minimally invasive procedure for GISTs in the anterior rectal wall in female patients.

PTPN3 Could Βe a Therapeutic Target of Pancreatic Cancer.

BACKGROUND/AIM: Recently, protein tyrosine phosphatase non-receptor type 3 (PTPN3) has gained attention. However, the role of PTPN3 in cancer has not been fully elucidated. In the present study, we analyzed the role of PTPN3 in pancreatic cancer and investigated whether PTPN3 could be a new therapeutic target for pancreatic cancer. MATERIALS AND METHODS: Two pancreatic ductal adenocarcinoma (PDAC) cell lines were used as target cells. Cell proliferation was investigated using cell counting and a xenograft mouse model. Migration and invasion were analyzed using Transwell inserts. Activation-related signaling molecules were examined by western blotting. RESULTS: PTPN3 contributes to the proliferation, migration, and invasion of PDAC cells in vitro. PTPN3 promotes tumor growth in a mouse xenograft model, an action mediated partially through the MAPK pathway. CONCLUSION: PTPN3 could be a new therapeutic target for pancreatic cancer.

Cancer therapy that targets the Hedgehog signaling pathway considering the cancer microenvironment (Review).

Recently, the cancer microenvironment (CME) has received significant attention. At the local site of the tumor, cancer progression is affected by secreted cytokines and conditions derived from the CME and stimulation by cancer­induced cytokines in an autocrine manner. The CME is characterized by various types of conditions, such as hypoxia, inflammation stimulation, and angiogenesis, and contains various components, such as reactive oxygen species, cancer­associated fibroblasts, infiltrated immune cells, exosomes, and cancer stem cells (CSCs). These conditions and components complicate the progression of cancer. The Hedgehog (HH) signaling pathway is a morphogenesis signaling pathway that is reactivated in some cancers. In these cancers, reactivated HH signaling is involved in the induction of the malignant phenotype. HH signaling is also activated under hypoxic conditions and is considered to be strongly correlated with the CME, including the induction of cancer fibrosis and maintenance of CSCs. The aim of the present review was to elucidate a cancer therapy that targets HH signaling by considering the CME, particularly focusing on hypoxia.

TrkB/BDNF Signaling Could Be a New Therapeutic Target for Pancreatic Cancer.

BACKGROUND/AIM: Tropomyosin-related kinase B (TrkB)/brain-derived neurotrophic factor (BDNF) signaling plays a role in inducing malignant phenotypes in several aggressive types of cancers. To create a conclusive therapy targeting TrkB/BDNF signaling in solid refractory cancers, the biological significance of TrkB/BDNF signaling was analyzed in pancreatic ductal adenocarcinoma (PDAC) cells. MATERIALS AND METHODS: Three PDAC cell lines were used as target cells to investigate proliferation and invasiveness. Small interfering RNA (siRNA) and the TrkB tyrosine kinase inhibitor k252a were used as TrkB/BDNF signaling inhibitors. RESULTS: All PDAC cell lines expressed TrkB and BDNF. When TrkB and BDNF were inhibited by siRNA or k252a, the invasiveness of PANC-1 and SUIT-2 cells significantly decreased. When TrkB was inhibited by siRNA or k252a, proliferation was significantly inhibited in PDAC cells. CONCLUSION: TrkB/BDNF signaling may be a new therapeutic target for PDAC. Therapies targeting TrkB/BDNF signaling may be a conclusive cancer therapy for refractory solid cancer.

GLI2 but not GLI1/GLI3 plays a central role in the induction of malignant phenotype of gallbladder cancer.

We previously reported that Hedgehog (Hh) signal was enhanced in gallbladder cancer (GBC) and was involved in the induction of malignant phenotype of GBC. In recent years, therapeutics that target Hh signaling have focused on molecules downstream of smoothened (SMO). The three transcription factors in the Hh signal pathway, glioma­associated oncogene homolog 1 (GLI1), GLI2, and GLI3, function downstream of SMO, but their biological role in GBC remains unclear. In the present study, the biological significance of GLI1, GLI2, and GLI3 were analyzed with the aim of developing novel treatments for GBC. It was revealed that GLI2, but not GLI1 or GLI3, was involved in the cell cycle­mediated proliferative capacity in GBC and that GLI2, but not GLI1 or GLI3, was involved in the enhanced invasive capacity through epithelial­mesenchymal transition. Further analyses revealed that GLI2 may function in mediating gemcitabine sensitivity and that GLI2 was involved in the promotion of fibrosis in a mouse xenograft model. Immunohistochemical staining of 66 surgically resected GBC tissues revealed that GLI2­high expression patients had fewer numbers of CD3+ and CD8+ tumor­infiltrating lymphocytes (TILs) and increased programmed cell death ligand 1 (PD­L1) expression in cancer cells. These results suggest that GLI2, but not GLI1 or GLI3, is involved in proliferation, invasion, fibrosis, PD­L1 expression, and TILs in GBC and could be a novel therapeutic target. The results of this study provide a significant contribution to the development of a new treatment for refractory GBC, which has few therapeutic options.

NFκB and TGFß contribute to the expression of PTPN3 in activated human lymphocytes.

We previously reported that protein tyrosine phosphatase non-receptor type 3 (PTPN3), which is upregulated in activated lymphocytes, acts as an immune checkpoint. However, the mechanism by which PTPN3 expression is enhanced in activated lymphocytes is unknown. In this study, we analyzed the mechanism of PTPN3 expression in activated lymphocytes with a view for developing a novel immune checkpoint inhibitor that suppresses PTPN3. Through the activation process, lymphocytes showed enhanced NFκB activation as well as increased PTPN3 expression. NFκB enhanced proliferation, migration, and cytotoxicity of lymphocytes. Furthermore, NFκB enhanced PTPN3 expression and tyrosine kinase activation. TGFß reduced PTPN3 expression and NFκB activation in the cancer microenvironment, and suppressed the biological activity of lymphocytes. The results of this study are expected to provide significant implications for improving existing immunotherapy and developing novel immunotherapy.

FAM115C could be a novel tumor suppressor associated with prolonged survival in pancreatic cancer patients.

Hypoxia is a characteristic feature of the tumor microenvironment in pancreatic ductal adenocarcinoma (PDAC). We have recently explored new targeting molecules and pathways in PDAC cells under hypoxic conditions. In this study, we performed a microarray experiment to analyze the genes up-regulated in PDAC cell lines under hypoxia compared to normoxia, and identified human family with sequence similarity 115, member C (FAM115C) as a candidate gene for further study. Our data showed that FAM115C was overexpressed in PDAC cell lines under hypoxia, and FAM115C inhibition promoted PDAC cell migration and invasion in vitro. FAM115C inhibition did not affect tumor cell proliferation in PDAC. Immunohistochemically, FAM115C expression was observed ubiquitously in normal pancreas, pancreatic intraepithelial neoplasia (PanIN) and PDAC tissue, and it was located mainly in the nucleus but also in the cytoplasm of cells. In qPCR analysis, high expression of FAM115C was correlated with better prognosis in patients with PDAC. Our findings suggest that FAM115C could be a novel tumor suppressor associated with prolonged survival in patients with PDAC.

Patched 1-interacting Peptide Represses Fibrosis in Pancreatic Cancer to Augment the Effectiveness of Immunotherapy.

Pancreatic ductal adenocarcinoma (PDAC) is resistant to immunotherapy. As a factor of resistance, the dense fibrosis of this cancer acts as a barrier to inhibit immune cell infiltration into a tumor. We examined the influence of a Hedgehog signal inhibitor, Patched 1-interacting peptide, on fibrosis, infiltration of immune cells, and immunotherapeutic effects on PDAC. We found that this peptide inhibited proliferation and migration of cancer-associated fibroblasts and cancer cells. Furthermore, this peptide reduced the production of extracellular matrix and transforming growth factor ß1 in cancer-associated fibroblasts and induced expression of HLA-ABC in PDAC cells and interferon-γ in lymphocytes. In vivo, the peptide suppressed fibrosis of PDAC and increased immune cell infiltration into tumors. The combination of this peptide and an anti-programmed death-1 antibody augmented the antitumor effect, and this combination showed the same effect in experiments using cancer cells and autologous lymphocytes. These results indicate that, in addition to the direct effect of tumor suppression, the Patched 1-interacting peptide increases the infiltration of immune cells by reducing fibrosis of PDAC and consequently enhances the effect of immunotherapy. Therefore, treatment with this peptide may be a novel therapy with 2 different mechanisms: direct tumor suppression and enhancing the immune response against PDAC.

PTPN3 expressed in activated T lymphocytes is a candidate for a non-antibody-type immune checkpoint inhibitor.

It has been shown that protein tyrosine phosphatase non-receptor type (PTPN) 3 inhibits T-cell activation. However, there is no definitive conclusion about how the inhibition of PTPN3 in lymphocytes affects immune functions in human lymphocytes. In the present study, we showed that PTPN3 inhibition significantly contributes to the enhanced activation of activated human lymphocytes. The PTPN3 expression of lymphocytes was significantly increased through the activation process using IL-2 and anti-CD3 mAb. Interestingly, inhibiting the PTPN3 expression in activated lymphocytes significantly augmented the proliferation, migration, and cytotoxicity through the phosphorylation of zeta-chain-associated protein kinase 70 (ZAP-70), lymphocyte-specific protein tyrosine kinase (LCK), and extracellular signal-regulated kinases (ERK). Lymphocyte activation by PTPN3 inhibition was observed only in activated CD3+ T cells and not in NK cells or resting T cells. In therapy experiments using autologous tumors and lymphocytes, PTPN3 inhibition significantly augmented the number of tumor-infiltrated lymphocytes and the cytotoxicity of activated lymphocytes. Our results strongly imply that PTPN3 acts as an immune checkpoint in activated lymphocytes and that PTPN3 inhibitor may be a new non-antibody-type immune checkpoint inhibitor for cancer therapy.

The Novel Selective Pan-TRK Inhibitor ONO-7579 Exhibits Antitumor Efficacy Against Human Gallbladder Cancer In Vitro.

We previously reported that brain-derived neurotrophic factor (BDNF)/neurotrophic receptor tyrosine kinase 2 (NTRK2/TRKB) signaling contributes to induction of malignant phenotype of gallbladder cancer (GBC). Recently, pan-TRK inhibitors have been evaluated and their dramatic clinical activity is being shown for a variety of cancer types harboring an NTRK rearrangement in phase I trials. ONO-7579 is an oral pan-TRK inhibitor currently under investigation in phase I/II clinical trial for TRK-rearranged solid tumors. In this study, we evaluated the anticancer effect of ONO-7579 using GBC cells with or without KRAS mutant, NOZ, TYGBK-1. Our study showed that ONO-7579 had a suppressive effect on GBC proliferation in TYGBK-1, and on invasive potential and vascular endothelial growth factor expression in TYGBK-1 and NOZ. Our data indicated that ONO-7579 could be a promising treatment option for patients with GBC.

Liprin-α4 as a Possible New Therapeutic Target for Pancreatic Cancer.

BACKGROUND/AIM: In pancreatic cancer, where the microenvironment is extremely hypoxic, analyzing signal transduction under hypoxia is thought to be significantly important. By investigating microarray analysis of pancreatic cancer cells cultured under both normoxia and hypoxia, we found that the expression of leukocyte common antigen-related (LAR)-interacting protein (liprin)-α4 was extremely increased under hypoxia compared to under normoxia. MATERIALS AND METHODS: In the present study, the biological significance of liprin-α4 in pancreatic cancer was investigated and whether liprin-α4 has potential as a therapeutic target for pancreatic cancer was estimated. RESULTS: Suppression of liprin-α4 reduced proliferation of pancreatic cancer cells both in vitro and in vivo. Inhibition of liprin-α4 also reduced invasiveness through the suppression of endothelial-mesenchymal transition. Stimulation by liprin-α4 was through phosphoinositide 3-kinase and mitogen-activated protein kinase signaling pathways. CONCLUSION: Liprin-α4 plays a pivotal role in inducing malignant phenotypes such as increased proliferation and invasion in pancreatic cancer, and that liprin-α4 could be a new effective therapeutic target for pancreatic cancer.

CD24 Modulates Chemosensitivity of MCF-7 Breast Cancer Cells.

The role of cluster of differentiation (CD) 24 in breast cancer remains unclear; previously, we showed that CD24 suppresses malignant phenotypes by inactivating Hedgehog signaling through signal transducer and activator of transcription (STAT) 1 inhibition. In this study, we examined how CD24 affects chemosensitivity in breast cancer cells. The CD44+CD24+ breast cancer cell line MCF-7 was transfected with CD24 with/without STAT1 siRNA, and chemosensitivity to 5-fluorouracil (5-FU) and cis-diamminedichloroplatinum (CDDP) was measured. CD24 inhibition reduced chemosensitivity to 5-FU, while STAT1 inhibition did not affect chemosensitivity to 5-FU in CD24 siRNA-transfected cells. Conversely, CD24 inhibition did not affect chemosensitivity to CDDP, while STAT1 inhibition reduced chemosensitivity to CDDP in CD24 siRNA-transfected cells. STAT1 inhibition, but not CD24 inhibition, reduced expression of the ATP-binding cassette (ABC) transporter genes, ABCB1 and ABCG2. In conclusion, CD24 inhibition may modulate chemosensitivity according to drug type, but ABC transporter expression appears not to contribute to this mechanism. This study contributes to determining the role of CD24 in breast cancer.

Hedgehog signaling regulates PDL-1 expression in cancer cells to induce anti-tumor activity by activated lymphocytes.

We investigated whether hypoxia-induced activation of Hh signaling contributes to PDL-1 expression in cancer and whether it affects the anti-tumor function of activated lymphocytes. Hypoxia augmented PDL-1 expression and inhibition of Hh signaling reduced PDL-1 expression under hypoxia. When activated lymphocytes were cocultured with cancers treated with a Hh inhibitor, activated lymphocyte cell numbers increased under hypoxia. In contrast, this increase was abrogated when cancer cells were treated with a PDL-1 neutralizing antibody. These results suggest that Hh signaling is one of regulatory pathways of PDL-1 expression under hypoxia and that inhibiting Hh signaling may induce lymphocyte anti-tumor activity.

Protein-bound Polysaccharide-K Inhibits Hedgehog Signaling Through Down-regulation of MAML3 and RBPJ Transcription Under Hypoxia, Suppressing the Malignant Phenotype in Pancreatic Cancer.

Hedgehog signaling is activated in pancreatic cancer and could be a therapeutic target. We previously demonstrated that recombination signal binding protein for immunoglobulin-kappa-J region (RBPJ) and mastermind-like 3 (MAML3) contribute to the hypoxia-induced up-regulation of Smoothened (SMO) transcription. We have also shown that protein-bound polysaccharide-K (PSK) could be effective for refractory pancreatic cancer that down-regulates SMO transcription under hypoxia. In this study, we evaluated whether the anticancer mechanism of PSK involves inhibiting RBPJ and MAML3 expression under hypoxia. PSK reduced SMO, MAML3 and RBPJ expression in pancreatic cancer cells under hypoxia. PSK also blocked RBPJ-induced invasiveness under hypoxia by inhibiting matrix metalloproteinase expression. Lastly, we showed that PSK attenuated RBPJ-induced proliferation both in vitro and in vivo. These results suggest that PSK suppresses Hedgehog signaling through down-regulation of MAML3 and RBPJ transcription under hypoxia, inhibiting the induction of a malignant phenotype in pancreatic cancer. Our results may lead to development of new treatments for refractory pancreatic cancer using PSK as a Hedgehog inhibitor.

A Cross-Cultural Study on Behaviors When Death Is Approaching in East Asian Countries: What Are the Physician-Perceived Common Beliefs and Practices?

The primary aim of this study was to explore common beliefs and practices when death is approaching in East-Asian countries. A cross-sectional survey was performed involving palliative care physicians in Japan, Korea, and Taiwan. Measurement outcomes were physician-perceived frequencies of the following when patient death was approaching: (1) reluctance to take part in end-of-life discussions, (2) role of family members, (3) home death, and (4) circumstances surrounding death. A total of 505, 211, and 207 responses were obtained from Japanese, Korea, and Taiwan physicians, respectively. While 50% of the Japanese physicians reported that they often or very often experienced families as being reluctant to discuss end-of-life issues, the corresponding figures were 59% in Korea and 70% in Taiwan. Two specific reasons to avoid end-of-life discussion, "bad things happen after you say them out loud" and "a bad life is better than a good death" were significantly more frequently observed in Taiwan. Prioritizing the oldest of the family in breaking bad news and having all family members present at the time of death were significantly more frequently observed in Korea and Taiwan. Half of Taiwanese physicians reported they often or very often experienced the patients/family wanted to go back home to die because the soul would not be able to return from the hospital. In all countries, more than 70% of the physicians reported certain family members were expected to care for the patient at home. At the time of death, while no Japanese physicians stated that they often experienced patients wanted a religious person to visit, the corresponding figure in Korean and Taiwan was about 40%. Uncovered expression of emotion was significantly frequently observed in Korean and Taiwan, and 42% of the Japanese physicians reported family members cleaned the dead body of the patient themselves. There seem to be significant intercountry differences in beliefs and practices when death is approaching in East Asian countries. Future studies on direct observations of patients and families are needed.

Palliative Care Physicians' Attitudes Toward Patient Autonomy and a Good Death in East Asian Countries.

CONTEXT: Clarification of the potential differences in end-of-life care among East Asian countries is necessary to provide palliative care that is individualized for each patient. OBJECTIVES: The aim was to explore the differences in attitude toward patient autonomy and a good death among East Asian palliative care physicians. METHODS: A cross-sectional survey was performed involving palliative care physicians in Japan, Taiwan, and Korea. Physicians' attitudes toward patient autonomy and physician-perceived good death were assessed. RESULTS: A total of 505, 207, and 211 responses were obtained from Japanese, Taiwanese, and Korean physicians, respectively. Japanese (82%) and Taiwanese (93%) physicians were significantly more likely to agree that the patient should be informed first of a serious medical condition than Korean physicians (74%). Moreover, 41% and 49% of Korean and Taiwanese physicians agreed that the family should be told first, respectively; whereas 7.4% of Japanese physicians agreed. Physicians' attitudes with respect to patient autonomy were significantly correlated with the country (Japan), male sex, physician specialties of surgery and oncology, longer clinical experience, and physicians having no religion but a specific philosophy. In all 12 components of a good death, there were significant differences by country. Japanese physicians regarded physical comfort and autonomy as significantly more important and regarded preparation, religion, not being a burden to others, receiving maximum treatment, and dying at home as less important. Taiwanese physicians regarded life completion and being free from tubes and machines as significantly more important. Korean physicians regarded being cognitively intact as significantly more important. CONCLUSION: There are considerable intercountry differences in physicians' attitudes toward autonomy and physician-perceived good death. East Asia is not culturally the same; thus, palliative care should be provided in a culturally acceptable manner for each country.

Biomagnetic measurement system for supine subjects with expanded sensor array and real-time noise reduction.

A biomagnetic measurement system was developed, suitable for the detection of magnetospinogram (MSG) and magnetocardiogram (MCG) signals from the dorsal surface of supine subjects. It is effective for noninvasively observing the electric activity of the spinal cord and/or heart. These biomagnetic signals are extremely weak, and magnetic flux sensors based on superconducting quantum interference devices (SQUIDs) are necessary to detect them. However, highly sensitive magnetic field measurement often suffers from ultra low-band circumstance noise mainly caused by transportation in urban areas. We applied reference sensors for monitoring the circumstance noise, and their outputs multiplied by appropriate weight coefficients were directly input to the feedback coil of a SQUID gradiometer. Synthesized in-phase components reduced the ultra low-band noise by approximately 90%. Both the MSG and MCG signals were successfully detected in a moderately magnetically shielded room. Even though the MCG signal band overlapped the ultra low-band noise, the signal-to-noise ratio was improved.