Development of a Water Soluble Self-assembling Analogue of Vizantin

Vizantin, 6,6'-bis-O-(3-nonyldodecanoyl)-α,α'-trehalose, has been developed as a safe immunostimulator on the basis of a structure-activity relationship study with trehalose 6,6'-dicorynomycolate. Our recent study indicated that vizantin acts as an effective Toll-like receptor-4 (TLR4) partial agonist to reduce the lethality of an immune shock caused by lipopolysaccharide (LPS). However, because vizantin has low solubility in water, the aqueous solution used in in vivo assay systems settles out in tens of minutes. Here, vizantin was chemically modified in an attempt to facilitate the preparation of an aqueous solution of the drug. This paper describes the concise synthesis of a water-soluble vizantin analogue in which all the hydroxyl groups of the sugar unit were replaced by sulfates. The vizantin derivative displayed micelle-forming ability in water and potent TLR-4 partial agonist activity.

Laparoscopic Colorectal Cancer Surgery for Patients With Severe Chronic Heart Failure

BACKGROUND/AIM

Laparoscopic surgery with pneumoperitoneum is not usually recommended for patients with heart failure due to the potential risks associated with cardiopulmonary stress. Few studies, however, have directly examined whether a laparoscopic approach can be used safely in patients with severe chronic heart failure.

PATIENTS AND METHODS

We retrospectively evaluated the safety and feasibility of laparoscopic colorectal cancer surgery in 13 patients with severe chronic heart failure, defined as left ventricular ejection fraction <40% and/or brain natriuretic peptide >100 pg/ml (NT-proBNP >400 pg/ml). Intraoperative hemodynamics, including systolic blood pressure, diastolic blood pressure, mean blood pressure, and heart rate, were carefully monitored.

RESULTS

The median left ventricular ejection fraction value was 35% (18-62%), and the median brain natriuretic peptide value was 171.7 pg/ml (109.5-961.4 pg/ml). The time-series mean ratio of the patients' blood pressure and heart rate during surgery indicated that soon after the induction of general anesthesia, mean blood pressure was significantly decreased (p<0.05) from baseline. In all 13 cases, laparoscopic surgery was performed successfully, with no significant complications.

CONCLUSION

The present study showed that laparoscopic surgery for colorectal cancer can be performed safely in patients with severe chronic heart failure.

A quantitative evaluation method utilizing the homology concept to assess the state of chromatin within the nucleus of lung cancer

Homology is a mathematical tool to quantify "the contact degree", which can be expressed in terms of Betti numbers. The Betti numbers used in this study consisted of two numbers, b0 (a zero-dimensional Betti number) and b1 (a one-dimensional Betti number). We developed a chromatin homology profile (CHP) method to quantify the chromatin contact degree based on this mathematical tool. Using the CHP method we analyzed the number of holes (surrounded areas = b1 value) formed by the chromatin contact and calculated the maximum value of b1 (b1MAX), the value of b1 exceeding 5 for the first time or Homology Value (HV), and the chromatin density (b1MAX/ns2). We attempted to detect differences in chromatin patterns and differentiate histological types of lung cancer from respiratory cytology using these three features. The HV of cancer cells was significantly lower than that of non-cancerous cells. Furthermore, b1MAX and b1MAX/ns2 showed significant differences between small cell and non-small cell carcinomas and between adenocarcinomas and squamous cell carcinomas, respectively. We quantitatively analyzed the chromatin patterns using homology and showed that the CHP method may be a useful tool for differentiating histological types of lung cancer in respiratory cytology.

High Level Sacral Bone Resection for Locally Recurrent Rectal Cancer

BACKGROUND/AIM

Locally recurrent rectal cancer (LRRC) involving the upper sacrum is generally considered a contraindication for curative surgery. In the surgical management of LRRC, sacrectomy is frequently performed to secure clear resection margins. Nonetheless, the indications for high sacrectomy remain controversial due to potential postoperative complications, questions about radicality, and the increased complexity of the operation. Furthermore, comprehensive studies addressing this issue are notably absent. This study aimed to assess the feasibility, safety, and surgical prognosis in high sacrectomy for LRRC.

PATIENTS AND METHODS

All patients with LRRC who required concomitant sacrectomy, but did not include the inferior margin of the second sacral vertebra, between 2003 and 2014, were reviewed retrospectively.

RESULTS

Eight patients with a median age of 59 years were included in this study. The proximal resection line for sacral bone resection was the central part of the S1 vertebra in one patient, lower edge of the S1 vertebra in six patients, and central part of the S2 vertebra in one patient. Negative margin resection was achieved in five out of the eight patients. The median operative time was 922 min, and the median operative blood loss volume was 6,370 ml. Major complications included pelvic abscess (n=5), ileus (n=1), and pulmonary vein embolism (n=1), none of which proved fatal during the postoperative period. Both the 5-year local re-recurrence-free survival rate and the 5-year distant metastasis-free survival rate were 50% (4/8).

CONCLUSION

High sacrectomy is safe and feasible to achieve negative margins in patients with LRRC.

Treatment response prediction of neoadjuvant chemotherapy for rectal cancer by deep learning of colonoscopy images

In current clinical practice, several treatment methods, including neoadjuvant therapy, are being developed to improve overall survival or local recurrence rates for locally advanced rectal cancer. The response to neoadjuvant therapy is usually evaluated using imaging data collected before and after preoperative treatment or postsurgical pathological diagnosis. However, there is a need to accurately predict the response to preoperative treatment before treatment is administered. The present study used a deep learning network to examine colonoscopy images and construct a model to predict the response of rectal cancer to neoadjuvant chemotherapy. A total of 53 patients who underwent preoperative chemotherapy followed by radical resection for advanced rectal cancer at the Osaka University Hospital between January 2011 and August 2019 were retrospectively analyzed. A convolutional neural network model was constructed using 403 images from 43 patients as the learning set. The diagnostic accuracy of the deep learning model was evaluated using 84 images from 10 patients as the validation set. The model demonstrated a sensitivity, specificity, accuracy, positive predictive value and area under the curve of 77.6% (38/49), 62.9% (22/33), 71.4% (60/84), 74.5% (38/51) and 0.713, respectively, in predicting a poor response to neoadjuvant therapy. Overall, deep learning of colonoscopy images may contribute to an accurate prediction of the response of rectal cancer to neoadjuvant chemotherapy.

Cancer Stem Cells Persist Despite Cellular Damage, Emergence of the Refractory Cell Population

PURPOSE

Cancer stem cells (CSCs) are responsible for chemotherapy resistance and have unique properties that protect them from chemotherapy. Investigating CSCs may help to identify the population that is more resistant to treatments, leading to recurrence. We evaluated persisting CSCs, emerging after chemotherapy that cause tumor recurrence.

METHODS

Using human colorectal cancer organoids prepared from surgical specimens, we looked at changes in CSCs, the emergence and changes in the original population, which single-cell analysis identified.

RESULTS

With regards to changes in cancer stem cell markers, CD44 showed low levels after 5-fluorouracil administration. Once the CD44-ve population was sorted and cultured, the CD44+ve population gradually emerged, and the CD44-ve population decreased. Compared with the CD44-ve population of an organoid parent, the CD44-ve population proliferated after chemotherapeutic agent stimulation. The CD44-ve population was derived from the CD44+ve population before chemotherapeutic agents. In addition, when the CD44 variants were evaluated, the CD44v9 population remained. In single-cell analysis, we found that POU5F1 was highly expressed in the CD44low population. Velocity analysis showed that the CD44-ve population was induced after chemotherapy and expressed POU5F1. POU5F1-EGFP-Casp9 transfected organoids resulted in the appearance of a CD44-ve population after administration of a chemotherapeutic reagent. Both in vivo and in vitro, the dimerizer administration inhibited tumor growth significantly.

CONCLUSIONS

POU5F1 is involved in chemotherapy resistance in relation to stemness. For the treatment against refractory tumors, such as the recurrence after chemotherapy, the treatment should target the emerging specific population such as CD44 (or CD44v9) and proliferative cancer cells.

Surgery for Rectal Cancer With Mixed Reality of 3D Model During Operation: A Case Report

Background/Aim

Recently, robotic surgery for rectal cancer has become a common minimally invasive surgery. In addition, the technology of augmented and mixed reality is applied in various living environments, including medicine. We successfully performed robotic surgery for rectal cancer with three-dimensional (3D) images as mixed reality (MR) using HoloLens2.

Case Report

The patient was diagnosed with rectal cancer by colonoscopy and a positron-emission computed-tomography scan, and we performed robot-assisted anterior resection. The operator used HoloLens2 and performed the surgery while visualizing 3D images of pelvic anatomy with the location of the rectal cancer as hologram. The operation was performed completely and safely, and she was discharged 11 days after surgery with no postoperative complications.

Conclusion

This case presents the usefulness of a MR system offering organ visualization as hologram during surgery.

The Clinical Potential of FBPA-PET/CT Imaging for Colorectal Cancer and its Liver Metastases Expressing LAT1

BACKGROUND/AIM

18F-fluoro-deoxy-glucose positron emission tomography (18F-FDG PET) has become indispensable for staging colorectal cancer but has limitations. Thus, PET with a focus on metabolism other than glucose, mainly amino acid metabolism, has been developed. L-type amino acid transporter 1 (LAT1) is known to be a cancer-specific amino acid transporter and, although 4-Borono-2-(18)F-fluoro-phenylalanine (FBPA) has been reported to be useful as a probe for LAT1, the significance of LAT1 expression in colorectal cancer is ambiguous and implementation of 18F-FBPA-PET in colorectal cancer has not yet been reported.

MATERIALS AND METHODS

The aims of this study were to investigate the expression of LAT1 in primary lesions and metastatic lesions of colorectal cancer by immunohistochemical analysis and report the initial experience of performing 18F-FBPA-PET on colorectal cancer patients in clinical practice.

RESULTS

There was a significant correlation between LAT1 protein expression in primary tumors and liver metastases. Furthermore LAT-1 expression was positively correlated with recurrence (p=0.033). We performed 18F-FBPA-PET on three rectal cancer patients and detected cancer.

CONCLUSION

LAT1 protein is expressed not only in the primary colorectal tumor, but also in liver metastases. 18F-FBPA-PET can be safely performed in patients with colorectal cancer.

A Case of Rectal Cancer with Vaginal Invasion Using Indocyanine Green to Determine the Extent of Resection

Here we report a case of locally advanced rectal cancer with vaginal invasion, which was successfully resected via laparoscopic surgery using intraoperative indocyanine green (ICG) navigation to determine the vaginal cut line. Based on preoperative examinations, an 81-year-old female was diagnosed with locally advanced rectal cancer with vaginal invasion. After preoperative chemoradiotherapy, the lesion was judged to be resectable. During surgery, the gynecologist transvaginally injected ICG into the vaginal submucosa to determine the caudal margin of the vaginal invasion, and laparoscopically dissected under the near-infrared image of the stained area. Pathological analysis of the resection specimen revealed negative resection margins. One year after surgery, there has been no recurrence.

Testicular metastasis 9 years after resection of primary descending colon cancer with simultaneous pulmonary metastasis: a case report

BACKGROUND

Metastatic testicular cancer is rare. In particular, primary colorectal cancer rarely metastasizes to the testes. This study reports a case of testicular metastasis recurrence 9 years after the resection of a primary colorectal cancer and a simultaneous metastatic lung tumour.

CASE PRESENTATION

A 69-year-old man underwent a laparoscopic left hemicolectomy for descending colon cancer. Preoperative computed tomography revealed a solitary left lung mass. Postoperative chemotherapy reduced the size of the lung mass, and 6 months after the primary resection, the patient underwent a left upper segmentectomy. Based on the pathological examination, he was diagnosed with pulmonary metastasis from colorectal cancer. After four courses of adjuvant chemotherapy, the patient was recurrence-free. However, 9 years and 6 months after the primary resection, he complained of discomfort in his left testicle. Physical examination revealed a left testicular mass. Since a malignancy was not excluded via imaging, left testicular resection was performed to confirm the diagnosis. The pathological diagnosis was testicular metastasis from colorectal cancer. The patient was followed up without medication, and remained healthy, without recurrence, 11 months postoperatively.

CONCLUSIONS

It is important to follow up with testicular metastasis in mind, although it is rare.

Lymph node metastasis in T1 colorectal cancer: Risk factors and prediction model

Endoscopic resection is typically performed for early T1 stage colorectal cancer (T1 CRC). Additional surgery is subsequently recommended based on pathological findings; however, the current criteria may result in overtreatment. The present study aimed to re-examine the reported risk factors for lymph node (LN) metastasis in T1 CRC and develop a prediction model using a large multi-institutional dataset. In this retrospective study, the medical records of 1,185 patients with T1 CRC who underwent surgery between January 2008 and December 2020 were investigated. Slides pathologically re-assessable for additional risk factors were re-examined. A total of 251 patients with inadequate data were excluded, and 934 patients were randomly assigned at a ratio of 3:1 to the training and validation datasets. In the univariate analysis, left-sided CRC (P=0.003), deep submucosal invasion depth (P=0.005), poor histological grade (P=0.020), lymphatic invasion (P<0.001), venous invasion (P<0.001) and tumor budding grade 2/3 (P<0.001) were significant risk factors for LN metastasis. A nomogram predicting LN metastasis was developed using these variables, with an area under the received operating characteristic curve (AUC) of 0.786. The nomogram was validated using a validation set with an AUC of 0.721, indicating moderate accuracy. No LN metastases were observed in patients with <90 points using the nomogram; therefore, patients with a low nomogram score may avoid undergoing surgical resection. Prediction of LN metastasis using this developed nomogram may help identify patients who are at high-risk who require surgery.

Machine learning-based model for prediction and feature analysis of recurrence in pancreatic neuroendocrine tumors G1/G2

BACKGROUND

Pancreatic neuroendocrine neoplasms (PanNENs) are a heterogeneous group of tumors. Although the prognosis of resected PanNENs is generally considered to be good, a relatively high recurrence rate has been reported. Given the scarcity of large-scale reports about PanNEN recurrence due to their rarity, we aimed to identify the predictors for recurrence in patients with resected PanNENs to improve prognosis.

METHODS

We established a multicenter database of 573 patients with PanNENs, who underwent resection between January 1987 and July 2020 at 22 Japanese centers, mainly in the Kyushu region. We evaluated the clinical characteristics of 371 patients with localized non-functioning pancreatic neuroendocrine tumors (G1/G2). We also constructed a machine learning-based prediction model to analyze the important features to determine recurrence.

RESULTS

Fifty-two patients experienced recurrence (14.0%) during the follow-up period, with the median time of recurrence being 33.7 months. The random survival forest (RSF) model showed better predictive performance than the Cox proportional hazards regression model in terms of the Harrell's C-index (0.841 vs. 0.820). The Ki-67 index, residual tumor, WHO grade, tumor size, and lymph node metastasis were the top five predictors in the RSF model; tumor size above 20 mm was the watershed with increased recurrence probability, whereas the 5-year disease-free survival rate decreased linearly as the Ki-67 index increased.

CONCLUSIONS

Our study revealed the characteristics of resected PanNENs in real-world clinical practice. Machine learning techniques can be powerful analytical tools that provide new insights into the relationship between the Ki-67 index or tumor size and recurrence.

Tumor-suppressive role of the musculoaponeurotic fibrosarcoma gene in colorectal cancer

Somatic cell reprogramming using the microRNAs miR-200c, miR-302s, and miR-369s leads to increased expression of cyclin-dependent kinase inhibitors in human colorectal cancer (CRC) cells and suppressed tumor growth. Here, we investigated whether these microRNAs inhibit colorectal tumorigenesis in CPC;Apc mice, which are prone to colon and rectal polyps. Repeated administration of microRNAs inhibited polyp formation. Microarray analysis indicated that c-MAF, which reportedly shows oncogene-like behavior in multiple myeloma and T cell lymphoma, decreased in tumor samples but increased in microRNA-treated normal mucosa. Immunohistochemistry identified downregulation of c-MAF as an early tumorigenesis event in CRC, with low c-MAF expression associated with poor prognosis. Of note, c-MAF expression and p53 protein levels were inversely correlated in CRC samples. c-MAF knockout led to enhanced tumor formation in azoxymethane/dextran sodium sulfate-treated mice, with activation of cancer-promoting genes. c-MAF may play a tumor-suppressive role in CRC development.

Super Carbonate Apatite-miR-497a-5p Complex Is a Promising Therapeutic Option against Inflammatory Bowel Disease

The incidence of inflammatory bowel disease (IBD) is increasing worldwide. It is reported that TGF-β/Smad signal pathway is inactivated in patients with Crohn's disease by overexpression of Smad 7. With expectation of multiple molecular targeting by microRNAs (miRNAs), we currently attempted to identify certain miRNAs that activate TGF-β/Smad signal pathway and aimed to prove in vivo therapeutic efficacy in mouse model. Through Smad binding element (SBE) reporter assays, we focused on miR-497a-5p. This miRNA is common between mouse and human species and enhanced the activity of TGF-β/Smad signal pathway, decreased Smad 7 and/or increased phosphorylated Smad 3 expression in non-tumor cell line HEK293, colorectal cancer cell line HCT116 and mouse macrophage J774a.1 cells. MiR-497a-5p also suppressed the production of inflammatory cytokines TNF-α, IL-12p40, a subunit of IL-23, and IL-6 when J774a.1 cells were stimulated by lipopolysaccharides (LPS). In a long-term therapeutic model for mouse dextran sodium sulfate (DSS)-induced colitis, systemic delivery of miR-497a-5p load on super carbonate apatite (sCA) nanoparticle as a vehicle restored epithelial structure of the colonic mucosa and suppressed bowel inflammation compared with negative control miRNA treatment. Our data suggest that sCA-miR-497a-5p may potentially have a therapeutic ability against IBD although further investigation is essential.

Abstract 2698: Improved calcium phosphate delivery system cNaD to aim clinical application

Super carbonate apatite (sCA) nanoparticle is a superb calcium phosphate delivery system for miRNA and siRNA to tumors (PlosOne 2015). We reported that sCA delivered efficiently siRNA for survivin and PTBP as well as miR-340 (Mol Cancer Ther 2015, 2015) to colon tumors implanted into nude mice. MiR-4689 and miR-29b-1-5p suppressed KRAS mutated colon cancer cells (Mol Ther NA2015, 2018) and miR-302 and miR-369 realized in vivo cancer reprograming (PlosOne 2015). In every case the RNA function was fully realized. Moreover, effect of influenza vaccination was augmented by sCA plus CpG nucleic acid (NA) (Frontiers in Immunol 2018). sCA coupled with miR-29a or miR-29b prevented the DSS (dextran sodium sulfate)-induced inflammatory bowel disease (Mol Ther NA2018). We also applied the sCA-ICG complex to minimally invasive treatment of photodynamic therapy (Mol Cancer Ther 2018). Following these outstanding findings, we tried and succeeded to establish a clinically available novel calcium phosphate delivery system, named cNaD, which controls the nano-particle size and avoids accumulation in normal organs including liver and spleen. It is characterized by its ability to efficiently deliver siRNA and microRNA to cancers and provided prominent therapeutic effect in various mouse models. Safety test has been accomplished in rats and monkeys based on GLP standards. Also, the scale-up manufacturing system &gt;1000 folds has been attained. Our cNaD system will accelerate the development of NA medicine in the world.

Citation Format: Hirofumi Yamamoto. Improved calcium phosphate delivery system cNaD to aim clinical application [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2698.

Abstract 5855: Spatial transcriptomics deciphers the cellular society of advanced colorectal cancer

Introduction: In recent years, single-cell RNA sequencing (scRNA-seq) and high-dimensional spatial transcriptomics (ST-seq) have contributed significantly to our understanding of the tumor microenvironment (TME) in many cancers. This is essential for understanding the tumor-stromal crosstalk. Thus, integrating scRNA-seq data with ST-seq data will facilitate understanding intercellular communication in TMEs.

Material and Method: We performed and combined ST-seq in CRC with public scRNA-seq. And, immunohistochemistry (IHC) (HLA-G, CD68, and SPP1) was performed on 20 CRC surgical specimens collected in our hospital. To verify this, we knocked out H2-M3 (HLA-G in humans) in mouse CRC cell lines (MC-38 cells) using the CRISPR/Cas9 system and examined H2-M3 KO tumor volume in xenograft mouse models.

Results: We identified co-localized cells with CRC cells at the invasive front and those in the center based on the spatial distribution estimated by an analytical pipeline, Cell2location. At the invasive front, CRC cells co-localized more frequently with SPP1+ macrophages than other cells. To dissect the molecular machinery and cell types inducing SPP1+ macrophages, we found ligand activity by another pipeline, NicheNet. The prominent signal to SPP1+ macrophages was mediated by several ligand-receptor pairs including HLA-G- immunoglobulin-like transcript (ILT)2/ILT4. Next, we disclosed the effect on CD8+ cells, and SPP1+ macrophages secrete IL-10 suppressing the immune activity of CD8+ T cells. And the ratio of HLA-G-positive cancer cells was predominantly higher in areas with more SPP1+ macrophages by IHC in CRC. In vivo analysis, H2-M3 KO reduced CRC tumor volume and tumor tissue from H2-M3 KO cells exhibited higher SPP1 and CD68 staining compared with wild type cells.

Conclusion: SPP1+ macrophages and cancer cells secreting high levels of HLA-G may represent targets to improve the prognosis of patients with CRC. Further analysis is currently underway with a focus on early-stage cancer in carcinoma in adenoma.

Citation Format: Masahiro Hashimoto, Yuki Ozato, Yusuke Nakano, Tadashi Abe, Yuichi Hisamastu, Takeo Toshima, Yusuke Yonemura, Mamoru Uemura, Takaaki Masuda, Hirofumi Yamamoto, Masaki Mori, Hidetoshi Eguchi, Yuichiro Doki, Koshi Mimori. Spatial transcriptomics deciphers the cellular society of advanced colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5855.

KRT13 is upregulated in pancreatic cancer stem-like cells and associated with radioresistance

Pancreatic cancer is one of the most aggressive cancers and the seventh leading cause of cancer-associated death in the world. Radiation is performed as an adjuvant therapy as well as anti-cancer drugs. Because cancer stem-like cells (CSCs) are considered to be radioresistant and cause recurrence and metastasis, understanding their properties is required for the development of novel therapeutic strategies. To investigate the CSC properties of pancreatic cancer cells, we used a pancreatic CSC model, degron (++) cells, which have low proteasome activity. Degron (++) cells displayed radioresistance in comparison with control cells. Using Ribonucleic acid (RNA) sequencing, we successfully identified KRT13 as a candidate gene responsible for radioresistance. Knockdown of KRT13 sensitized the degron (++) cells to radiation. Furthermore, a database search revealed that KRT13 is upregulated in pancreatic cancer cell lines and that high expression of KRT13 is associated with poorer prognosis. These results indicate that a combination therapy of KRT13 knockdown and radiation could hold therapeutic promise in pancreatic cancer.

The Relationship between LRP6 and Wnt/β-Catenin Pathway in Colorectal and Esophageal Cancer

High expression of low-density lipoprotein receptor-related protein 6 (LRP6), a key component of the Wnt/β-catenin signaling pathway, is reported to be associated with malignant potential in some solid tumors including breast cancer and hepatocellular carcinoma. Few reports, however, have examined its function and clinical significance in colorectal cancers (CRC) demonstrating constitutive activation of Wnt signaling. Here, we compared the expression level and function of LRP6 in CRC with that of esophageal squamous cell carcinoma (ESCC) bearing few Wnt/β-catenin pathway mutations. On immunohistochemical staining, high LRP6 expression was noted in three of 68 cases (4.4%), and high β-catenin in 38 of 67 cases (56.7%) of CRC. High LRP6 expression was found in 21 of 82 cases (25.6%), and high β-catenin expression in 29 of 73 cases (39.7%) of ESCC. In our in vitro studies, LRP6 knockdown hardly changed Wnt signaling activity in CRC cell lines with mutations in Wnt signaling downstream genes. In contrast, in ESCC cell lines without Wnt signaling-related mutations, LRP6 knockdown significantly decreased Wnt signaling activity. LRP6 function may depend on constitutive activation of Wnt signaling.

Single-Cell Analysis of Circulating Tumor Cells from Patients with Colorectal Cancer Captured with a Dielectrophoresis-Based Micropore System

This study aimed to analyze circulating tumor cells (CTCs) from patients with colorectal cancer (CRC). We designed a dielectrophoresis-based micropore system and tested its cell capture with HT29 colon cancer cells. Then, blood samples were drawn from 24 patients with stages II-IV CRC. Mononuclear cells were isolated and loaded into the micropore system. Single cells were positioned into small pores with dielectrophoresis. After labeling the cells with the appropriate antibodies, tumor-like cells were collected with an automated micromanipulator. We collected 43 CTCs from 15 out of 24 patient samples. The presence of CTC was significantly associated with ling metastasis. We performed whole genome amplification, followed by PCR and Sanger sequencing, to examine the point mutations in the KRAS, BRAF, and PIK3CA genes. This mutation analysis was successfully performed in 35 cells. Among the 14 cytokeratin (CK)-positive cells, we found PIK3CA mutations in three cells (21%) from two patients. Among the 21 CK-negative cells, we found a KRAS mutation in one cell (5%) from one patient and a PIK3CA mutation in one cell (5%) from one patient. It is noteworthy that these mutations were not detected in the corresponding primary tumors. In conclusion, dielectrophoresis-based capture in a micropore system was useful for detecting both CK-positive and CK-negative CTCs. This simple method could be applied to various tumor types.

TRPM8 promotes hepatocellular carcinoma progression by inducing SNORA55 mediated nuclear-mitochondrial communication

Transient receptor potential melastatin 8 (TRPM8) play crucial roles in solid tumors such as prostate and breast cancers. But the role of TRPM8 in hepatocellular carcinoma (HCC) and its underlying molecular mechanisms remain largely unknown. In this study, the functional roles of TRPM8 in HCC were systematically investigated for the first time. It was found that the expression level of TRPM8 was significantly upregulated in HCC, which was positively correlated with the worse clinicopathological characteristics. Functional studies revealed that pharmacological inhibition or genetic downregulation of TRPM8 ameliorated hepatocarcinogenesis in vitro and in vivo. Mechanistically, the oncogenic role of TRPM8 in HCC was at least partially achieved by affecting mitochondrial function. TRPM8 could modulate the expression of nucleolar relative molecule-small nucleolar RNA, H/ACA box 55 (SNORA55) by inducing transformation of chromatin structure and histone modification type. These data suggest that as a bridge molecule in TRPM8-triggered HCC, SNORA55 can migrate from nucleus to mitochondria and exert oncogenic role by affecting mitochondria function through targeting ATP5A1 and ATP5B. Herein, we uncovered the potent oncogenic role of TRPM8 in HCC by inducing nuclear and mitochondrial dysfunction in a SNORA55 dependent manner, and provided a potential therapeutic target for HCC.

TRPM8 contributes to liver regeneration via mitochondrial energy metabolism mediated by PGC1α

Impairment of liver regeneration leads to severe morbidity in acute and chronic severe liver disease. Transient receptor potential melastain 8 (TRPM8) is involved in a variety of processes, including temperature sensing, ion homeostasis, and cell proliferation. However, whether TRPM8 contributes to liver regeneration is still unclear. We assessed the effect and mechanism of TRPM8 in liver regeneration and hepatocyte proliferation in vivo and in vitro. In this study, we found that TRPM8 deficiency impairs liver regeneration in mice. Mechanistically, the results revealed that mitochondrial energy metabolism was attenuated in livers from TRPM8 knockout (KO) mice. Furthermore, we found that TRPM8 contributes to the proliferation of hepatocytes via PGC1α. Taken together, this study shows that TRPM8 contributes to liver regeneration in mice after hepatectomy. Genetic approaches and pharmacological approaches to regulate TRPM8 activity may be beneficial to the promotion of liver regeneration.

TRPM8 deficiency attenuates liver fibrosis through S100A9-HNF4α signaling

Background

Liver fibrosis represent a major global health care burden. Data emerging from recent advances suggest TRPM8, a member of the transient receptor potential (TRP) family of ion channels, plays an essential role in various chronic inflammatory diseases. However, its role in liver fibrosis remains unknown. Herein, we assessed the potential effect of TRPM8 in liver fibrosis.

Methods

The effect of TRPM8 was evaluated using specimens obtained from classic murine models of liver fibrosis, namely wild-type (WT) and TRPM8^−/− (KO) fibrotic mice after carbon tetrachloride (CCl₄) or bile duct ligation (BDL) treatment. The role of TRPM8 was systematically evaluated using specimens obtained from the aforementioned animal models after various in vivo and in vitro experiments.

Results

Clinicopathological analysis showed that TRPM8 expression was upregulated in tissue samples from cirrhosis patients and fibrotic mice. TRPM8 deficiency not only attenuated inflammation and fibrosis progression in mice but also helped to alleviate symptoms of cholangiopathies. Moreover, reduction in S100A9 and increase in HNF4α expressions were observed in liver of CCl₄- and BDL- treated TRPM8^−/− mice. A strong regulatory linkage between S100A9 and HNF4α was also noticed in L02 cells that underwent siRNA-mediated S100A9 knockdown and S100A9 overexpressing plasmid transfection. Lastly, the alleviative effect of a selective TRPM8 antagonist was confirmed in vivo.

Conclusions

These findings suggest TRPM8 deficiency may exert protective effects against inflammation, cholangiopathies, and fibrosis through S100A9-HNF4α signaling. M8-B might be a promising therapeutic candidate for liver fibrosis.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13578-022-00789-4.

Diagnosis of Depth of Submucosal Invasion in Colorectal Cancer with AI Using Deep Learning

The submucosal invasion depth predicts prognosis in early colorectal cancer. Although colorectal cancer with shallow submucosal invasion can be treated via endoscopic resection, colorectal cancer with deep submucosal invasion requires surgical colectomy. However, accurately diagnosing the depth of submucosal invasion via endoscopy is difficult. We developed a tool to diagnose the depth of submucosal invasion in early colorectal cancer using artificial intelligence. We reviewed data from 196 patients who had undergone a preoperative colonoscopy at the Osaka University Hospital and Osaka International Cancer Institute between 2011 and 2018 and were diagnosed pathologically as having shallow submucosal invasion or deep submucosal invasion colorectal cancer. A convolutional neural network for predicting invasion depth was constructed using 706 images from 91 patients between 2011 and 2015 as the training dataset. The diagnostic accuracy of the constructed convolutional neural network was evaluated using 394 images from 49 patients between 2016 and 2017 as the validation dataset. We also prospectively tested the tool from 56 patients in 2018 with suspected early-stage colorectal cancer. The sensitivity, specificity, accuracy, and area under the curve of the convolutional neural network for diagnosing deep submucosal invasion colorectal cancer were 87.2% (258/296), 35.7% (35/98), 74.4% (293/394), and 0.758, respectively. The positive predictive value was 84.4% (356/422) and the sensitivity was 75.7% (356/470) in the test set. The diagnostic accuracy of the constructed convolutional neural network seemed to be as high as that of a skilled endoscopist. Thus, endoscopic image recognition by deep learning may be able to predict the submucosal invasion depth in early-stage colorectal cancer in clinical practice.

Involvement of the Thalamus, Hippocampus, and Brainstem in Hypsarrhythmia of West Syndrome: Simultaneous Recordings of Electroencephalography and fMRI Study

BACKGROUND AND PURPOSE

West syndrome is a developmental and epileptic encephalopathy characterized by epileptic spasms, neurodevelopmental regression, and a specific EEG pattern called hypsarrhythmia. Our aim was to investigate the brain activities related to hypsarrhythmia at onset and focal epileptiform discharges in the remote period in children with West syndrome using simultaneous electroencephalography and fMRI recordings.

MATERIALS AND METHODS

Fourteen children with West syndrome underwent simultaneous electroencephalography and fMRI at the onset of West syndrome. Statistically significant blood oxygen level-dependent responses related to hypsarrhythmia were analyzed using an event-related design of 4 hemodynamic response functions with peaks at 3, 5, 7, and 9 seconds after the onset of each event. Six of 14 children had focal epileptiform discharges after treatment and underwent simultaneous electroencephalography and fMRI from 12 to 25 months of age.

RESULTS

At onset, positive blood oxygen level-dependent responses were seen in the brainstem (14/14 patients), thalami (13/14), basal ganglia (13/14), and hippocampi (13/14), in addition to multiple cerebral cortices. Group analysis using hemodynamic response functions with peaks at 3, 5, and 7 seconds showed positive blood oxygen level-dependent responses in the brainstem, thalamus, and hippocampus, while positive blood oxygen level-dependent responses in multiple cerebral cortices were seen using hemodynamic response functions with peaks at 5 and 7 seconds. In the remote period, 3 of 6 children had focal epileptiform discharge-related positive blood oxygen level-dependent responses in the thalamus, hippocampus, and brainstem.

CONCLUSIONS

Positive blood oxygen level-dependent responses with hypsarrhythmia appeared in the brainstem, thalamus, and hippocampus on earlier hemodynamic response functions than the cerebral cortices, suggesting the propagation of epileptogenic activities from the deep brain structures to the neocortices. Activation of the hippocampus, thalamus, and brainstem was still seen in half of the patients with focal epileptiform discharges after adrenocorticotropic hormone therapy.

Impact of the COVID-19 pandemic on colorectal cancer surgery in Japan: Clinical Study Group of Osaka University-A multicenter retrospective study

Aim

Due to the overwhelming spread of SARS-CoV-2 and its disruption of the healthcare system, delays and reduced numbers were reported for colorectal cancer screening, colonoscopies, and surgery during the COVID-19 pandemic. This multicenter retrospective study investigated the still poorly understood impact of the COVID-19 pandemic on colorectal cancer treatment in Japan.

Methods

This study was organized by the Clinical Study Group of Osaka University, which comprised 32 major institutions in Osaka. We retrospectively analyzed the number of surgeries and colonoscopies performed and the characteristics of patients who underwent surgery for colorectal cancer between March 2019 and February 2021. We compared data collected before and during the COVID-19 pandemic. We also assessed the methods used for detecting colorectal cancer, including fecal occult blood test, abdominal symptoms, and anemia.

Results

The COVID-19 pandemic caused reductions in the annual numbers of surgeries (3569 vs 3198) and colonoscopies (67 622 vs 58 183) performed in the 2020 fiscal year, compared to the 2019 fiscal year. During the COVID-19 pandemic, a significantly lower proportion of patients were treated for clinical stages ≤I (24.2% vs 26.9%; P = .011), compared to the proportion treated before the pandemic. Fecal occult blood tests for detecting colorectal cancer were used significantly less frequently during the COVID-19 pandemic (26.2% vs 29.6%; P = .002). These trends were more significant in larger institutions.

Conclusion

The COVID-19 pandemic reduced the number of colonoscopies and surgeries performed for colorectal cancer and hindered the detection of asymptomatic early-stage cancers, and its impact varied by hospital size.

Search for Subsolar-Mass Binaries in the First Half of Advanced LIGO's and Advanced Virgo's Third Observing Run

We report on a search for compact binary coalescences where at least one binary component has a mass between 0.2  M_{⊙} and 1.0  M_{⊙} in Advanced LIGO and Advanced Virgo data collected between 1 April 2019 1500 UTC and 1 October 2019 1500 UTC. We extend our previous analyses in two main ways: we include data from the Virgo detector and we allow for more unequal mass systems, with mass ratio q≥0.1. We do not report any gravitational-wave candidates. The most significant trigger has a false alarm rate of 0.14  yr^{-1}. This implies an upper limit on the merger rate of subsolar binaries in the range [220-24200]  Gpc^{-3} yr^{-1}, depending on the chirp mass of the binary. We use this upper limit to derive astrophysical constraints on two phenomenological models that could produce subsolar-mass compact objects. One is an isotropic distribution of equal-mass primordial black holes. Using this model, we find that the fraction of dark matter in primordial black holes in the mass range 0.2  M_{⊙}<m_{PBH}<1.0  M_{⊙} is f_{PBH}≡Ω_{PBH}/Ω_{DM}≲6%. This improves existing constraints on primordial black hole abundance by a factor of ∼3. The other is a dissipative dark matter model, in which fermionic dark matter can collapse and form black holes. The upper limit on the fraction of dark matter black holes depends on the minimum mass of the black holes that can be formed: the most constraining result is obtained at M_{min}=1  M_{⊙}, where f_{DBH}≡Ω_{DBH}/Ω_{DM}≲0.003%. These are the first constraints placed on dissipative dark models by subsolar-mass analyses.

PLXND1/SEMA3E Promotes Epithelial-Mesenchymal Transition Partly via the PI3K/AKT-Signaling Pathway and Induces Heterogenity in Colorectal Cancer

Colorectal cancer (CRC) is a major cause of cancer-related deaths. Metastasis is enhanced through epithelial-mesenchymal transition (EMT), a process primarily induced by the transforming growth factor beta (TGF-β)-mediated canonical Smad pathway. This study focused on plexin D1 (PLXND1), a chemoreceptor for the ligand SEMA3E to mechanosensory, showing that PLXND1 induces EMT via activation of the PI3K/AKT pathway in CRC cells. The findings showed that PLXND1-knockdown decreases cell migration and invasion significantly, and that the binding of p61-SEMA3E to the PLXND1 enhances the invasiveness and migration through EMT. Furin inhibitor suppresses EMT, decreasing cell migration and invasion. Furin cleaves full-length SEMA3E and converts it to p61-SEMA3E, suggesting that furin inhibitors block PLXND1 and p61-SEMA3E binding. Furin is a potential therapeutic target for the purpose of suppressing EMT by inhibiting the binding of p61-SEMA3E to PLXND1. In vivo experiments have shown that PLXND1-knockdown suppresses EMT. Mesenchymal cells labeled with ZEB1 showed heterogeneity depending on PLXND1 expression status. The high-expression group of PLXND1 in 182 CRC samples was significantly associated with poor overall survival compared with the low-expression group (P = 0.0352, median follow-up period of 60.7 months) using quantitative real-time polymerase chain reaction analysis. Further research is needed to determine whether cell fractions with a different expression of PLXND1 have different functions.

Utilization of phosphonic acid compounds by marine bacteria of the genera Phaeobacter, Ruegeria, and Thalassospira (α-Proteobacteria)

Phosphonic acid (phosphonate) that possesses a carbon (C)-P bond is a chemically stable form of organic phosphorus (P). Various phosphonic acids are widely distributed in oceanic waters; in particular, methylphosphonic acid (namely methylphosphonate) is believed to be responsible for global methane production. To discuss the microbial degradation of phosphonic acids, we investigated the utilization of phosphonic acid compounds by cultures of marine bacteria, Phaeobacter sp., Ruegeria sp. (Rhodobacterales), and Thalassospira sp. (Rhodospirillales). These bacterial cultures were able to grow on methylphosphonic acid as well as on the tested alkyl-, carboxy-, aminoalkyl-, and hydroxyalkyl-phosphonic acid compounds. Cell yields and growth rates of Ruegeria and Thalassospira cultures grown on methyl-, ethyl-, propyl-, and butyl-phosphonic acid compounds tended to decrease with increasing alkyl chain length. In contrast, Phaeobacter sp. grew well on such alkyl phosphonic acids. Our results suggest that these marine bacteria, which exhibit varied utilization, are involved in microbial degradation of various phosphonic acid compounds.

The Geriatric Nutritional Risk Index as a Prognosis Predictor in Patients With Rectal Cancer Receiving Neoadjuvant Chemotherapy

BACKGROUND/AIM

There are few reports on the clinical significance of the geriatric nutritional risk index (GNRI) in patients with locally advanced rectal cancer who undergo preoperative chemotherapy (NAC, neoadjuvant chemotherapy) followed by radical resection; this study examined the relationship between preoperative GNRI, postoperative complications, and prognosis in these patients.

PATIENTS AND METHODS

Fifty-seven patients with rectal cancer who underwent radical resection after NAC at Osaka University Hospital between November 2011 and May 2018 were included. The GNRI was calculated as follows: GNRI= [1.489×serum albumin level (g/l)]+[41.7×present/ideal body weight (kg)]. Patients were classified into high (GNRI ≥96.74; n=36) and low GNRI (GNRI <96.74; n=21) groups, based on the results of the receiver operating characteristic curve analysis.

RESULTS

The Kaplan-Meier analysis showed that the low GNRI group had a significantly poorer cancer-specific survival (CSS) and a poorer overall survival tendency than the high GNRI group. In the univariate analysis, venous invasion, lymphatic vessel invasion, and low GNRI were significantly correlated with CSS; depth of tumor invasion, lymph node metastasis, and lymphatic vessel invasion were significantly correlated with disease-free survival (DFS). In the multivariate analysis, there were no significantly poor prognostic factors for CSS and DFS.

CONCLUSION

Preoperative GNRI may be a useful predictor for recurrence and poor prognosis in elderly patients with rectal cancer who undergo radical resection after NAC. Further studies and accumulation of cases should investigate the relationship between preoperative GNRI and prognosis after NAC in elderly patients.

Postoperative pain management after concomitant sacrectomy for locally recurrent rectal cancer

PURPOSE

To assess pain management in patients post-sacrectomy, focusing on opioid use, and to identify the factors associated with postoperative pain.

METHODS

Patients who underwent resection of locally recurrent rectal cancer (LRRC) with concomitant sacrectomy at one of two hospitals between 2007 and 2020 were reviewed retrospectively. We examined the use of opioids preoperatively and postoperatively. Patients were classified into high and low sacrectomy groups based on the sacral bone resection level passing through the S3 vertebra.

RESULTS

Sixty-four patients were enrolled. Opioid use was significantly higher in the high sacrectomy group than in the low sacrectomy group at all times assessed: on postoperative days 7, 14, 30, 90, 180, and 365. Opioid use 3 months after locally recurrent rectal cancer surgery was significantly higher in patients with local re-recurrence of the tumor than in those without re-recurrence (p < 0.05), and the median morphine-equivalent opioid use 3 months postoperatively was significantly higher in the high sacrectomy group (30 vs. 0 mg/day; p < 0.05).

CONCLUSIONS

Opioid use after concomitant sacrectomy for LRRC was higher in the high sacrectomy group. Prolonged postoperative pain or increasing pain was associated with local recurrence.

AB0157 EFFICACY AND SAFETY OF FILGOTINIB IN ACTIVE RHEUMATOID ARTHRITIS PATIENTS WITH INADEQUATE RESPONSE TO METHOTREXATE: COMPARATIVE STUDY WITH FILGOTINIB AND TOCILIZUMAB EXAMINED BY CLINICAL INDEX AS WELL AS MUSCULOSKELETAL ULTRASOUND ASSESSMENT (TRANSFORM STUDY): STUDY PROTOCOL

Background

The administration of Janus kinase (JAK) inhibitors as well as biological disease-modifying anti-rheumatic drugs has dramatically improved even the clinical outcomes in rheumatoid arthritis (RA) patients with inadequate response to methotrexate (MTX). The dysregulation of JAK- signal transducer and activator of transcription (STAT) pathways via overproduction of cytokines, such as interleukin-6 (IL-6) is involved in the pathogenesis of RA (1). Filgotinib, a preferential JAK1 inhibitor, is effective in suppressing disease activity and preventing the progression of joint destruction due to inhibition of the JAK-STAT pathway. IL-6 inhibitors such as tocilizumab also inhibit the JAK-STAT pathways due to inhibition of IL-6 signaling. Thus, it should be desirable to investigate whether the effectiveness of filgotinib monotherapy is non-inferior to those of tocilizumab monotherapy in RA patients with inadequate response to MTX. In addition, it is important to accurately evaluate disease activity at the joint level by using musculoskeletal ultrasound (MSUS) and clinical disease activity indices, including subjective parameters (2).

Objectives

This study’s principal objective is to evaluate the effects of filgotinib monotherapy is non-inferior to those of tocilizumab monotherapy in RA patients with inadequate response to MTX. In addition, we will evaluate changes in patients’ parameters, including clinical disease activity indices, MSUS scores, serum biomarkers, patient-reported outcome (PRO), and modified total Sharp score (mTSS) after the administration of filgotinib or tocilizumab. Herein, we describe the study protocol for this study.

Methods

This study is an interventional, multicenter, randomized, open-label, parallel-group and non-inferiority clinical trial with a 52-week follow-up. In total, 400 RA patients with at least moderate disease activity during treatment with MTX will be included. Patients will be randomized in a 1:1 ratio to administration of filgotinib 200mg/day monotherapy or subcutaneous tocilizumab 162mg/biweekly monotherapy switched from MTX (Figure 1). We will evaluate disease activity by measuring clinical disease activity indices and by using MSUS. The primary endpoint is the proportion of patients who achieve an American College of Rheumatology 50 response at week 12. Important secondary endpoints are the changes from the baseline of the MSUS scores, PRO, and mTSS. We will also comprehensively analyze the serum levels of multiple biomarkers such as cytokines and chemokines.

Figure 1.

Results

Although the study results cannot be shown because the research entry is in progress, they are expected to show the non-inferiority of filgotinib monotherapy to tocilizumab monotherapy in RA patients with inadequate response to MTX.

Conclusion

The strength of this study is its prospective evaluation of therapeutic efficacy using not only clinical disease activity indices but also MSUS, which accurately and objectively evaluate disease activity at the joint level among patients drawn from multiple centers with a standardized evaluation by MSUS. In addition, we will evaluate the effectiveness of both drugs by integrating multilateral assessments, i.e., clinical disease activity indices, MSUS findings, and serum biomarkers.

References

[1]Gadina M, Le MT, Schwartz DM, Silvennoinen O, Nakayamada S, Yamaoka K, et al. Janus kinases to jakinibs: from basic insights to clinical practice. Rheumatology (Oxford). 2019;58(Suppl 1):i4-i16.

[2]Colebatch AN, Edwards CJ, Ostergaard M, van der Heijde D, Balint PV, D’Agostino MA, et al. EULAR recommendations for the use of imaging of the joints in the clinical management of rheumatoid arthritis. Ann Rheum Dis. 2013;72(6):804-14.

Disclosure of Interests

Toshimasa Shimizu: None declared, Shin-ya Kawashiri: None declared, Shimpei Morimoto: None declared, Yurika Kawazoe: None declared, Shohei Kuroda: None declared, Rina Kawasaki: None declared, Yasuko Ito: None declared, Shuntaro Sato: None declared, Hiroshi Yamamoto: None declared, Atsushi Kawakami Grant/research support from: Gilead Sciences, Inc.

Fecal Stream Diversion Changes Intestinal Environment, Modulates Mucosal Barrier, and Attenuates Inflammatory Cells in Crohn's Disease

BACKGROUND

The intestinal environment plays important roles in mucosal barrier homeostasis and intestinal inflammation, as clarified in studies using experimental animals but not in humans.

AIMS

We investigated whether environmental changes in the fecal stream cause phenotypic changes in the human mucosal barrier.

METHODS

We obtained human ileal samples after fecal stream diversions in patients with rectal cancer or Crohn's disease. We investigated the bacterial load and diversity in the human defunctioned ileum, defined as the anal side of the ileum relative to the ileostomy. We also examined the epithelium and lamina propria cell phenotypes in the defunctioned ileum.

RESULTS

After fecal stream diversion, bacterial loads decreased significantly in the defunctioned ileum. Based on the Chao1, Shannon, and observed species indices, the diversity of mucosa-associated microbiota was lower in the defunctioned ileum than in the functional ileum. Moreover, the healthy defunctioned ileum showed reductions in villous height, goblet cell numbers, and Ki-67⁺ cell numbers. Additionally, interferon-γ⁺, interleukin-17⁺, and immunoglobulin A⁺ cell abundance in the lamina propria decreased. After the intestinal environment was restored with an ileostomy closure, the impaired ileal homeostasis recovered. The defunctioned ileum samples from patients with Crohn's disease also showed reductions in interferon-γ⁺ and interleukin-17⁺ cell numbers.

CONCLUSIONS

Fecal stream diversion reduced the abundance and diversity of intestinal bacteria. It also altered the intestinal mucosal barrier, similar to the alterations observed in germ-free animals. In patients with Crohn's disease, Th1 and Th17 cell numbers were attenuated, which suggests that the host-microbiome interaction is important in disease pathogenesis.

Low G9a expression is a tumor progression factor of colorectal cancer via IL-8 promotion

The histone methyltransferase G9a is expressed in various types of cancer cells, including colorectal cancer (CRC) cells. Interleukin (IL)-8, also known as C-X-C motif chemokine ligand 8 (CXCL8), is a chemokine that plays a pleiotropic function in the regulation of inflammatory responses and cancer development. Here, we examined the relationship between G9a and IL-8 and the clinical relevance of this association. We immunohistochemically analyzed 235 resected CRC samples to correlate clinical features. Samples with high G9a expression had better overall survival and relapse-free survival than those with low G9a expression. Univariate and multivariate analyses demonstrated that low G9a expression remained a significant independent prognostic factor for increased disease recurrence and decreased survival (P<0.05). G9a was expressed at high levels in commercially available CRC cell lines HCT116 and HT29. Knockdown of G9a by siRNA, shRNA, or the G9a-specific inhibitor BIX01294 upregulated IL-8 expression. The number of spheroids was significantly increased in HCT116 cells with stably suppressed G9a expression, and the number of spheroids was significantly decreased in HCT116 cells with stably suppressed IL-8 expression. Thus, the suppression of IL-8 by G9a may result in a better prognosis in CRC cases with high G9a expression. Furthermore, G9a may suppress cancer stemness and increase chemosensitivity by controlling IL-8. Therefore, G9a is a potential novel marker for predicting CRC prognosis, and therapeutic targeting of G9a in CRC should be contraversial.

Micrometastasis in lymph nodes of colorectal cancer

Colorectal cancer (CRC) is one of the most common cancers worldwide. Postoperative adjuvant chemotherapy is recommended for node‐positive stage III patients. A systematic meta‐analysis reported that the presence of micrometastases in regional lymph nodes (LNs) was associated with poor survival in patients with node‐negative CRC. Because most data employed in the meta‐analysis were based on retrospective studies, we conducted a prospective clinical trial and concluded that stage II is a transitional zone between stage I and stage III, where CRC tumors continuously increase the micrometastasis volume in LNs and proportionally raise the risk for tumor recurrence. The one‐step nucleic acid amplification (OSNA) assay is a simple and rapid technique to detect CK19 mRNA using the reverse‐transcription loop‐mediated isothermal amplification (RT‐LAMP) method. Using the OSNA assay, we and colleagues reported that the upstaging rates of pStages I, IIA, IIB, and IIC were 2.0%, 17.7%, 12.5%, and 25%, respectively, in 124 node‐negative patients. Survival analysis indicated that OSNA positive stage II CRC patients had a shorter 3‐y disease‐free survival rate than OSNA negative stage II CRC patients. In 2017, AJCC TNM staging (the 8th version) revised the definition of LN metastasis in colon cancer and it is stated that micrometastasis should be considered as a standard LN metastasis. To our surprise, this revision was based on a meta‐analysis to which our previous study on micrometastasis largely contributed. The remaining questions to be addressed are how to find micrometastases efficiently and whether postadjuvant chemotherapy is effective to prevent disease recurrence and to contribute to longer survival.

Design and Synthesis of Tranylcypromine-Derived LSD1 Inhibitors with Improved hERG and Microsomal Stability Profiles

Lysine-specific demethylase 1 (LSD1/KDM1A) is a promising therapeutic target for the treatment of cancers. Several derivatives of tranylcypromine (trans-2-phenylcyclopropylamine) have been developed as LSD1 inhibitors. One such derivative is S2157; however, this compound has a high hERG channel inhibitory activity and a low microsomal stability, making it unsuitable as a drug candidate. Here, using an in silico hERG inhibition prediction model, we designed, synthesized, and evaluated a novel series of S2157 derivatives characterized by modifications of the benzyloxy and piperazine groups. Among the synthesized derivatives, a compound possessing 2-fluoropyridine and 2,8-diaza-spiro[4.5]decane groups (compound 10) showed the most desirable activities, and its eutomer, S1427, was isolated by the optical resolution of 10. In addition to potent LSD1 inhibitory activity, S1427 exhibited desirable hERG channel inhibition and microsomal stability profiles.