Spatial and single-cell colocalisation analysis reveals MDK-mediated immunosuppressive environment with regulatory T cells in colorectal carcinogenesis

BACKGROUND

Cell-cell interaction factors that facilitate the progression of adenoma to sporadic colorectal cancer (CRC) remain unclear, thereby hindering patient survival.

METHODS

We performed spatial transcriptomics on five early CRC cases, which included adenoma and carcinoma, and one advanced CRC. To elucidate cell-cell interactions within the tumour microenvironment (TME), we investigated the colocalisation network at single-cell resolution using a deep generative model for colocalisation analysis, combined with a single-cell transcriptome, and assessed the clinical significance in CRC patients.

FINDINGS

CRC cells colocalised with regulatory T cells (Tregs) at the adenoma-carcinoma interface. At early-stage carcinogenesis, cell-cell interaction inference between colocalised adenoma and cancer epithelial cells and Tregs based on the spatial distribution of single cells highlighted midkine (MDK) as a prominent signalling molecule sent from tumour epithelial cells to Tregs. Interaction between MDK-high CRC cells and SPP1+ macrophages and stromal cells proved to be the mechanism underlying immunosuppression in the TME. Additionally, we identified syndecan4 (SDC4) as a receptor for MDK associated with Treg colocalisation. Finally, clinical analysis using CRC datasets indicated that increased MDK/SDC4 levels correlated with poor overall survival in CRC patients.

INTERPRETATION

MDK is involved in the immune tolerance shown by Tregs to tumour growth. MDK-mediated formation of the TME could be a potential target for early diagnosis and treatment of CRC.

FUNDING

Japan Society for the Promotion of Science (JSPS) Grant-in-Aid for Science Research; OITA Cancer Research Foundation; AMED under Grant Number; Japan Science and Technology Agency (JST); Takeda Science Foundation; The Princess Takamatsu Cancer Research Fund.

Field experiment of a telesurgery system using a surgical robot with haptic feedback

PURPOSE

To verify the usefulness of haptic feedback in telesurgery and improve the safety of telerobotic surgery.

METHODS

The surgeon's console was installed at two sites (Fukuoka and Beppu; 140 km apart), and the patient cart was installed in Fukuoka. During the experiment, the surgeon was blinded to the haptic feedback levels and asked to grasp the intestinal tract in an animal model. The surgeon then performed the tasks at each location.

RESULTS

No marked differences in task accuracy or average grasping force were observed between the surgeon locations. However, the average task completion time was significantly longer, and the system usability scale (SUS) was significantly lower rating for remote operations than for local ones. No marked differences in task accuracy or task completion time were observed between the haptic feedback levels. However, with haptic feedback, the organ was grasped with a significantly weaker force than that without it. Furthermore, with haptic feedback, experienced surgeons in robotic surgery tended to perform an equivalent task with weaker grasping forces than inexperienced surgeons.

CONCLUSION

The haptic feedback function is a tool that allows the surgeon to perform surgery with an appropriate grasping force, both on site and remotely. Improved safety is necessary in telesurgery; haptic feedback will thus be an essential technology in robotic telesurgery going forward.

Implementable assay for monitoring minimum residual disease after radical treatment for colorectal cancer

Considering the cost and invasiveness of monitoring postoperative minimal residual disease (MRD) of colorectal cancer (CRC) after adjuvant chemoradiotherapy (ACT), we developed a favorable approach based on methylated circulating tumor DNA to detect MRD after radical resection. Analyzing the public database, we identified the methylated promoter regions of the genes FGD5, GPC6, and MSC. Using digital polymerase chain reaction (dPCR), we termed the "amplicon of methylated sites using a specific enzyme" assay as "AMUSE." We examined 180 and 114 pre- and postoperative serial plasma samples from 28 recurrent and 19 recurrence-free pathological stage III CRC patients, respectively. The results showed 22 AMUSE-positive of 28 recurrent patients (sensitivity, 78.6%) and 17 AMUSE-negative of 19 recurrence-free patients (specificity, 89.5%). AMUSE predicted recurrence 208 days before conventional diagnosis using radiological imaging. Regarding ACT evaluation by the reactive response, 19 AMUSE-positive patients during their second or third blood samples showed a significantly poorer prognosis than the other patients (p = 9E-04). The AMUSE assay stratified four groups by the altered patterns of tumor burden postoperatively. Interestingly, only 34.8% of cases tested AMUSE-negative during ACT treatment, indicating eligibility for ACT. The AMUSE assay addresses the clinical need for accurate MRD monitoring with universal applicability, minimal invasiveness, and cost-effectiveness, thereby enabling the timely detection of recurrences. This assay can effectively evaluate the efficacy of ACT in patients with stage III CRC following curative resection. Our study strongly recommends reevaluating the clinical application of ACT using the AMUSE assay.

Tumor suppressive role of the epigenetic master regulator BRD3 in colorectal cancer

Bromodomain and extraterminal domain (BET) family proteins are epigenetic master regulators of gene expression via recognition of acetylated histones and recruitment of transcription factors and co-activators to chromatin. Hence, BET family proteins have emerged as promising therapeutic targets in cancer. In this study, we examined the functional role of bromodomain containing 3 (BRD3), a BET family protein, in colorectal cancer (CRC). In vitro and vivo analyses using BRD3-knockdown or BRD3-overexpressing CRC cells showed that BRD3 suppressed tumor growth and cell cycle G1/S transition and induced p21 expression. Clinical analysis of CRC datasets from our hospital or The Cancer Genome Atlas revealed that BET family genes, including BRD3, were overexpressed in tumor tissues. In immunohistochemical analyses, BRD3 was observed mainly in the nucleus of CRC cells. According to single-cell RNA sequencing in untreated CRC tissues, BRD3 was highly expressed in malignant epithelial cells, and cell cycle checkpoint-related pathways were enriched in the epithelial cells with high BRD3 expression. Spatial transcriptomic and single-cell RNA sequencing analyses of CRC tissues showed that BRD3 expression was positively associated with high p21 expression. Furthermore, overexpression of BRD3 combined with knockdown of, a driver gene in the BRD family, showed strong inhibition of CRC cells in vitro. In conclusion, we demonstrated a novel tumor suppressive role of BRD3 that inhibits tumor growth by cell cycle inhibition in part via induction of p21 expression. BRD3 activation might be a novel therapeutic approach for CRC.

Liquid biopsy for breast cancer and other solid tumors: a review of recent advances

Liquid biopsy using circulating tumor DNA (ctDNA) has been reported to be less invasive and effective for comprehensive genetic analysis of heterogeneous solid tumors, including decision-making for therapeutic strategies, predicting recurrence, and detecting genetic factors related to treatment resistance in various types of cancers. Breast cancer, colorectal cancer, and lung cancer are among the most prevalent malignancies worldwide, and clinical studies of liquid biopsy for these cancers are ongoing. Liquid biopsy has been used as a companion diagnostic tool in clinical settings, and research findings have accumulated, especially in cases of colorectal cancer after curative resection and non-small cell lung cancer (NSCLC) after curative chemoradiotherapy, in which ctDNA detection helps predict eligibility for adjuvant chemotherapy. Liquid biopsy using ctDNA shows promise across a wide range of cancer types, including breast cancer, and its clinical applications are expected to expand further through ongoing research. In this article, studies on liquid biopsy in breast cancer, colorectal cancer, and NSCLC are compared focusing on ctDNA.

What Are Risk Factors for Graft Loss in Patients Who Underwent Simultaneous Splenectomy During Living-donor Liver Transplantation?

BACKGROUND

The consensus that portal venous pressure modulation, including splenectomy (Spx), prevents portal hypertension-related complications after living-donor liver transplantation (LDLT) has been established. However, little evidence about the risk factors for graft loss after simultaneous Spx during LDLT is available. This study aimed to identify the independent predictors of graft loss after simultaneous Spx during LDLT.

METHODS

Data of 655 recipients who underwent LDLT between 1997 and 2021 were collected and separated into the simultaneous Spx group (n = 461) and no-Spx group (n = 194).

RESULTS

The simultaneous Spx group had significantly lower serum total bilirubin levels, drained ascites volumes, and prothrombin time-international normalized ratios on postoperative day 14 than the no-Spx group (P < 0.001 for each). Incidences of small-for-size graft syndrome (P < 0.001), acute cellular rejection (P = 0.002), and sepsis (P = 0.007) were significantly lower in the Spx group. Graft survival of the Spx group was significantly better than that of the no-Spx group (P < 0.001; hazard ratio [HR], 1.788; 95% confidence interval, 1.214-2.431). A multivariate analysis revealed that 3 variables, platelet count ≤4.0 × 104/mm3 (P = 0.029; HR, 2.873), donor age ≥60 y old (P = 0.013; HR, 6.693), and portal venous pressure at closure ≥20 mm Hg (P = 0.010; HR, 3.891), were independent predictors of graft loss within 6 mo after simultaneous Spx during LDLT.

CONCLUSIONS

Spx is a safe inflow modulation procedure with a positive impact on both postoperative complications and prognosis for most patients. However, patients with the 3 aforementioned independent factors could experience graft loss after LDLT.

Case report: A rare case of triple negative breast cancer with development of acute pancreatitis due to dexamethasone during adjuvant chemotherapy

Here, we present the case of a 42-year-old female who developed acute pancreatitis due to dexamethasone during adjuvant chemotherapy for early triple negative breast cancer (TNBC). The patient received partial mastectomy and sentinel lymph node biopsy for early TNBC (cT1N0M0, cStage I) of the left breast. Dose-dense doxorubicin plus cyclophosphamide (ddAC) was administered as the adjuvant-chemotherapy; however, epigastralgia appeared on the fifth day of the first administration. A blood test showed a remarkable increase of serum pancreatic enzyme levels and computed tomography (CT) showed the swelling of pancreas and surrounding effusion, and she was diagnosed with moderate acute pancreatitis. As she had no history of excessive alcohol consumption or complication of cholelithiasis, dyslipidemia, or pancreatic neoplasm, drug-induced pancreatitis was suspected. Dexamethasone, which was administered as an antiemetic, was the suspected drug based on the drug administration history and previous report, and dexamethasone was discontinued from the second administration of ddAC. There was subsequently no recurrence of pancreatitis with no increase in serum pancreatic enzyme levels, and it was possible to complete adjuvant-chemotherapy. Alcohol, gallstones, dyslipidemia, and drugs have been reported as causes of pancreatitis; however, steroid-induced acute pancreatitis is extremely rare. We present the first case of acute pancreatitis induced by dexamethasone as the antiemetic.

Third Report of the Japan Diabetes Society/Japanese Cancer Association Joint Committee on Diabetes and Cancer: Summary of the results of a questionnaire survey of oncologists and diabetologists-Secondary publication

The Japan Diabetes Society and the Japan Cancer Association launched a joint committee and published their "First Joint Committee Report on Diabetes and Cancer" in 2013, compiling recommendations for physicians and health-care providers as well as for the general population. In 2016, the "Second Joint Committee Report on Diabetes and Cancer" summarized the current evidence on glycemic control and cancer risk in patients with diabetes. The current "Third Joint Committee Report on Diabetes and Cancer", for which the joint committee also enlisted the assistance of the Japanese Society of Clinical Oncology and the Japanese Society of Medical Oncology, reports on the results from the questionnaire survey, "Diabetes Management in Patients Receiving Cancer Therapy," which targeted oncologists responsible for cancer management and diabetologists in charge of glycemic control in cancer patients. The results of the current survey indicated that there is a general consensus among oncologists and diabetologists with regard to the need for guidelines on glycemic control goals, the relevance of glycemic control, and glycemic control during cancer therapy in cancer patients.

A rare case of liver regenerative and non-neoplastic lesion resembling a well-differentiated hepatocellular carcinoma

BACKGROUND

Nodular regenerative hyperplasia (NRH) is a rare disease that presents pathologically as diffuse hepatic nodules without fibrous septa. It is believed to be caused by vasculopathy against a background of various systemic diseases, such as hematologic, autoimmune, and drug-induced diseases, with various symptoms. In spite of the recent imaging advances, various atypical cases of nodular lesions are observed in daily clinical practice. Cases that do not completely meet these criteria are referred to as -like or -similar lesions in clinical situations, making it difficult to understand their pathogenesis. We present a case in which two hepatic nodular lesions were noted and difficult to differentiate from malignancy preoperatively. The lesions were laparoscopically resected and a pathological diagnosis with non-neoplastic liver regenerative nodules resembling NRH was made.

CASE PRESENTATION

A 49-year-old man with no alcohol or drug intake and no past medical history was identified as having liver tumors on screening examination without any symptoms. Contrast-enhanced computed tomography (CT) showed two hepatic tumors; approximately 2-cm tumors at S7 and S8. Gadolinium-ethoxybenzyl-diethylenetriamine-pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) revealed fat inclusions in their contents. Ethoxybenzyl (EOB) uptake was also observed during the hepatobiliary phase. Based on preoperative examinations, we suspected well-differentiated hepatocellular carcinoma (HCC) and performed laparoscopic S7/8 partial resection for these lesions. Macroscopically, the resected specimens showed a non-cirrhotic yellowish-cut surface containing brownish, ill-defined lesions with irregular borders. Microscopically, these lesions showed zonal necrosis, congestion, and aggregation of hemosiderin-laden macrophages around the central vein. In these areas, the fatty deposition of hepatocytes was lower than that in the surrounding background hepatocytes. Histopathologically, neither neoplastic nor hyperplastic lesions were observed, and he was diagnosed as regenerative hepatic change with centrilobular necrosis.

CONCLUSIONS

Considering the pathological results, these lesions were thought to be a type of NRH-like lesion with possible hepatic vessel disorder. However, the lesion's cause and classification was difficult to determine. The accumulation of these regenerative changes accompanying fatty liver is needed to clarify the mechanism and its clinical significance.

Third Report of the Japan Diabetes Society (JDS)/Japanese Cancer Association (JCA) Joint Committee on diabetes and cancer: summary of the results of a questionnaire survey of oncologists and diabetologists-secondary publication

The Japan Diabetes Society (JDS) and the Japan Cancer Association (JCA) launched a joint committee and published their "First Joint Committee Report on Diabetes and Cancer" in 2013, compiling recommendations for physicians and healthcare providers as well as for the general population. In 2016, the "Second Joint Committee Report on Diabetes and Cancer" summarized the current evidence on glycemic control and cancer risk in patients with diabetes. The current "Third Joint Committee Report on Diabetes and Cancer", for which the joint committee also enlisted the assistance of the Japanese Society of Clinical Oncology (JSCO) and the Japanese Society of Medical Oncology (JSMO), reports on the results from the questionnaire survey, "Diabetes Management in Patients Receiving Cancer Therapy," which targeted oncologists responsible for cancer management and diabetologists in charge of glycemic control in cancer patients. The results of the current survey demonstrated that there is a general consensus among oncologists and diabetologists with regard to the need for guidelines on glycemic control goals, the relevance of glycemic control, and glycemic control during cancer therapy in cancer patients.

Real-time telementoring with 3D drawing annotation in robotic surgery

BACKGROUND

In telementoring, differences in teaching methods affect local surgeons' comprehension. Because the object to be operated on is a three-dimensional (3D) structure, voice or 2D annotation may not be sufficient to convey the instructor's intention. In this study, we examined the usefulness of telementoring using 3D drawing annotations in robotic surgery.

METHODS

Kyushu University and Beppu Hospital are located 140 km apart, and the study was conducted using a Saroa™ surgical robot by RIVERFIELD Inc. using a commercial guarantee network on optical fiber. Twenty medical students performed vertical mattress suturing using a swine intestinal tract under surgical guidance at the Center for Advanced Medical Innovation Kyushu University. Surgical guidance was provided by Beppu Hospital using voice, 2D, and 3D drawing annotations. All robot operations were performed using 3D images, and only the annotations were independently switched between voice and 2D and 3D images. The operation time, needle movement, and performance were also evaluated.

RESULTS

The 3D annotation group tended to have a shorter working time than the control group (25.6 ± 63.2 vs. - 36.7 ± 65.4 min, P = 0.06). The 3D annotation group had fewer retries than the control group (1.3 ± 1.7 vs. - 1.1 ± 0.7, P = 0.006), and there was a tendency for fewer needle drops (0.4 ± 0.7 vs. - 0.5 ± 0.9, P = 0.06). The 3D annotation group scored significantly higher than the control group on the Global Evaluate Assessment of Robot Skills (16.8 ± 2.0 vs. 22.8 ± 2.4, P = 0.04). The 3D annotation group also scored higher than the voice (13.4 ± 1.2) and 2D annotation (16.2 ± 1.8) groups (3D vs. voice: P = 0.03, 3D vs. 2D: P = 0.03).

CONCLUSION

Telementoring using 3D drawing annotation was shown to provide good comprehension and a smooth operation for local surgeons.

Transducin Beta-Like 2 is a Potential Driver Gene that Adapts to Endoplasmic Reticulum Stress to Promote Tumor Growth of Lung Adenocarcinoma

BACKGROUND

Endoplasmic reticulum (ER) stress has a close relation with cancer progression. Blocking the adaptive pathway of ER stress could be an anticancer strategy. Here, we identified an ER stress-related gene, Transducin beta-like 2 (TBL2), an ER-localized type I transmembrane protein, on increased chromosome 7q as a candidate driver gene of lung adenocarcinoma (LUAD).

METHODS

The association between TBL2 mRNA expression and prognostic outcomes and clinicopathological factors was analyzed using The Cancer Genome Atlas (TCGA) datasets of LUAD and lung squamous cell carcinoma (LUSC). Localization of TBL2 in tumor tissues was observed by immunohistochemical staining. Gene set enrichment analysis (GSEA) was conducted using TCGA dataset. In vitro cell proliferation assays were performed using TBL2 knockdown LUAD cells, LUSC cells, and LUAD cells overexpressing TBL2. Apoptosis and ATF4 expression (ER stress marker) were evaluated by western blotting.

RESULTS

TBL2 was overexpressed in LUAD and LUSC cells. Multivariate analysis indicated high TBL2 mRNA expression was an independent poor prognostic factor of LUAD. GSEA revealed high TBL2 expression was positively correlated to the ER stress response in LUAD. TBL2 knockdown attenuated LUAD cell proliferation under ER stress. TBL2 inhibited apoptosis in LUAD cells under ER stress. TBL2 knockdown reduced ATF4 expression under ER stress.

CONCLUSIONS

TBL2 may be a novel driver gene that facilitates cell proliferation, possibly by upregulating ATF4 expression followed by adaptation to ER stress, and it is a poor prognostic biomarker of LUAD.

Subclonal accumulation of immune escape mechanisms in microsatellite instability-high colorectal cancers

BACKGROUND

Intratumor heterogeneity (ITH) in microsatellite instability-high (MSI-H) colorectal cancer (CRC) has been poorly studied. We aimed to clarify how the ITH of MSI-H CRCs is generated in cancer evolution and how immune selective pressure affects ITH.

METHODS

We reanalyzed public whole-exome sequencing data on 246 MSI-H CRCs. In addition, we performed a multi-region analysis from 6 MSI-H CRCs. To verify the process of subclonal immune escape accumulation, a novel computational model of cancer evolution under immune pressure was developed.

RESULTS

Our analysis presented the enrichment of functional genomic alterations in antigen-presentation machinery (APM). Associative analysis of neoantigens indicated the generation of immune escape mechanisms via HLA alterations. Multiregion analysis revealed the clonal acquisition of driver mutations and subclonal accumulation of APM defects in MSI-H CRCs. Examination of variant allele frequencies demonstrated that subclonal mutations tend to be subjected to selective sweep. Computational simulations of tumour progression with the interaction of immune cells successfully verified the subclonal accumulation of immune escape mutations and suggested the efficacy of early initiation of an immune checkpoint inhibitor (ICI) -based treatment.

CONCLUSIONS

Our results demonstrate the heterogeneous acquisition of immune escape mechanisms in MSI-H CRCs by Darwinian selection, providing novel insights into ICI-based treatment strategies.

Successful multidisciplinary treatment with complete response to atezolizumab plus bevacizumab in a 90-year-old patient with hepatocellular carcinoma recurrence

Atezolizumab plus bevacizumab is the first-line regimen in Japan for hepatocellular carcinoma following the results of the IMbrave 150 trial. However, the safety and efficiency of atezolizumab plus bevacizumab in older patients, especially in the oldest-old patients aged over 80 years, have not been thoroughly studied and is still controversial. Eighteen months ago, a 90-year-old woman underwent a laparoscopic hepatectomy (S6) for her primary hepatocellular carcinoma (S6, 2 cm). Nine months after the first surgery, she received transcatheter arterial chemoembolization treatment for solitary hepatocellular carcinoma recurrence (S8, 2 cm). The subsequent recurrence (S3, 1 cm; S5, 2 cm; S8, 1 cm) was uncovered by radiological assessment 1 year after transcatheter arterial chemoembolization treatment. We then initiated chemotherapy treatment with lenvatinib at 8 mg daily. Despite reducing the lenvatinib dosage, the adverse event of severe fatigue and asitia did not resolve; therefore, the regimen of atezolizumab + bevacizumab combination therapy was changed to be started. After the first 2 months, tumor regression was observed on computed tomography; the patient tolerated the atezolizumab + bevacizumab combination regimen over 8 months for 10 cycles without any adverse effects. She finally showed a complete response; no recurrence developed 1 year after the complete response. Therefore, older adult patients may benefit highly from atezolizumab plus bevacizumab with appropriate patient selection.

Fibrolamellar hepatocellular carcinoma: a case report and gene analysis

BACKGROUND

Fibrolamellar hepatocellular carcinoma (HCC) (FL-HCC) is rare in Japan. FL-HCC develops in young patients with no history of cirrhosis and tends to manifest lymphatic metastasis with clinical features similar to those of HCC. We present a case of FL-HCC in a young male patient.

CASE PRESENTATION

A 14-year-old male patient underwent abdominal computed tomography (CT) to diagnose appendicitis, wherein a hepatic tumor was detected. Dynamic enhanced CT revealed a 35-mm solid tumor, which contrasted at the early phase of dynamic enhanced study of the right hepatic segments, with occlusion of the right portal vein. We performed right hepatectomy for these lesions. The patient experienced a single lymphatic recurrence on the hepatoduodenal ligament 12 months after the initial surgery. We performed lymphadenectomy for the recurrent tumor. We performed RNA sequencing (RNA-seq) and targeted DNA sequencing of the resected specimens (primary tumor, lymphatic metastasis, and normal liver). RNA-seq detected DNAJB1-PRKACA in both primary and metastatic lesions as previously reported. Furthermore, The Cancer Genome Atlas (TCGA) database was used to compare other gene expressions in this case with those of previously reported cases of FL-HCC and HCC in young patients. Principal component analysis of differentially expressed genes in the top 10% revealed that the gene expression in our case was similar to that of previous FL-HCC cases but was a different cluster from that in HCC cases in young patients. Mutational analysis did not detect any somatic mutations associated with carcinogenesis, including previously reported mutations (Kastenhuber et al. in Proc Natl Acad Sci USA 114: 13076-84, 2017).

CONCLUSION

We encountered a case of FL-HCC, a rare hepatic tumor in an adolescent patient, and evaluated the genetic background. Our findings could contribute to the elucidation of the mechanisms underlying carcinogenesis and progression in patients with FL-HCC and thereby contribute to the development of new therapeutic strategies in the future that may improve patient prognosis.

Hot spring bathing practices have a positive effect on mental health in Japan

Hot springs have long been used for medical purposes throughout the world. Recently, the positive effects of hot spa-bathing on circulatory diseases have been reported, while there are few reports on the mental effects of hot spa-bathing. Therefore, the purpose of this study was to clarify the relationship between hot spa-bathing habits and mental health throughout Japan. We conducted a nationwide online survey, including questions on bathing behavior, subjective satisfaction, lifestyle, and illness. The results showed a significant positive correlation between hot spa-bathing habits and multiple subjective satisfaction levels regarding mental health effects. The factor analysis results indicated that hot spa-bathing habits tended to be associated with good mental health, high health consciousness, and disease. Our study revealed that subjective satisfaction was higher among individuals with hot spa-bathing habits, suggesting that the hot spring spa-bathing habit may have a positive influence on mental health.

The comprehensive review of gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS) from diagnosis and treatment

Gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS) was first proposed by Wothley et al. in 2012 as a rare familial gastric cancer syndrome associated with an autosomal dominant form of inheritance. GAPPS is characterized by gastric basal gland polyposis from the hilum to the body of the stomach. Li et al. in 2016 showed that the cause of the disease is a point mutation in the promotor 1B region of the APC gene, and genetic testing was used to confirm the diagnosis. If the patient has already developed gastric cancer, treatment should be based on the usual treatment for gastric cancer. If no distant metastases exist, a good prognosis can be expected by performing a total gastrectomy. On the other hand, patients with distant metastasis have a poor prognosis. In the case of dysplasia, prophylactic total gastrectomy is recommended, but because it is highly invasive and postoperative postgastrectomy syndrome must be considered, the decision should be made with careful consideration of the patient's background. Therefore, there are no guidelines for screening for GAPPS, the timing of prophylactic total gastrectomy, or methods of endoscopic surveillance. Because GAPPS is a rare disease, its natural history is still unclear. Further case series are needed to elucidate the molecular biology and clinicopathological features of GAPPS and to establish clinical management, including diagnosis, treatment, and surveillance. In this review, we provide an overview of GAPPS, its clinical management, and its problems, which will be useful for the treatment of GAPPS.

Telesurgery and telesurgical support using a double-surgeon cockpit system allowing manipulation from two locations

BACKGROUND

Although several studies on telesurgery have been reported globally, a clinically applicable technique has not yet been developed. As part of a telesurgical study series conducted by the Japan Surgical Society, this study describes the first application of a double-surgeon cockpit system to telesurgery.

METHODS

Surgeon cockpits were installed at a local site and a remote site 140 km away. Three healthy pigs weighing between 26 and 29 kg were selected for surgery. Non-specialized surgeons performed emergency hemostasis, cholecystectomy, and renal vein ligation with remote assistance using the double-surgeon cockpits and specialized surgeons performed actual telesurgery. Additionally, the impact of adding internet protocol security (IPsec) encryption to the internet protocol-virtual private network (IP-VPN) line on communication was evaluated to address clinical security concerns.

RESULTS

The average time required for remote emergency hemostasis with the double-surgeon cockpit system was 10.64 s. A non-specialized surgeon could safely perform cholecystectomy or renal vein ligation with remote assistance. Global Evaluative Assessment of Robotic Skills and System Usability Scale scores were higher for telesurgical support-assisted surgery by a non-specialized surgeon using the double-surgeon cockpits than for telesurgery performed by a specialized surgeon without the double-cockpit system. Adding IPsec encryption to the IP-VPN did not have a significant impact on communication.

CONCLUSION

Telesurgical support through our double-surgeon cockpit system is feasible as first step toward clinical telesurgery.

Convergent genomic diversity and novel BCAA metabolism in intrahepatic cholangiocarcinoma

BACKGROUND

Driver alterations may represent novel candidates for driver gene-guided therapy; however, intrahepatic cholangiocarcinoma (ICC) with multiple genomic aberrations makes them intractable. Therefore, the pathogenesis and metabolic changes of ICC need to be understood to develop new treatment strategies. We aimed to unravel the evolution of ICC and identify ICC-specific metabolic characteristics to investigate the metabolic pathway associated with ICC development using multiregional sampling to encompass the intra- and inter-tumoral heterogeneity.

METHODS

We performed the genomic, transcriptomic, proteomic and metabolomic analysis of 39-77 ICC tumour samples and eleven normal samples. Further, we analysed their cell proliferation and viability.

RESULTS

We demonstrated that intra-tumoral heterogeneity of ICCs with distinct driver genes per case exhibited neutral evolution, regardless of their tumour stage. Upregulation of BCAT1 and BCAT2 indicated the involvement of 'Val Leu Ile degradation pathway'. ICCs exhibit the accumulation of ubiquitous metabolites, such as branched-chain amino acids including valine, leucine, and isoleucine, to negatively affect cancer prognosis. We revealed that this metabolic pathway was almost ubiquitously altered in all cases with genomic diversity and might play important roles in tumour progression and overall survival.

CONCLUSIONS

We propose a novel ICC onco-metabolic pathway that could enable the development of new therapeutic interventions.

Abstract 5230: Comprehensive genetic analysis using clinical specimens of gastric adenocarcinoma and proximal polyposis of stomach

Background and Purpose: Gastric adenocarcinoma and proximal polyposis (GAPPS) is an autosomal dominant genetic disorder that causes gastric carcinoma from fundus gland polyposis. Although germline mutation of APC promoter 1B was reported as a pathogenic variant in 2016, there are still many unknowns about the carcinogenesis. In this study, we performed a comprehensive Next generation sequencing (NGS) analysis of GAPPS clinical specimens to investigate the molecular profile characteristic of carcinogenesis.

Patients and Methods: Seven cases from three GAPPS families experienced in our department were included in this study. In each case, tissues were collected from normal mucosa, polyps, and carcinoma,

and FFPE and fresh-frozen samples were prepared. After pathological diagnosis was performed on each sample, RNA and DNA were extracted and analyzed based on data obtained by next generation sequence (NGS).

Results: In the RNA sequence, gene expression analysis was performed on 45 pathologically diagnosed samples, which were classified into four clusters by K-means clustering. Gene Set Enrichment Analysis (GSEA) of the four clusters showed that cancer-related genes such as p53 and KRAS were significantly enriched in the cluster of cancer, and genes related to immune response were significantly enriched in the cluster of cancer compared to the and clusters of polyp and normal. Gene mutation analysis using whole-exome sequence (read depth/coverage&gt;20) confirmed mutation of APC promoter 1B in all samples. On the other hand, in tumor samples (N=10), the percentage of mutation of genes previously suggested to be associated with GAPPS (TP53, FBXW7, GNAS, and KRAS) were 50%, 0%, 30%, and 60%, respectively.

Conclusion: Comprehensive gene expression analysis by RNA sequence and whole-exome sequence was performed using clinical samples of GAPPS. In the future, we plan to identify specific gene-pathways involved in carcinogenesis.

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Citation Format: Chihiro Matsumoto, Masaaki Iwatsuki, Koshi Mimori, Hideo Baba. Comprehensive genetic analysis using clinical specimens of gastric adenocarcinoma and proximal polyposis of stomach. [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 5230.

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.

Abstract 101: Convergent genomic diversity and novel oncogenic metabolism in intrahepatic cholangiocarcinoma

Background & Aim: Intrahepatic cholangiocarcinoma(ICC) accounts for about 5% of all primary liver cancer and is reported to be common in Southeast Asia and parts of Chile, but in recent years it has been increasing in other areas including Europe and the United States. ICC leads to a dismal outcome as the commonly used chemotherapy exhibit purely palliative effects on ICC, enabling only a limited improvement in survival until today. As ICC harbors few actionable target genes with inter-tumor genomic heterogeneity, ICC is considered to be one of the most intractable malignancies of all. Therefore, we implemented the multi-omics analysis especially with comprehension of the oncogenic metabolic changes to confer new treatment strategies. This study aims to unravel the evolution of ICC and identify ICC-specific metabolic pathways and essential targets for eradicating ICC.

Approach: We collected 12 primary ICC cases and 77 specimens and conducted a multi-omics approach, including genomics, transcriptomics, proteomics, and metabolomics for each material.

Results: We demonstrated that intra-tumoral heterogeneity of ICCs with distinct driver genes per case indicates a “neutral evolution manner”, regardless of their tumor stage. Upregulation of BCAT1 and BCAT2 might enrich the ‘branched-chain amino acids (BCAA), such as Val, Leu, and Ile degradation pathway’. ICCs cases with the accumulated ubiquitous metabolites, BCAA exhibited poorer prognosis than those cases without BCAA accumulation significantly.

Conclusions: Regardless of the inter-tumor heterogeneity in genomic aberrations among ICC cases, we discovered the ubiquitous enrichment of the BCAA metabolic pathway in each tumor. We propose a novel ICC onco-metabolic pathway that could enable the development of new therapeutic interventions.

Citation Format: Yusuke Nakano, Akihiro Kitagawa, Masahiro Hashimoto, Tadashi Abe, Yuichi Hisamatsu, Takeo Toshima, Yusuke Yonemura, Takaaki Masuda, Akira Inoue, Hidetoshi Eguchi, Yuichiro Doki, Koshi Mimori. Convergent genomic diversity and novel oncogenic metabolism in intrahepatic cholangiocarcinoma [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 101.

Disclosing quantitative RT-PCR raw data during manuscript submission:a call for action

Accuracy and transparency of scientific data are becoming more and more relevant with the increasing concern regarding the evaluation of data reproducibility in many research areas. This concern is also true for quantifying coding and non-coding RNAs, with the remarkable increase in publications reporting RNA profiling and sequencing studies. To address the problem, we propose the following recommendations: 1) accurate documentation of experimental procedures in Materials and Methods (and not only in the supplementary information, as many journals have a strict mandate for making Materials and Methods as visible as possible in the main text); 2) submission of RT-qPCR raw data for all experiments reported; and 3) adoption of a unified, simple format for submitted RT-qPCR raw data. The Real-time PCR Data Essential Spreadsheet Format (RDES) was created for this purpose.

Dynamic Changes in Peripheral Systemic Immunity Markers During Chemotherapy in HER2-negative Advanced Breast Cancer

BACKGROUND/AIM

The immune system has a pivotal role in modulating the response to chemotherapy in breast cancer (BC). However, the immune status during chemotherapy remains unclear. We evaluated the sequential changes in peripheral systemic immunity markers in BC patients treated with various chemotherapeutic agents.

MATERIALS AND METHODS

We examined the correlation between the peripheral systemic immunity markers, neutrophil-to-lymphocyte ratio (NLR), absolute lymphocyte count (ALC) and the local cytolytic activity (CYT) score obtained by quantitative reverse-transcription polymerase chain reaction of 84 preoperative BC patients. Next, we observed the sequential changes in the peripheral systemic immunity markers during treatment with four anticancer drugs: oral 5-fluorouracil derivative; S-1, epirubicin plus cyclophosphamide; paclitaxel plus the anti-vascular endothelial growth factor antibody bevacizumab, and eribulin in 172 HER2-negative advanced BC patients. Finally, we examined the correlation between the changes in the peripheral systemic immunity markers, time to treatment failure (TTF) and progression-free survival (PFS).

RESULTS

A negative correlation was found between ALC and NLR. ALC-low and NLR-high cases were positively associated with CYT score-low cases. The ratio of ALC-increase and NLR-decrease varies depending on the anticancer drugs used. The responder group (TTF ≥3 months) had a higher NLR-decrease ratio than the nonresponder group (TTF <3 months). Patients with a high NLR-decrease ratio showed higher PFS.

CONCLUSION

The change in ALC or NLR varies according to the anticancer drugs, suggesting differential immunomodulatory effects of the drugs. Furthermore, the change in NLR reflects the therapeutic efficacy of chemotherapy in advanced BC.

Spatial and single-cell transcriptomics decipher the cellular environment containing HLA-G+ cancer cells and SPP1+ macrophages in colorectal cancer

The cellular interactions in the tumor microenvironment of colorectal cancer (CRC) are poorly understood, hindering patient treatment. In the current study, we investigate whether events occurring at the invasion front are of particular importance for CRC treatment strategies. To this end, we analyze CRC tissues by combining spatial transcriptomics from patients with a public single-cell transcriptomic atlas to determine cell-cell interactions at the invasion front. We show that CRC cells are localized specifically at the invasion front. These cells induce human leukocyte antigen G (HLA-G) to produce secreted phosphoprotein 1 (SPP1)+ macrophages while conferring CRC cells with anti-tumor immunity, as well as proliferative and invasive properties. Taken together, these findings highlight the signaling between CRC cell populations and stromal cell populations at the cellular level.

Trousseau's Syndrome with Advanced Neuroendocrine Carcinoma of Colon: A Case Report

Here, we present a 69-year-old female with advanced neuroendocrine carcinoma (NEC) of colon with multiple liver, bone, and kidney metastases who developed Trousseau's syndrome. The patient received etoposide plus cisplatin (EP) as the first-line therapy; however, after single administration of EP, she developed the severe lower-limb edema and EP was considered to be intolerable. Etoposide plus carboplatin was administered as the second-line therapy and after 3 cycles of administration, the progressive disease (PD) was confirmed and 5-fluorouracil + leucovorin + irinotecan (FOLFIRI) plus ramucirumab was administered as the third-line therapy. However, PD was confirmed after 3 cycles of the therapy, and she was to receive the best supportive care and was hospitalized in our hospital. Four weeks after hospitalization, mild impaired consciousness and dysarthria were observed. Blood tests showed coagulation abnormalities including elevation of plasma fibrin/fibrinogen degradation products (FDPs) and D-dimer levels, and the diffusion-weighted image of magnetic resonance imaging (MRI) of the head showed multiple cerebral infarcts. She was diagnosed with Trousseau's syndrome due to the progression of NEC and intravenous unfractionated heparin was administered as anticoagulant therapy. After the administration of heparin, plasma FDP and D-dimer levels decreased; however, due to the progression of NEC, the patient died 6 weeks after hospitalization. This is the first report of NEC of the colon that developed Trousseau's syndrome.

Identification of the Minimum Combination of Serum microRNAs to Predict the Recurrence of Colorectal Cancer Cases

BACKGROUND

Serum microRNAs (miRNAs) have been recognized as potential stable biomarkers for various types of cancer. Considering the clinical applications, there are certain critical requirements, such as minimizing the number of miRNAs, reproducibility in a longitudinal clinical course, and superiority to conventional tumor markers, such as carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9. This study aimed to identify serum miRNAs that indicate the recurrence of colorectal cancer (CRC), surpassing inter-tumor heterogeneity.

METHODS

We conducted an analysis of 434 serum samples from 91 patients with CRC and 71 healthy subjects. miRNAs were obtained from Toray Co., Ltd, and miRNA profiles were analyzed using a three-step approach. miRNAs that were highly expressed in patients with CRC than in the healthy controls in the screening phase, and those that were highly expressed in the preoperative samples than in the 1-month postoperative samples in the discovery phase, were extracted. In the validation phase, the extracted miRNAs were evaluated in 323 perioperative samples, in chronological order.

RESULTS

A total of 12 miRNAs (miR-25-3p, miR-451a, miR-1246, miR-1268b, miR-2392, miR-4480, miR-4648, miR-4732-5p, miR-4736, miR-6131, miR-6776-5p, and miR-6851-5p) were significantly concordant with the clinical findings of tumor recurrence, however their ability to function as biomarkers was comparable with CEA. In contrast, the combination of miR-1246, miR-1268b, and miR-4648 demonstrated a higher area under the curve (AUC) than CEA. These three miRNAs were upregulated in primary CRC tissues.

CONCLUSION

We identified ideal combinatorial miRNAs to predict CRC recurrence.

Regulome-based characterization of drug activity across the human diseasome

Drugs are expected to recover the cell system away from the impaired state to normalcy through disease treatment. However, the understanding of gene regulatory machinery underlying drug activity or disease pathogenesis is far from complete. Here, we perform large-scale regulome analysis for various diseases in terms of gene regulatory machinery. Transcriptome signatures were converted into regulome signatures of transcription factors by integrating publicly available ChIP-seq data. Regulome-based correlations between diseases and their approved drugs were much clearer than the transcriptome-based correlations. For example, an inverse correlation was observed for cancers, whereas a positive correlation was observed for immune system diseases. After demonstrating the usefulness of the regulome-based drug discovery method in terms of accuracy and applicability, we predicted new drugs for nonsmall cell lung cancer and validated the anticancer activity in vitro. The proposed method is useful for understanding disease–disease relationships and drug discovery.

Persistent epigenetic alterations in transcription factors after a sustained virological response in hepatocellular carcinoma

Background and Aim

The risk of hepatocellular carcinoma (HCC) persists in a condition of sustained virologic response (SVR) after hepatitis C virus (HCV) eradication. Comprehensive molecular analyses were performed to test the hypothesis that epigenetic abnormalities present after an SVR play a role in hepatocarcinogenesis.

Methods

Whole-genome methylome and RNA sequencing were performed on HCV, SVR, and healthy liver tissue. Integrated analysis of the sequencing data focused on expression changes in transcription factors and their target genes, commonly found in HCV and SVR. Identified expression changes were validated in demethylated cultured HCC cell lines and an independent validation cohort.

Results

The coincidence rates of the differentially methylated regions between the HCV and SVR groups were 91% in the hypomethylated and 71% in the hypermethylated regions in tumorous tissues, and 37% in the hypomethylated and 36% in the hypermethylated regions in non-tumorous tissues. These results indicate that many epigenomic abnormalities persist even after an SVR was achieved. Integrated analysis identified 61 transcription factors and 379 other genes that had methylation abnormalities and gene expression changes in both groups. Validation cohort specified gene expression changes for 14 genes, and gene ontology pathway analysis revealed apoptotic signaling and inflammatory response were associated with these genes.

Conclusion

This study demonstrates that DNA methylation abnormalities, retained after HCV eradication, affect the expression of transcription factors and their target genes. These findings suggest that DNA methylation in SVR patients may be functionally important in carcinogenesis, and could serve as biomarkers to predict HCC occurrence.

Molecular and clinicopathological differences between depressed and protruded T2 colorectal cancer

Background

Colorectal cancer (CRC) can be classified into four consensus molecular subtypes (CMS) according to genomic aberrations and gene expression profiles. CMS is expected to be useful in predicting prognosis and selecting chemotherapy regimens. However, there are still no reports on the relationship between the morphology and CMS.

Methods

This retrospective study included 55 subjects with T2 CRC undergoing surgical resection, of whom 30 had the depressed type and 25 the protruded type. In the classification of the CMS, we first defined cases with deficient mismatch repair as CMS1. And then, CMS2/3 and CMS4 were classified using an online classifier developed by Trinh et al. The staining intensity of CDX2, HTR2B, FRMD6, ZEB1, and KER and the percentage contents of CDX2, FRMD6, and KER are input into the classifier to obtain automatic output classifying the specimen as CMS2/3 or CMS4.

Results

According to the results yielded by the online classifier, of the 30 depressed-type cases, 15 (50%) were classified as CMS2/3 and 15 (50%) as CMS4. Of the 25 protruded-type cases, 3 (12%) were classified as CMS1 and 22 (88%) as CMS2/3. All of the T2 CRCs classified as CMS4 were depressed CRCs. More malignant pathological findings such as lymphatic invasion were associated with the depressed rather than protruded T2 CRC cases.

Conclusions

Depressed-type T2 CRC had a significant association with CMS4, showing more malignant pathological findings such as lymphatic invasion than the protruded-type, which could explain the reported association between CMS4 CRC and poor prognosis.

Identification of serum microRNAs as potential diagnostic biomarkers for detecting precancerous lesions of gastric cancer

Aim

Gastric mucosal changes associated with chronic gastritis are known to be precancerous lesions of gastric cancer. We aimed to identify individuals with a high risk of gastric cancer by detection of microRNAs (miRNA) in the blood as biomarkers.

Methods

Of 1206 individuals screened, 144 who were positive for Helicobacter pylori (H. pylori) by the serum antibody test and who underwent endoscopy were the subjects of this study. For the gross assessment of mucosal inflammation, we applied the Kimura-Takemoto classification, in which normal mucosa was defined as grade 0, and atrophy was categorized as grade 1 (C-1 and C-2), grade 2 (C-3 and O-1), and grade 3 (O-2 and O-3). Serum samples were divided into two phases and used for miRNA microarray profiling. We compared the expression of miRNAs in grade 3 mucosa and other grades. Expression in gastric cancer was confirmed with TCGA data.

Results

miR-196b-3p was significantly upregulated, and miR-92a-2-5p was downregulated (P < .05 and q < 0.2). TCGA data showed a high expression of miR-196b-3p in gastric cancer cases (P < .001). Comparing grade 3 and the others, the area under the receiver operating characteristic curve using the detected miRNAs was as high as about 0.7. Furthermore, the combination of miRNAs resulted in higher accuracy. In terms of the significance of the combinatory mRNAs, the combination of three miRNAs (miR-196b-3p, miR-92a-2-5p, and miR-6791-3p) revealed high sensitivity and specificity, with the area under the curve exceeding 0.8.

Conclusion

The identified combinatory miRNAs may represent promising biomarkers of precancerous lesions in gastric cancer.

Clinical Significance of Acylphosphatase 1 Expression in Combined HCC-iCCA, HCC, and iCCA

BACKGROUND

Combined hepatocellular and cholangiocarcinoma is a rare primary liver cancer with histological features of both hepatocellular carcinoma and intrahepatic cholangiocarcinoma. Little is known about the prognostic features and molecular mechanism of cHCC-iCCA. Acylphosphatase 1 is a cytosolic enzyme that produces acetic acid from acetyl phosphate and plays an important role in cancer progression.

AIMS

We evaluated the clinical significance of ACYP1 expression in cHCC-iCCA, HCC, and iCCA.

METHODS

ACYP1 immunohistochemistry was performed in 39 cases diagnosed with cHCC-iCCA. The prognosis was evaluated in three different cohorts (cHCC-iCCA, HCC, and iCCA). The relationships between ACYP1 expression and cell viability, migration, invasiveness, and apoptosis were examined using siRNA methods in vitro. In vivo subcutaneous tumor volumes and cell apoptosis were evaluated after downregulation of ACYP1 expression.

RESULTS

Almost half of the patients with cHCC-iCCA were diagnosed with high ACYP1 expression. In all three cohorts, the cases with high ACYP1 expression had significantly lower overall survival, and high ACYP1 expression was identified as an independent prognostic factor. Downregulation of ACYP1 reduced the proliferative capacity, migration, and invasiveness of both HCC and iCCA cells. Moreover, knockdown of ACYP1 increased the ratio of apoptotic cells and decreased the expression of anti-apoptosis proteins. In vivo tumor growth was significantly inhibited by the transfection of ACYP1 siRNA, and the number of apoptotic cells increased.

CONCLUSION

High ACYP1 expression could influence the prognosis of cHCC-iCCA, HCC, and iCCA patients. In vitro ACYP1 expression influences the tumor growth and cell viability in both HCC and iCCA by regulating anti-apoptosis proteins.

Dosimetry of Occupational Eye Lens Dose Using a Novel Direct Eye Dosimeter, DOSIRIS, during Interventional Radiology Procedures

In response to the recommendation by the International Commission on Radiological Protection to lower the equivalent eye dose limit, the Japanese Government in April 2021 lowered the equivalent dose limit for the eye lens for occupational exposure. A considerable number of interventional radiology operators are exposed to levels above the new limit. For this reason, a need exists to more accurately evaluate eye lens dose in interventional radiology operators by using a novel direct eye dosimeter, the DOSIRIS™(IRSN, France), which is capable of measuring a 3-mm dose equivalent under protective glasses. The DOSIRIS is a thermoluminescent dosimeter that exhibits good energy dependence and better directional properties than other dosimeters. Dosimetry using DOSIRIS might be accurate and compatible with the latest regulations.

Artificial intelligence-assisted drug repurposing via "chemical-induced gene expression ranking"

Drug repurposing using artificial intelligence algorithms is a powerful technique that leverages existing datasets to find new medical applications for approved drugs. Pham et al. developed CIGER, a deep learning framework to overcome unreliable data in the datasets and present repositioned drugs against pancreatic cancer.

Nano-scale physical properties characteristic to metastatic intestinal cancer cells identified by high-speed scanning ion conductance microscope

Recent genetic studies have indicated relationships between gene mutations and colon cancer phenotypes. However, how physical properties of tumor cells are changed by genetic alterations has not been elucidated. We examined genotype-defined mouse intestinal tumor-derived cells using a high-speed scanning ion conductance microscope (HS-SICM) that can obtain high-resolution live images of nano-scale topography and stiffness. The tumor cells used in this study carried mutations in Apc (A), Kras (K), Tgfbr2 (T), Trp53 (P), and Fbxw7 (F) in various combinations. Notably, high-metastatic cancer-derived cells carrying AKT mutations (AKT, AKTP, and AKTPF) showed specific ridge-like morphology with active membrane volume change, which was not found in low-metastatic and adenoma-derived cells. Furthermore, the membrane was significantly softer in the metastatic AKT-type cancer cells than other genotype cells. Importantly, a principal component analysis using RNAseq data showed similar distributions of expression profiles and physical properties, indicating a link between genetic alterations and physical properties. Finally, the malignant cell-specific physical properties were confirmed by an HS-SICM using human colon cancer-derived cells. These results indicate that the HS-SICM analysis is useful as a novel diagnostic strategy for predicting the metastatic ability of cancer cells.

Successful Treatment with Hepatic Arterial Infusion Chemotherapy in a Breast Cancer Patient with Multiple Liver Metastases Who Declined Systemic Therapy

Despite improvements in systemic medical therapy (ST), liver metastases (LMs) are a poor prognostic factor in metastatic breast cancer (MBC) patients. We describe a MBC patient with predominant LMs treated with hepatic arterial infusion chemotherapy (HAIC) who declined ST. Moreover, we assessed general health status during treatment using C-reactive protein (CRP)/albumin ratio (CAR) and peripheral platelet count × CRP multiplier (P-CRP), well-known indicators of systemic inflammatory response. A 64-year-old woman who underwent a total mastectomy with axillary lymph node dissection for an HR-positive, HER2-negative infiltrating ductal BC developed multiple liver, lung, lymph node, and bone metastases. She received ST including paclitaxel plus the anti-vascular endothelial growth factor antibody, bevacizumab, hormone therapy with high-dose toremifene, the oral 5-fluorouracil derivative, S-1, and eribulin. She then declined ST because of the toxicity or decreased treatment motivation thereof, and opted for HAIC with 5FU plus epirubicin followed by Taxane for 1 year and 1 month. Computed tomography revealed a partial response or stable disease in the liver and slow progression in other sites without symptoms or side effects and decreased CEA and CA15-3 levels. The CAR and P-CRP remained low. She survived for 1 year and 3 months after the start of HAIC. This case reveals that HAIC may be an option for advanced BC patients with LMs who cannot receive ST.

Fanconi Anemia Complementation Group E (FANCE), a DNA Repair-Related Gene, Is a Potential Marker of Poor Prognosis in Hepatocellular Carcinoma

INTRODUCTION

Fanconi anemia complementation group E (FANCE) is a Fanconi anemia (FA) pathway gene that regulates DNA repair. We evaluated the clinical relevance of FANCE expression in hepatocellular carcinoma (HCC).

METHODS

First, the associations between the expression of FA pathway genes including FANCE and clinical outcomes in HCC patients were analyzed in two independent cohorts: The Cancer Genome Atlas (TCGA, n = 373) and our patient cohort (n = 53). Localization of FANCE expression in HCC tissues was observed by immunohistochemical staining. Gene set enrichment analysis (GSEA) and gene network analysis (SiGN_BN) were conducted using the TCGA dataset. Next, an in vitro proliferation assay was performed using FANCE-knockdown HCC cell lines (HuH7 and HepG2). The association between mRNA expression of FANCE and that of DNA damage response genes in HCC was analyzed using TCGA and Cancer Cell Line Encyclopedia datasets. Finally, the association between FANCE mRNA expression and overall survival (OS) in various digestive carcinomas was analyzed using TCGA data.

RESULTS

FANCE was highly expressed in HCC cells. Multivariate analysis indicated that high FANCE mRNA expression was an independent factor predicting poor OS. GSEA revealed a positive relationship between enhanced FANCE expression and E2F and MYC target gene expression in HCC tissues. FANCE knockdown attenuated the proliferation of HCC cells, as well as reduced cdc25A expression and elevated histone H3 pSer10 expression. SiGN_BN revealed that FANCE mRNA expression was positively correlated with DNA damage response genes (H2AFX and CHEK1) in HCC tissues. Significant effects of high FANCE expression on OS were observed in hepatobiliary pancreatic carcinomas, including HCC.

CONCLUSIONS

FANCE may provide a potential therapeutic target and biomarker of poor prognosis in HCC, possibly by facilitating tumor proliferation, which is mediated partly by cell cycle signaling activation.

GET4 is a novel driver gene in colorectal cancer that regulates the localization of BAG6, a nucleocytoplasmic shuttling protein

Colorectal cancer (CRC) is one of the most common types of cancer and a significant cause of cancer mortality worldwide. Further improvements of CRC therapeutic approaches are needed. BCL2‐associated athanogene 6 (BAG6), a multifunctional scaffold protein, plays an important role in tumor progression. However, regulation of BAG6 in malignancies remains unclear. This study showed that guided entry of tail‐anchored proteins factor 4 (GET4), a component of the BAG6 complex, regulates the intercellular localization of BAG6 in CRC. Furthermore, GET4 was identified as a candidate driver gene on the short arm of chromosome 7, which is often amplified in CRC, by our bioinformatics approach using the CRC dataset from The Cancer Genome Atlas. Clinicopathologic and prognostic analyses using CRC datasets showed that GET4 was overexpressed in tumor cells due to an increased DNA copy number. High GET4 expression was an independent poor prognostic factor in CRC, whereas BAG6 was mainly overexpressed in the cytoplasm of tumor cells without gene alteration. The biological significance of GET4 was examined using GET4 KO CRC cells generated with CRISPR‐Cas9 technology or transfected CRC cells. In vitro and in vivo analyses showed that GET4 promoted tumor growth. It appears to facilitate cell cycle progression by cytoplasmic enrichment of BAG6‐mediated p53 acetylation followed by reduced p21 expression. In conclusion, we showed that GET4 is a novel driver gene and a prognostic biomarker that promotes CRC progression by inducing the cytoplasmic transport of BAG6. GET4 could be a promising therapeutic molecular target in CRC.

Clinical usefulness of a novel fluorescence technique for the intraoperative diagnosis of surgical margins in patients with breast cancer

In both 5- and 15-min data, FI was significantly higher in malignant tissues than in benign tissues. The diagnostic accuracy was similar at 5 and 15 min. Therefore, the 5-min FI was enough applying in the further analyses.

The Evolving Genomic Landscape of Esophageal Squamous Cell Carcinoma Under Chemoradiotherapy

Esophageal squamous cell carcinoma (ESCC) often recurs after chemoradiotherapy, and the prognosis of ESCC after chemoradiotherapy has not improved over the past few decades. The mutation process in chemoradiotherapy-resistant clones and the functional relevance of genetic alterations remain unclear. To address these problems, we performed whole-exome sequencing of 52 tumor samples from 33 patients with ESCC who received radiotherapy combined with 5-fluorouracil/platinum. In multiregion analyses of pretreatment and locally recurrent lesions from five cases, most driver gene-altered clones remained under chemoradiotherapy selection pressure, while few driver gene alterations were acquired at recurrence. The mutation signatures of recurrent ESCC, including increased deletion frequency and platinum dose-dependent base substitution signatures, were substantially different from those of primary ESCC and reflected the iatrogenic impacts of chemoradiotherapy. Single-region analysis of 28 pretreatment tumors indicated that focal copy-number gain at the MYC locus was significantly associated with poor progression-free survival and overall survival after chemoradiotherapy. MYC gain remained throughout the chemoradiotherapy course and potentially contributes to intrinsic resistance to chemoradiotherapy. Consistent with these findings, MYC copy number and mRNA and protein levels in ESCC cell lines correlated positively with resistance to radiotherapy, and MYC knockdown improved sensitivity to radiotherapy. Overall, these data characterize the clonal evolution process induced by chemoradiotherapy and clinically relevant associations for genetic alterations in ESCC. These findings increase our understanding of therapeutic resistance and support the rationale for precision chemoradiotherapy. SIGNIFICANCE: Whole-exome sequencing reveals the genetic evolution of ESCC during chemoradiotherapy, highlighting MYC gain in pretreatment tumors as a potential marker of therapy resistance.

Oxysterol binding protein-like 3 (OSBPL3) is a novel driver gene that promotes tumor growth in part through R-Ras/Akt signaling in gastric cancer

Gastric cancer (GC) is one of the most lethal malignant tumors. To improve the prognosis of GC, the identification of novel driver genes as therapeutic targets is in urgent need. Here, we aimed to identify novel driver genes and clarify their roles in gastric cancer. OSBPL3 was identified as a candidate driver gene by in silico analysis of public genomic datasets. OSBPL3 expression was analyzed by RT-qPCR and immunohistochemistry in GC cells and tissues. The biological functions and mechanisms of OSBPL3 in GC were examined in vitro and in vivo using GC cells. The association between OSBPL3 expression and clinical outcome in GC patients was also evaluated. Overexpression of OSBPL3 was detected in GC cells with OSBPL3 DNA copy number gains and promoter hypomethylation. OSBPL3-knockdown reduced GC cell growth in vitro and in vivo by inhibiting cell cycle progression. Moreover, an active Ras pull-down assay and western blotting demonstrated that OSBPL3 activates the R-Ras/Akt signaling pathway in GC cells. In a clinical analysis of two GC datasets, high OSBPL3 expression was predictive of a poor prognosis. Our findings suggest that OSBPL3 is a novel driver gene stimulating the R-Ras/Akt signaling pathway and a potential therapeutic target in GC patients.

Single-cell DNA and RNA sequencing reveals the dynamics of intra-tumor heterogeneity in a colorectal cancer model

BACKGROUND

Intra-tumor heterogeneity (ITH) encompasses cellular differences in tumors and is related to clinical outcomes such as drug resistance. However, little is known about the dynamics of ITH, owing to the lack of time-series analysis at the single-cell level. Mouse models that recapitulate cancer development are useful for controlled serial time sampling.

RESULTS

We performed single-cell exome and transcriptome sequencing of 200 cells to investigate how ITH is generated in a mouse colorectal cancer model. In the model, a single normal intestinal cell is grown into organoids that mimic the intestinal crypt structure. Upon RNAi-mediated downregulation of a tumor suppressor gene APC, the transduced organoids were serially transplanted into mice to allow exposure to in vivo microenvironments, which play relevant roles in cancer development. The ITH of the transcriptome increased after the transplantation, while that of the exome decreased. Mutations generated during organoid culture did not greatly change at the bulk-cell level upon the transplantation. The RNA ITH increase was due to the emergence of new transcriptional subpopulations. In contrast to the initial cells expressing mesenchymal-marker genes, new subpopulations repressed these genes after the transplantation. Analyses of colorectal cancer data from The Cancer Genome Atlas revealed a high proportion of metastatic cases in human subjects with expression patterns similar to the new cell subpopulations in mouse. These results suggest that the birth of transcriptional subpopulations may be a key for adaptation to drastic micro-environmental changes when cancer cells have sufficient genetic alterations at later tumor stages.

CONCLUSIONS

This study revealed an evolutionary dynamics of single-cell RNA and DNA heterogeneity in tumor progression, giving insights into the mesenchymal-epithelial transformation of tumor cells at metastasis in colorectal cancer.

Radiology- and gene-based risk stratification in small renal cell carcinoma: A preliminary study

PURPOSE

Most small renal cell carcinomas (small RCCs) will remain indolent after detection, but some stage I RCCs still metastasize. There are no risk-stratification imaging factors that could be used to identify poor-prognosis patients based on genomic profiling. Here, we evaluated the relationships between imaging parameters and RNA expressions in small RCC and attempted to identify imaging factors that could be used as effective biomarkers.

METHODS

We acquired biopsy specimens of 18 clear cell carcinomas that had undergone perfusion CT (pCT) and MRI between April 2018 and March 2019. We performed RNA sequencing, assessed RNA expressions, and calculated each tumor's cell-cycle progression (CCP) score, which has prognostic value in predicting metastatic progression. We classified the tumors into two groups: clear cell type A (ccA) and type B (ccB). CcA has better survival compared to ccB. We evaluated the following characteristics of each tumor: tumor size, presence of pseudocapsule, and fat. We used the pCT and MRI to measure each tumor's volume transfer constant (Ktrans), rate constant (Kep), extracellular extravascular volume fraction (VE), fractional plasma volume (VP), and apparent diffusion coefficient (ADC). The correlations between these small RCC imaging parameters and the tumor size and RNA expressions were determined.

RESULTS

The tumor size was significantly correlated with Kep and inversely correlated with VE, VP, ADC, and hallmark angiogenesis. The CCP score was significantly inversely correlated with Ktrans and Kep. The ccA tumors tended to show a pseudocapsule on MRI.

CONCLUSION

Tumor size was correlated with low perfusion, but not with prognostic factors based on genomic profiling. Imaging parameters (e.g., Ktrans and Kep) and tumor characteristics (e.g., pseudocapsule) may enable gene-based risk stratification in small RCC.

Modeling colorectal cancer evolution

Understanding cancer evolution provides a clue to tackle therapeutic difficulties in colorectal cancer. In this review, together with related works, we will introduce a series of our studies, in which we constructed an evolutionary model of colorectal cancer by combining genomic analysis and mathematical modeling. In our model, multiple subclones were generated by driver mutation acquisition and subsequent clonal expansion in early-stage tumors. Among the subclones, the one obtaining driver copy number alterations is endowed with malignant potentials to constitute a late-stage tumor in which extensive intratumor heterogeneity is generated by the accumulation of neutral mutations. We will also discuss how to translate our understanding of cancer evolution to a solution to the problem related to therapeutic resistance: mathematical modeling suggests that relapse caused by acquired resistance could be suppressed by utilizing clonal competition between sensitive and resistant clones. Considering the current rate of technological development, modeling cancer evolution by combining genomic analysis and mathematical modeling will be an increasingly important approach for understanding and overcoming cancer.

Appropriate use of cancer comprehensive genome profiling assay using circulating tumor DNA

Comprehensive genomic profiling (CGP) is being increasingly used for the routine clinical management of solid cancers. In July 2018, the use of tumor tissue-based CGP assays became available for all solid cancers under the universal health insurance system in Japan. Several restrictions presently exist, such as patient eligibility and limitations on the opportunities to perform such assays. The clinical implementation of CGP based on plasma circulating tumor DNA (ctDNA) is also expected to raise issues regarding the selection and use of tissue DNA and ctDNA CGP. A Joint Task Force for the Promotion of Cancer Genome Medicine comprised of three Japanese cancer-related societies has formulated a policy proposal for the appropriate use of plasma CGP (in Japanese), available at https://www.jca.gr.jp/researcher/topics/2021/files/20210120.pdf, http://www.jsco.or.jp/jpn/user_data/upload/File/20210120.pdf, and https://www.jsmo.or.jp/file/dl/newsj/2765.pdf. Based on these recommendations, the working group has summarized the respective advantages and cautions regarding the use of tissue DNA CGP and ctDNA CGP with reference to the advice of a multidisciplinary expert panel, the preferred use of plasma specimens over tissue, and multiple ctDNA testing. These recommendations have been prepared to maximize the benefits of performing CGP assays and might be applicable in other countries and regions.

Cancer-associated Fibroblast-derived Spondin-2 Promotes Motility of Gastric Cancer Cells

BACKGROUND/AIM

Peritoneal dissemination (PD) occurs frequently in gastric cancer (GC) and is fatal. The interactions between tumor cells and stromal cells are critical for cancer progression. Our aim was to identify a novel PD-associated gene derived from stromal cells in GC.

MATERIALS AND METHODS

Among the candidate PD-associated genes identified in our previous study, we focused on spondin-2 (SPON2), an extracellular matrix-secreted protein. Clinicopathological and prognostic analyses of SPON2 mRNA expression were performed using GC datasets. Localization of SPON2 expression was assessed by immunohistochemistry. In vitro migration assay and immunofluorescence staining were also conducted using GC cell lines.

RESULTS

SPON2 was expressed in and secreted from cancer-associated fibroblasts in GC. High expression of SPON2 in tumor tissues was correlated with PD, tumor size and poor prognosis in GC. The motility of GC cells was increased by treatment with a SPON2 recombinant protein in vitro.

CONCLUSION

Cancer-associated fibroblast-derived SPON2 may promote PD, in part, by facilitating GC cell motility and serve as a predictive marker for PD in GC.

Mitotic checkpoint regulator RAE1 promotes tumor growth in colorectal cancer

Microtubules are among the most successful targets for anticancer therapy because they play important roles in cell proliferation as they constitute the mitotic spindle, which is critical for chromosome segregation during mitosis. Hence, identifying new therapeutic targets encoding proteins that regulate microtubule assembly and function specifically in cancer cells is critical. In the present study, we identified a candidate gene that promotes tumor progression, ribonucleic acid export 1 (RAE1), a mitotic checkpoint regulator, on chromosome 20q through a bioinformatics approach using datasets of colorectal cancer (CRC), including The Cancer Genome Atlas (TCGA). RAE1 was ubiquitously amplified and overexpressed in tumor cells. High expression of RAE1 in tumor tissues was positively associated with distant metastasis and was an independent poor prognostic factor in CRC. In vitro and in vivo analysis showed that RAE1 promoted tumor growth, inhibited apoptosis, and promoted cell cycle progression, possibly with a decreased proportion of multipolar spindle cells in CRC. Furthermore, RAE1 induced chemoresistance through its anti-apoptotic effect. In addition, overexpression of RAE1 and significant effects on survival were observed in various types of cancer, including CRC. In conclusion, we identified RAE1 as a novel gene that facilitates tumor growth in part by inhibiting apoptosis and promoting cell cycle progression through stabilizing spindle bipolarity and facilitating tumor growth. We suggest that it is a potential therapeutic target to overcome therapeutic resistance of CRC.

The novel driver gene ASAP2 is a potential druggable target in pancreatic cancer

Targeting mutated oncogenes is an effective approach for treating cancer. The 4 main driver genes of pancreatic ductal adenocarcinoma (PDAC) are KRAS, TP53, CDKN2A, and SMAD4, collectively called the "big 4" of PDAC, however they remain challenging therapeutic targets. In this study, ArfGAP with SH3 domain, ankyrin repeat and PH domain 2 (ASAP2), one of the ArfGAP family, was identified as a novel driver gene in PDAC. Clinical analysis with PDAC datasets showed that ASAP2 was overexpressed in PDAC cells based on increased DNA copy numbers, and high ASAP2 expression contributed to a poor prognosis in PDAC. The biological roles of ASAP2 were investigated using ASAP2-knockout PDAC cells generated with CRISPR-Cas9 technology or transfected PDAC cells. In vitro and in vivo analyses showed that ASAP2 promoted tumor growth by facilitating cell cycle progression through phosphorylation of epidermal growth factor receptor (EGFR). A repositioned drug targeting the ASAP2 pathway was identified using a bioinformatics approach. The gene perturbation correlation method showed that niclosamide, an antiparasitic drug, suppressed PDAC growth by inhibition of ASAP2 expression. These data show that ASAP2 is a novel druggable driver gene that activates the EGFR signaling pathway. Furthermore, niclosamide was identified as a repositioned therapeutic agent for PDAC possibly targeting ASAP2.