Microenvironmental changes in familial adenomatous polyposis during colorectal cancer carcinogenesis.

Familial adenomatous polyposis (FAP) is a heritable disease that increases the risk of colorectal cancer (CRC) development because of heterozygous mutations in APC. Little is known about the microenvironment of FAP. Here, single-cell RNA sequencing was performed on matched normal tissues, adenomas, and carcinomas from four patients with FAP. We analyzed the transcriptomes of 56,225 unsorted single cells, revealing the heterogeneity of each cell type, and compared gene expression among tissues. Then we compared the gene expression with that of sporadic CRC. Furthermore, we analyzed specimens of 26 FAP patients and 40 sporadic CRC patients by immunohistochemistry. Immunosuppressiveness of myeloid cells, fibroblasts, and regulatory T cells was upregulated even in the early stages of carcinogenesis. CD8+ T cells became exhausted only in carcinoma, although the cytotoxicity of CD8+ T cells was gradually increased according to the carcinogenic step. When compared with those in the sporadic CRC microenvironment, the composition and function of each cell type in the FAP-derived CRC microenvironment had differences. Our findings indicate that an immunosuppressive microenvironment is constructed from a precancerous stage in FAP.

Tumor-infiltrating monocytic myeloid-derived suppressor cells contribute to the development of an immunosuppressive tumor microenvironment in gastric cancer.

BACKGROUND: Gastric cancer (GC) is characterized by an immunosuppressive and treatment-resistant tumor immune microenvironment (TIME). Here, we investigated the roles of different immunosuppressive cell types in the development of the GC TIME. METHODS: Single-cell RNA sequencing (scRNA-seq) and multiplex immunostaining of samples from untreated or immune checkpoint inhibitor (ICI)-resistant GC patients were used to examine the correlation between certain immunosuppressive cells and the prognosis of GC patients. RESULTS: The results of the scRNA-seq analysis revealed that tumor-infiltrating monocytic myeloid-derived suppressor cells (TI-M-MDSCs) expressed higher levels of genes with immunosuppressive functions than other immunosuppressive cell types. Additionally, M-MDSCs in GC tissues expressed significantly higher levels of these markers than adjacent normal tissues. The M-MDSCs were most enriched in GC tissues relative to adjacent normal tissues. Among the immunosuppressive cell types assessed, the M-MDSCs were most enriched in GC tissues relative to adjacent normal tissues; moreover, their presence was most strongly associated with a poor prognosis. Immediate early response 3 (IER3), which we identified as a differentially expressed gene between M-MDSCs of GC and adjacent normal tissues, was an independent poor prognostic factor in GC patients (P = 0.0003). IER3+ M-MDSCs expressed higher levels of genes with immunosuppressive functions than IER3- M-MDSCs and were abundant in treatment-resistant GC patients. CONCLUSIONS: The present study suggests that TI-M-MDSCs, especially IER3+ ones, may play a predominant role in the development of the immunosuppressive and ICI-resistant GC TIME.

Tertiary lymphoid structures correlate with enhancement of antitumor immunity in esophageal squamous cell carcinoma.

BACKGROUND: Tertiary lymphoid structures (TLSs) are associated with a favorable prognosis in several cancers. However, the correlation between TLSs and outcomes of esophageal squamous cell carcinoma (ESCC) and the impact of TLSs on the tumor immune microenvironment (TIME) remain unknown. METHODS: We pathologically evaluated the significance of TLSs in ESCC focusing on TLS maturation using 180 ESCC specimens and performed single-cell RNA sequencing (scRNA-seq) using 14 ESCC tissues to investigate functional differences of immune cells according to TLS presence. RESULTS: TLS+ cases had better recurrence-free-survival (RFS) (p < 0.0001) and overall survival (OS) (p = 0.0016) compared with TLS- cases. Additionally, mature TLS+ cases had better RFS and OS compared with immature TLS+ cases (p = 0.019 and p = 0.015) and TLS- cases (p < 0.0001 and p = 0.0002). The scRNA-seq showed that CD8+ T cells in TLS+ tumors expressed high levels of cytotoxic signatures and antigen-presentation of dendritic cells (DCs) was enhanced in TLS+ tumors. Immunohistochemistry showed that the densities of tumor-infiltrating CD8+ T cells and DCs were significantly higher in TLS+ tumors than those in TLS- tumors. CONCLUSIONS: These data suggest the prognostic and functional significance of TLSs in ESCC and provides new insights into TLSs on the TIME.

Intratumor Fusobacterium nucleatum promotes the progression of pancreatic cancer via the CXCL1-CXCR2 axis.

Intratumor bacteria modify the tumor immune microenvironment and influence outcomes of various tumors. Periodontal pathogen Fusobacterium nucleatum has been detected in pancreatic cancer tissues and is associated with poor prognosis. However, it remains unclear how F. nucleatum affects pancreatic cancer. Here, we compared clinical features with F. nucleatum colonization in pancreatic cancer tissues. F. nucleatum was detected in 15.5% (13/84) of pancreatic cancer patients. The tumor size was significantly larger in the F. nucleatum-positive group than in the negative group. To clarify the biological effect of intratumor F. nucleatum on pancreatic cancer progression, we performed migration/invasion assays and cytokine array analysis of cancer cells cocultured with F. nucleatum. F. nucleatum promoted CXCL1 secretion from pancreatic cancer cells, leading to cancer progression through autocrine signaling. Intratumor F. nucleatum suppressed tumor-infiltrating CD8+ T cells by recruiting myeloid-derived suppressor cells (MDSCs) to the tumor in an F. nucleatum-injected subcutaneous pancreatic cancer mouse model, resulting in tumor progression. Furthermore, tumor growth accelerated by F. nucleatum was suppressed by MDSC depletion or cytokine inhibitors. Intratumor F. nucleatum promoted pancreatic cancer progression through autocrine and paracrine mechanisms of the CXCL1-CXCR2 axis. Blockade of the CXCL1-CXCR2 axis may be a novel therapeutic approach for patients with intratumor F. nucleatum-positive pancreatic cancer.

Neoadjuvant chemotherapy enhances anti-tumor immune response of tumor microenvironment in human esophageal squamous cell carcinoma.

Although chemotherapy has been an essential treatment for cancer, the development of immune checkpoint blockade therapy was revolutionary, and a comprehensive understanding of the immunological tumor microenvironment (TME) has become crucial. Here, we investigated the impact of neoadjuvant chemotherapy (NAC) on immune cells in the TME of human esophageal squamous cell carcinoma using single cell RNA-sequencing. Analysis of 30 fresh samples revealed that CD8+/CD4+ T cells, dendritic cells (DCs), and macrophages in the TME of human esophageal squamous cell carcinoma showed higher levels of an anti-tumor immune response in the NAC(+) group than in the NAC(-) group. Furthermore, the immune cells of the NAC(+) group interacted with each other resulting in enhanced anti-tumor immune response via various cytokines, including IFNG in CD8+/CD4+ T cells, EBI3 in DCs, and NAMPT in macrophages. Our results suggest that NAC potentially enhances the anti-tumor immune response of immune cells in the TME.

Single-cell transcriptome analysis reveals functional changes in tumour-infiltrating B lymphocytes after chemotherapy in oesophageal squamous cell carcinoma.

BACKGROUND: Tumour immune microenvironment is related with carcinogenesis and efficacy of immunotherapy. B cells play major roles in humoral immunity, but detailed functions of tumour-infiltrating B lymphocytes (TIL-Bs) are unknown. Therefore, our aim was to investigate the functional heterogeneity of TIL-Bs in oesophageal squamous cell carcinoma (ESCC) and lymph nodes (LNs) during chemotherapy. METHODS: Single-cell transcriptome analysis was performed on 23 specimens. We also performed immunohistochemical analysis of immunoglobulin κ C (IGKC), an antibody-secreting cell (ASC) marker, in 166 ESCC samples and evaluated the implication of IGKC in 2-year recurrence free survival (RFS) and 3-year overall survival (OS). RESULTS: A total of 81,246 cells were grouped into 24 clusters. We extracted B cell clusters based on canonical markers and identified 12 TIL-B subtypes in ESCC. We found that several functions, such as co-stimulation and CD40 signalling, were enhanced in TIL-Bs after chemotherapy. The proportion of naive B cells (NBCs) decreased and B cell activation genes were up-regulated in NBCs after chemotherapy. The proportion of ASCs in tumours increased with the loss of migratory abilities and antibody production in ASCs was promoted after chemotherapy. Differentially expressed genes up-regulated with chemotherapy in ASCs correlated with prolonged survival with oesophageal cancer (p = .028). In a metastatic LN, the ASC proportion increased and B cell differentiation was enhanced. In immunohistochemical analysis, RFS and OS of high IGKC expression cases were significantly better than those of low IGKC expression cases (RFS: p < .0001, OS: p < .0001). And in multivariable analysis, the expression of IGKC was an independent favourable prognostic factor for RFS (hazard ratio (HR): 0.23, 95% confidence interval (CI): 0.12-0.45, p < .0001) and OS (HR: 0.20, 95% CI: 0.086-0.47, p = .0002) in ESCC. CONCLUSIONS: Our findings provide novel insights for the heterogeneity of TIL-Bs during chemotherapy and will be useful to understand the clinical importance of TIL-Bs.

Clinical assessment of the GNAS mutation status in patients with intraductal papillary mucinous neoplasm of the pancreas.

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is characterized by cystic dilation of the pancreatic duct, caused by mucin hypersecretion, with slow progression via the adenoma-carcinoma sequence mechanism. Mutation of GNAS at codon 201 is found exclusively in IPMNs, occurring at a rate of 41-75%. Recent advances in molecular biological techniques have demonstrated that GNAS mutation might play a role in the transformation of IPMNs after the appearance of neoplastic cells, rather than in the tumorigenesis of IPMNs. GNAS mutation is observed frequently in the intestinal subtype of IPMNs with MUC2 expression, and less frequently in IPMNs with concomitant pancreatic ductal adenocarcinoma (PDAC). Research has focused on assessing GNAS mutation status in clinical practice using various samples. In this review, we discuss the clinical application of GNAS mutation assessment to differentiate invasive IPMNs from concomitant PDAC, examine the clonality of recurrent IPMNs in the remnant pancreas using resected specimens, and differentiate pancreatic cystic lesions using cystic fluid collected by endoscopic ultrasound-guided fine needle aspiration (EUS-FNA), duodenal fluid, and serum liquid biopsy samples.

Visualizing Energy Charge in Breast Carcinoma Tissues by MALDI Mass-spectrometry Imaging Profiles of Low-molecular-weight Metabolites.

BACKGROUND/AIM: Metabolomics is widely used for biomarker discovery, but conventional mass-spectrometry extraction procedures lose the spatial localization of metabolites. In this study, we directly analyzed breast carcinoma tissues embedded in frozen tissue microarrays (fTMAs) using MALDI mass-spectrometry imaging (MALDI-MSI). MATERIALS AND METHODS: A total of 119 breast tissues (84 carcinoma and 35 normal) were used. MSI data were extracted from each tissue. RESULTS: Overall, 185 of 1,915 peaks which were commonly detected in 60% of target areas were subjected to further analysis. One hundred and fifty-two peaks of carcinoma showed significantly higher intensity than normal. Comparing metabolite profiles from carcinoma and normal tissues, energy charge (EC) and the sum of adenosine phosphate compound (AXP) indicated significantly higher intensities in cancerous tissues than normal. But comparisons of EC and AXP among lymph node metastasis, tumor size and tumor subtypes indicated no significant differences. CONCLUSION: Breast carcinoma tissues had higher EC and AXP values than normal. MALDI-MSI could be a tool for characterizing breast carcinoma.

Calpain inhibitor calpeptin suppresses pancreatic cancer by disrupting cancer-stromal interactions in a mouse xenograft model.

Desmoplasia contributes to the aggressive behavior of pancreatic cancer. However, recent clinical trials testing several antifibrotic agents on pancreatic cancer have not shown clear efficacy. Therefore, further investigation of desmoplasia-targeting antifibrotic agents by another mechanism is needed. Calpeptin, an inhibitor of calpains, suppressed fibroblast function and inhibited fibrosis. In this study, we investigated the anticancer effects of calpeptin on pancreatic cancer. We investigated whether calpeptin inhibited tumor progression using a mouse xenograft model. We used quantitative RT-PCR to evaluate the expression of calpain-1 and calpain-2 mRNA in pancreatic cancer cells (PCCs) and pancreatic stellate cells (PSCs). We also undertook functional assays, including proliferation, migration, and invasion, to evaluate the inhibitory effects of calpeptin on PCCs and PSCs. Quantitative RT-PCR indicated that PCCs and PSCs expressed calpain-2 mRNA. Calpeptin reduced tumor volume (P = 0.0473) and tumor weight (P = 0.0471) and inhibited the tumor desmoplastic reaction (P < 0.001) in xenograft tumors in nude mice. Calpeptin also inhibited the biologic functions of PCCs and PSCs including proliferation (P = 0.017), migration (P = 0.027), and invasion (P = 0.035) in vitro. Furthermore, calpeptin reduced the migration of PCCs and PSCs by disrupting the cancer-stromal interaction (P = 0.0002). Our findings indicate that calpeptin is a promising antitumor agent for pancreatic cancer, due not only to its suppressive effect on PCCs and PSCs but also its disruption of the cancer-stromal interaction.

TM4SF1 as a prognostic marker of pancreatic ductal adenocarcinoma is involved in migration and invasion of cancer cells.

The cell surface protein Transmembrane 4 L6 family member 1 (TM4SF1) has been detected in various tumors, and its expression on tumor cells is implicated in cancer cell metastasis and patient prognosis. The role of TM4SF1 in malignant tumors remains poorly understood, particularly in pancreatic cancer. We performed immunohistochemical staining to analyze the expression of TM4SF1 in resected pancreatic tissues and investigated the correlation between TM4SF1 expression and prognosis. The function of TM4SF1 in the invasion and migration of pancreatic cancer cells was analyzed in vitro using an RNA interference technique. In pancreatic cancer tissues, TM4SF1 expression was detected in cancer cells, and patients with high tumor levels of TM4SF1 showed longer survival times than those with low TM4SF1 levels (P=0.0332). In vitro, reduced TM4SF1 expression enhanced the migration (P<0.05) and invasion (P<0.05) of pancreatic cancer cells partially via decreased E-cadherin expression. TM4SF1 protein levels were also reduced after TGF-ß1-induced epithelial-mesenchymal transition (EMT).TM4SF1 expression is associated with better prognosis in pancreatic cancer. Loss of TM4SF1 contributes to the invasion and migration of pancreatic cancer cells.

Peritoneal myofibroblasts at metastatic foci promote dissemination of pancreatic cancer.

Myofibroblasts in the stroma of pancreatic cancers promote tumor proliferation, invasion and metastasis by increasing extracellular matrix and secretion of several growth factors. In contrast, the role of myofibroblasts at peritoneally disseminated sites of pancreatic cancer has not yet been determined. This study was designed to assess the role of myofibroblasts at peritoneally disseminated sites of pancreatic cancer. Three primary cultures of human peritoneal myofibroblasts (hPMFs) were established from disseminated sites of pancreatic cancer and their interactions with the SUIT-2 and CAPAN-1 human pancreatic cancer cell lines were analyzed in vitro. Using a model in BALB/c nu/nu mice, we compared the dissemination ability of intraperitoneally implanted pancreatic cancer cells, with and without hPMFs, and examined the presence of green fluorescent protein (GFP)-labeled hPMFs at peritoneally disseminated sites in mice. hPMFs significantly promoted the migration and invasion of pancreatic cancer cells (P<0.05), while the cancer cells significantly promoted the migration and invasion of hPMFs (P<0.05). In vivo, the number of peritoneally disseminated nodules, more than 3 mm in size, was significantly greater in mice implanted with cancer cells plus hPMFs compared to mice implanted with cancer cells alone, with GFP-labeled hPMFs surviving in the peritoneal cavity of the former. hPMFs promote the peritoneal dissemination of pancreatic cancer. The cancer-stromal cell interaction in the peritoneal cavity may be a new therapeutic target to prevent the dissemination of pancreatic cancer.

Tissue tablet method: an efficient tissue banking procedure applicable to both molecular analysis and frozen tissue microarray.

Frozen human tissues are necessary for research purposes, but tissue banking methods have not changed for more than a decade. Many institutions use cryovial tubes or plastic molds with an optimal cutting temperature compound. However, these methods are associated with several problems, such as samples sticking to one another and the need for a larger storing space. We established an efficient tissue freezing and storing procedure ("tissue tablet method") applicable to both molecular analysis and frozen tissue microarray. Tissue samples were chopped into tiny fragments and embedded into tablet-shaped frozen optimal cutting temperature compound using our original tissue-freezing plate. These tablets can be sectioned and stored in cryovial tubes. We compared the tissue quality of tablet-shaped samples with that of conventional optimal cutting temperature blocks and found no significant difference between them. Tissue microarray is a key method to utilize tissue-banking specimens. However, most tissue microarrays require the coring out of cylindrically shaped tissues from formalin-fixed, paraffin-embedded tissue blocks. Antigenic changes and mRNA degradation are frequently observed with formalin-fixed, paraffin-embedded samples. Therefore, we have applied tablet-shaped samples to construct frozen tissue microarrays with our original mounting base. Constructed tissue microarray sections showed good morphology without obvious artifact and good immunohistochemistry and in situ hybridization results. These results suggest that the quality of arrayed samples was sufficiently appropriate for research purposes. In conclusion, the tissue tablet method and frozen tissue microarray procedure can save time, provides easy tissue handling and processing, and satisfies the demands of research methodologies and tissue banking.

Emerging technologies for telemedicine.

This paper focuses on new technologies that are practically useful for telemedicine. Three representative systems are introduced: a Digital Video Transport System (DVTS), an H.323 compatible videoconferencing system, and Vidyo. Based on some of our experiences, we highlight the advantages and disadvantages of each technology, and point out technologies that are especially targeted at doctors and technicians, so that those interested in using similar technologies can make appropriate choices and achieve their own goals depending on their specific conditions.

Hedgehog signaling pathway is a possible therapeutic target for gastric cancer.

BACKGROUND AND OBJECTIVES: It has been shown that the hedgehog (Hh) signaling pathway is activated in gastric cancer. To investigate the viability of the Hh pathway as a therapeutic target, we analyzed activation of the Hh pathway in gastric cancer. METHODS: Surgically resected gastric carcinoma specimens and lymph nodes were analyzed immunohistochemically. We used the percentage of cancer cells with nuclear translocation of Gli1 as a marker of Hh pathway activation. RESULTS: Nuclear localization of Gli1 was higher in 28 undifferentiated-type tumors than in 30 differentiated-type tumors. Eighteen of the fifty-eight cancer specimens consisted of a mixture of a histologically predominant part and a small area with different histology. In these 18 tumors, the percentage of cells showing nuclear staining of Gli1 was higher in the undifferentiated-type part than in the differentiated-type part. Nuclear staining of Gli1 in primary tumors was positively correlated with lymph node metastasis. The Gli1 nuclear staining percentage of metastatic lymph nodes correlated closely with that of each primary carcinoma. Cyclopamine, a Hh pathway inhibitor, suppressed the growth of gastric cancer cells in vitro. CONCLUSIONS: The Hh pathway may be a useful therapeutic target for such as undifferentiated-type gastric cancer with lymph node metastasis.

Telomerase activity, P53 mutation and Ki-ras codon 12 point mutation of the peripheral blood in patients with hepato pancreato biliary diseases.

BACKGROUND: With progress in molecular biology, the presence of telomerase activity, P53 mutation and Ki-ras codon 12 point mutation has been reported in malignant tumours of the liver, pancreas and biliary tree. The purpose of this paper is to clarify the clinical implications of finding these three biomarkers in the peripheral blood of affected patients. METHODS: Telomerase activity, P53 mutation, and Ki-ras codon 12 point mutation in the peripheral blood were examined among 86 patients with hepato pancreato biliary disease, both benign and malignant, and the results were compared with clinical findings. RESULTS: Of 20 patients with benign conditions, only one patient with intraductal papillary adenoma showing severe dysplasia exhibited a biomarker (telomerase activity) in the peripheral blood. In total, there were 66 patients with various HPB carcinomas. Of 56 cancer patients studied pre-operatively, 16 were positive for more than one biomarker, 13 were positive for telomerase activity, 4 for P53 mutation (three at exon 7 and another at exon 8), and 2 for Kiras codon 12 point mutation (both in the second letter). Twelve of the 16 biomarker-positive patients had stage IV disease as opposed to 23 of 40 biomarker-negative patients. The resectability rate of the cancer was 38% in positive patients and 50% in negative patients. The one-year survival rate after resection was zero in positive patients and 15% in negative patients, but the difference was not significant (P=0.65). Of 32 patients with liver metastasis at the time of the molecular examination, eight were positive and 24 negative. Of 34 patients without liver metastasis, nine were positive and 25 negative. The development of subsequent liver metastases in those without them at the start was not significantly different in those with and without biomarkers (56 vs 36%: P=0.31). CONCLUSIONS: The three novel biomarkers of the peripheral blood seemed to be of little value for screening of early malignant HPB neoplasms but may help to predict liver metastasis.