Prediction of outcomes for high-count monoclonal B lymphocytosis using an epigenetic and immunogenetic signature.

ABSTRACT: Monoclonal B-cell lymphocytosis (MBL) progresses to chronic lymphocytic leukemia (CLL) requiring therapy at 1% to 5% per year. Improved prediction of progression would greatly benefit individuals with MBL. Patients with CLL separate into 3 distinct epigenetic subtypes (epitypes) with high prognostic significance, and recently the intermediate epitype has been shown to be enriched for high-risk immunoglobulin lambda variable (IGLV) 3-21 rearrangements, impacting outcomes for these patients. Here, we employed this combined strategy to generate the epigenetic and light chain immunoglobulin (ELCLV3-21) signature to classify 219 individuals with MBL. The ELCLV3-21 high-risk signature distinguished MBL individuals with a high probability of progression (39.9% and 71.1% at 5 and 10 years, respectively). ELCLV3-21 improved the accuracy of predicting time to therapy for individuals with MBL compared with other established prognostic indicators, including the CLL international prognostic index (c-statistic, 0.767 vs 0.668, respectively). Comparing ELCLV3-21 risk groups in MBL vs a cohort of 226 patients with CLL revealed ELCLV3-21 high-risk individuals with MBL had significantly shorter time to therapy (P = .003) and reduced overall survival (P = .03) compared with ELCLV3-21 low-risk individuals with CLL. These results highlight the power of the ELCLV3-21 approach to identify individuals with a higher likelihood of adverse clinical outcome and may provide a more accurate approach to classify individuals with small B-cell clones.

Japanese Society of Medical Oncology clinical guidelines: Molecular testing for colorectal cancer treatment, 5th edition.

Molecular testing to determine optimal therapies is essential for managing patients with colorectal cancer (CRC). In October 2022, the Japanese Society of Medical Oncology published the 5th edition of the Molecular Testing Guideline for Colorectal Cancer Treatment. In this guideline, in patients with unresectable CRC, RAS/BRAF V600E mutational and mismatch repair tests are strongly recommended prior to first-line chemotherapy to select optimal first- and second-line therapies. In addition, HER2 testing is strongly recommended because the pertuzumab plus trastuzumab combination is insured after fluoropyrimidine, oxaliplatin, and irinotecan in Japan. Circulating tumor DNA (ctDNA)-based RAS testing is also strongly recommended to assess the indications for the readministration of anti-EGFR antibodies. Both tissue- and ctDNA-based comprehensive genomic profiling tests are strongly recommended to assess the indications for targeted molecular drugs, although they are currently insured in patients with disease progression after receiving standard chemotherapy (or in whom disease progression is expected in the near future). Mutational and mismatch repair testing is strongly recommended for patients with resectable CRC, and RAS/BRAF V600E mutation testing is recommended to estimate the risk of recurrence. Mutational and mismatch repair and BRAF testing are also strongly recommended for screening for Lynch syndrome. Circulating tumor DNA-based minimal residual disease (MRD) testing is strongly recommended for estimating the risk of recurrence based on clinical evidence, although MRD testing was not approved in Japan at the time of the publication of this guideline.

Fibroblast inhibition by tocilizumab enabled gemcitabine/nab-paclitaxel rechallenge for pancreatic cancer.

Interleukin-6 (IL-6)/signal transducer and activator of transcription 3 (STAT3) pathway inhibition may overcome chemoresistance of metastatic pancreatic cancer (MPC). We sought to determine the safety and recommended dose of tocilizumab (TCZ), an IL-6 receptor monoclonal antibody, and biological correlates of tumor shrinkage in patients with gemcitabine (GEM)/nanoparticle albumin-bound paclitaxel (nab-PTX)-refractory MPC. This phase 1 study enrolled 10 patients with MPC who had progressed after GEM/nab-PTX. Patients initially received TCZ 8 mg/kg on Day 1 and nab-PTX 100 mg/m2 + GEM 750 mg/m2 on Days 2, 9, and 16. Before and at the end of Cycle 1, biopsy of liver metastases was performed 3-5 h after levofloxacin (LVFX) administration to measure LVFX infiltration into tumor tissue. No dose-limited toxicities occurred, and the recommended dosage of TCZ was determined to be 8 mg/kg. Treatment-emergent adverse events occurred in 80% of patients, of which decreased neutrophil count was the most common. Tumor reduction during Cycle 1 was observed in four patients, who were defined as responders. In paired-biopsy samples, responder-related biological activities were an increase of cleaved PARP expression of tumor nuclei (p = 0.01), a decrease of proliferative cancer-associated fibroblasts (CAFs) (p = 0.08), and an increase of LVFX infiltration in the tumor (p = 0.04). A decrease of phosphorylated STAT3 expression (p = 0.02) favored an increase in LVFX infiltration. In conclusion, TCZ + GEM/nab-PTX-rechallenge had a manageable safety profile and showed preliminary activity via inhibition of CAF and improved intratumoral drug infiltration in MPC.

Preferential B cell differentiation by combined immune checkpoint blockade for renal cell carcinoma is associated with clinical response and autoimmune reactions.

Combined immune checkpoint blockade (ICB) is effective therapy for renal cell carcinoma (RCC). However, the dynamic changes in circulating B cells induced by combined ICB have not been clarified. The present study prospectively examined 22 patients scheduled to receive ICB for unresectable or metastatic RCC between March 2018 and August 2021. Eleven patients received combined therapy with anti-PD-1 (nivolumab) and anti-CTLA-4 (ipilimumab), and the other 11 patients received nivolumab monotherapy. Comprehensive phenotypes of circulating immune cells obtained prior to and after ICB therapy were analyzed by flow cytometry. Although the proportion of naïve B cells among total B cells was significantly decreased, that of switched memory B cells was significantly increased after combined therapy. In responders, the proportion of B cells among peripheral blood mononuclear cells was significantly higher prior to ICB therapy, and the proportion of switched memory B cells among total B cells tended to increase after ICB therapy. Of note, the proportion of plasmablasts among total B cells was significantly increased after ICB therapy in patients who developed severe immune-related adverse events (irAEs), and the proportion of B cells among peripheral blood decreased significantly. Furthermore, in four of five patients who developed immune-related hypophysitis following combined therapy, anti-pituitary antibody was detected in the serum. These results suggested that immune-related hypophysitis was closely related to the increase in circulating plasmablasts. Collectively, this study suggests that combined ICB promotes the differentiation of B cell populations, which is associated with efficient tumor suppression and development of irAEs.

RHAMM marks proliferative subpopulation of human colorectal cancer stem cells.

The cancer stem cell (CSC) theory features typically rare self-renewing subpopulations that reconstitute the heterogeneous tumor. Identification of molecules that characterize the features of CSCs is a key imperative for further understanding tumor heterogeneity and for the development of novel therapeutic strategies. However, the use of conventional markers of CSCs is still insufficient for the isolation of bona fide CSCs. We investigated organoids that are miniature forms of tumor tissues by reconstructing cellular diversity to identify specific markers to characterize CSCs in heterogeneous tumors. Here, we report that the receptor for hyaluronan-mediated motility (RHAMM) expresses in a subpopulation of CD44+ conventional human colorectal CSC fraction. Single-cell transcriptomics of organoids highlighted RHAMM-positive proliferative cells that revealed distinct characteristics among the various cell types. Prospectively isolated RHAMM+CD44+ cells from the human colorectal cancer tissues showed highly proliferative characteristics with a self-renewal ability in comparison with the other cancer cells. Furthermore, inhibition of RHAMM strongly suppressed organoid formation in vitro and inhibited tumor growth in vivo. Our findings suggest that RHAMM is a potential therapeutic target because it is a specific marker of the proliferative subpopulation within the conventional CSC fraction.

Inhibition of insulin-like growth factor-1 receptor enhances eribulin-induced DNA damage in colorectal cancer.

Microtubule targeting agents (MTAs) such as taxanes are broadly used for the treatment of patients with cancer. Although MTAs are not effective for treatment of colorectal cancer (CRC), preclinical studies suggest that a subset of patients with CRC, especially those with cancers harboring the BRAF mutation, could benefit from such agents. However, two MTAs, eribulin (Eri) and vinorelbine, have shown limited clinical efficacy. Here, we report that insulin-like growth factor 1 receptor (IGF-1R) signaling is involved in Eri resistance. Using CRC cell lines, we showed that Eri induces activation and subsequent translocation of IGF-1R to the nucleus. When the activation and/or nuclear translocation of IGF-1R was inhibited, Eri induced DNA damage and enhanced G2 /M arrest. In a xenograft model using the Eri-resistant SW480 cell line, the combination of Eri and the IGF-1R inhibitor linsitinib suppressed tumor growth more efficiently than either single agent. Thus, our results indicated that combination dosing with Eri and an IGF-1R inhibitor could overcome Eri resistance and offer a therapeutic opportunity in CRC.

Potential therapeutic targets discovery by transcriptome analysis of an in vitro human gastric signet ring carcinoma model.

BACKGROUND: Loss of E-cadherin expression is frequently observed in signet ring carcinoma (SRCC). People with germline mutations in CDH1, which encodes E-cadherin, develop diffuse gastric cancer at a higher rate. Loss of E-cadherin expression is thus assumed to trigger oncogenic development. METHODS: To investigate novel therapeutic targets for gastric SRCC, we engineered an E-cadherin-deficient SRCC model in vitro using a human gastric organoid (hGO) with CDH1 knockout (KO). RESULTS: CDH1 KO hGO cells demonstrated distinctive morphological changes similar to SRCC and high cell motility. RNA-sequencing revealed up-regulation of matrix metalloproteinase (MMP) genes in CDH1 KO hGO cells compared to wild type. MMP inhibitors suppressed cell motility of CDH1 KO hGO cells and SRCC cell lines in vitro. Immunofluorescent analysis with 95 clinical gastric cancer tissues revealed that MMP-3 was specifically abundant in E-cadherin-aberrant SRCC. In addition, CXCR4 molecules translocated onto the cell membrane after CDH1 KO. Addition of CXCL12, a ligand of CXCR4, to the culture medium prolonged cell survival of CDH1 KO hGO cells and was abolished by the inhibitor, AMD3100. In clinical SRCC samples, CXCL12-secreting fibroblasts showed marked infiltration into the cancer area. CONCLUSIONS: E-cadherin deficient SRCCs might gain cell motility through upregulation of MMPs. CXCL12-positive cancer-associated fibroblasts could serve to maintain cancer-cell survival as a niche. MMPs and the CXCL12/CXCR4 axis represent promising candidates as novel therapeutic targets for E-cadherin-deficient SRCC.

Spontaneous Regression of Metachronous Intra-Abdominal Desmoid Tumor in a Patient with Familial Adenomatous Polyposis.

Desmoid tumors are clonal fibroblastic neoplasms that arise in soft tissues. Patients with familial adenomatous polyposis (FAP) can develop intra-abdominal desmoid tumors. However, metachronous appearance of intra-abdominal desmoid tumor is rare, and its clinical course is not well known. Here, we report a case of spontaneous regression of metachronous intra-abdominal desmoid tumor in a 36-year-old man with FAP. The patient was diagnosed with FAP and underwent laparoscopic total colorectomy. Intra-abdominal desmoid tumor appeared 2 years later and progressed despite treatment with tamoxifen and sulindac. He received four cycles of combinatory therapy with dacarbazine and adriamycin, resulting in shrinkage and stabilization of the desmoid tumor even after cessation of chemotherapy. A new intra-abdominal desmoid tumor developed 2 years later at a different site from the first lesion and progressed from 65 mm to 70 mm in diameter within a month. The size of the first lesion, however, remained unchanged. We prepared for chemotherapy because the second lesion progressed, but follow-up computed tomography showed spontaneous shrinkage of the second lesion. The patient still has not needed additional therapy as of more than 4 years after the appearance of the second lesion. Immunohistochemical staining showed the presence of macrophages in the second lesion. Although metachronous intra-abdominal desmoid tumor is rare and management protocols have yet to be established, this case suggests that an active surveillance approach may be applicable under careful follow-up in asymptomatic patients.

Macrophages are primed to transdifferentiate into fibroblasts in malignant ascites and pleural effusions.

Cancer-associated fibroblasts (CAFs) play an important role in cancer progression. However, the origin of CAFs remains unclear. This study shows that macrophages in malignant ascites and pleural effusions (cavity fluid-associated macrophages: CAMs) transdifferentiate into fibroblast-like cells. CAMs obtained from gastrointestinal cancer patients were sorted by flow cytometry and cultured in vitro. CD45+CD14+ CAMs transdifferentiated into CD45-CD90+ fibroblast-like cells that exhibited spindle shapes. Then, cDNA microarray analysis showed that the CD45-CD90+ fibroblast-like cells (macrophage-derived CAFs: MDCAFs) had a fibroblast-specific gene expression signature and produced growth factors for epithelial cell proliferation. Human colon cancer cells transplanted into immunodeficient mice with MDCAFs formed larger tumors than cancer cells alone. Gene ontology analyses showed the involvement of TGFß signaling and cell-matrix adhesion in MDCAFs, and transdifferentiation of CAMs into MDCAFs was canceled by inhibiting TGFß and cell adhesion. Furthermore, the acquired genetic alterations in hematopoietic stem cells (HSCs) were shared in CAMs and MDCAFs. Taken together, CAMs could be a source of CAFs and might originate from HSCs. We propose the transdifferentiation process of CAMs into MDCAFs as a new therapeutic target for fibrosis associated with gastrointestinal cancer.

Prominent PD-L1-positive M2 macrophage infiltration in gastric cancer with hyper-progression after anti-PD-1 therapy: A case report.

RATIONALE: Anti-PD-1 antibody is the standard therapy for treatment-resistant gastric cancer, but only a limited number of patients respond. Additionally, cases of hyper-progressive disease (HPD) in which tumor growth accelerates after anti-PD-1 antibody administration have been reported; however, the biological mechanism has not been elucidated. PATIENT CONCERNS: In the present case, metastatic gastric cancer was treated with the anti-PD-1 antibody, nivolumab, as third-line treatment. DIAGNOSIS: After the initiation of nivolumab therapy, a rapidly enlarging para-aortic lymph nodes were observed leading to the diagnosis of HPD. INTERVENTIONS: Multiplex immunohistochemistry was used to examine immune cells infiltrating in the primary tumor and in liver metastasis which were obtained before nivolumab treatment, and in lymph node metastasis which presented with HPD after nivolumab therapy. OUTCOMES: In the primary tumor, helper T (Th) cells, cytotoxic T lymphocytes (CTLs), regulatory T (Treg) cells, and PD-L1-negative macrophages were observed. On the other hand, in metastatic lymph nodes presenting with HPD, PD-L1-positive macrophages prominently increased, while Treg cells, CTLs, and Th cells decreased. PD-L1 expression was not observed in gastric cancer cells among the three specimens. LESSONS: The findings suggest the possibility that PD-L1-positive M2 macrophage might contribute to acceleration of tumor growth with anti-PD-1 therapy in the present case.

Eribulin as a first-line treatment for soft tissue sarcoma patients with contraindications for doxorubicin.

Doxorubicin is a first-line therapy for patients with unresectable advanced soft tissue sarcoma (STS). However, because of cardiotoxicities, it is not used for patients with cardiac problems. Eribulin has exhibited efficacy for advanced STS in second- or later-line treatments. In the present study, we retrospectively analyzed the efficacy and safety of first-line eribulin therapy for patients with advanced STS unable to receive doxorubicin. Six of 28 patients who received eribulin as any line treatment received eribulin as a first-line treatment. The reasons for avoiding doxorubicin were as follows: cardiac problems for four patients and advanced age for two. Median progression-free survival (PFS) of the patients who received eribulin as first-line and, second or later-line therapy were 9.7 months (95% CI: 1.0-not reached) and 3.9 months (95% CI: 2.7-5.9), which were not significantly different. The reasons for discontinuation of eribulin were disease progression and adverse events (2 fatigue and 1 neuropathy) for three patients each. No treatment-related cardiotoxicity was observed. The findings of this study indicated that eribulin exhibits meaningful efficacy for the patients with contraindications for doxorubicin as a first-line treatment without cardiac adverse events. However, appropriate safety management is necessary because older patients are typically among those intolerable of doxorubicin.

Comparative trial of the effects of continuous locomotion training provided at pharmacies: a pilot study.

BACKGROUND: While the world's population is growing older, healthy life expectancy is not increasing. The Japanese Orthopedic Association proposed the concept of 'locomotive syndrome,' manifested as a decline in mobility functions, and introduced a short test battery for assessing the risk of this syndrome. The test battery includes the 'stand-up test,' 'two-step test,' and '25-question Geriatric Locomotive Function Scale' (25-question GLFS). The purpose of locomotion training is to improve and sustain standing and gait functions. However, the place where locomotion training can be provided and followed up has not been decided upon. Therefore, a study was conducted to explore the effect of locomotive syndrome improvement by continuous locomotion training provided at community pharmacies. The objective of this study was to evaluate the effect of pharmacists' instructions and follow-up on the compliance and effectiveness of locomotion training. METHODS: The inclusion criteria were 1) age ≥ 65 years and 2) decline in mobility functions. Guidance on how to perform locomotion training was provided by a pharmacist at the pharmacy. The participants performed locomotion training at home. They were tested and instructed at the pharmacy once a month for 3 months. The main outcome measures were test battery results and the percentage of number of days participants who were able to do the training at home. RESULTS: Eleven participants were analysed. The minimum implementation percentage was 78%. Improvements were observed in 25-question GLFS, muscle strength, and standing time on one leg. Three participants no longer showed a noticeable decline in mobility function. CONCLUSION: Continuous locomotion training provided at pharmacies could contribute to locomotive syndrome prevention. TRIAL REGISTRATION: This study was registered with the University hospital Medical Information Network Clinical Trials Registry (UMIN-CTR; identification No. UMIN000027963 . Registered 28 June 2017).

Thrombocytopenia Caused by Dexamethasone in a Patient with Colorectal Cancer.

Drug-induced immune thrombocytopenia (DITP) is an important cause of thrombocytopenia. A 73-year-old man with relapsed rectal carcinoma received S-1, oxaliplatin and bevacizumab combination therapy (SOX+Bev). Dexamethasone was administered as an antiemetic prophylaxis. On day 2 of the first cycle, thrombocytopenia (8,000/µL) was observed. We sequentially omitted any drugs suspected to possibly induce thrombocytopenia and confirmed dexamethasone as the cause of thrombocytopenia. DITP induced by synthetic corticosteroids is very rare and this is the first case report of DITP induced by dexamethasone. Although rare, DITP due to synthetic corticosteroids including dexamethasone should be a differential diagnosis among patients receiving synthetic corticosteroids with thrombocytopenia.

RNA N6-methyladenosine demethylase FTO regulates PD-L1 expression in colon cancer cells.

Fat mass and obesity-associated protein (FTO) is an enzyme that demethylates N6-methyladenosine (m6A), the most abundant RNA modifications in a cell. The upregulated expression of FTO promotes the progression of various types of cancer by modulating cell-intrinsic genes which relate to malignant potential. However, the impact of FTO on the expression of immune-checkpoint molecules in the tumor cells, which are important for immune escape, has not been well understood. We examined the relevance of FTO to programmed cell death-ligand 1 (PD-L1) expression in colon cancer cells. HCT-116 cells showed high expression of both FTO and PD-L1 proteins. The knockdown of FTO by small interfering RNA decreased mRNA and protein levels of PD-L1 in HCT-116 cells. To elucidate the underlying mechanism by which FTO regulates the expression of PD-L1, we depleted FTO in HCT-116 in the presence of IFN-γ, which is a major stimulus to upregulate PD-L1 expression. Depletion of FTO reduced PD-L1 expression in an IFN-γ signaling-independent manner. RNA immunoprecipitation assay revealed the m6A modification of the PD-L1 mRNA and the binding of FTO to the PD-L1 mRNA in HCT-116. Taken together, our results indicated that FTO could regulate PD-L1 expression in colon cancer cells and provides new insights into the regulation of PD-L1 expression by RNA modification.

Helper T cell-dominant tertiary lymphoid structures are associated with disease relapse of advanced colorectal cancer.

Tertiary lymphoid structures (TLSs), clusters of immune cells found around tumor tissue, have been shown to be associated with anti-tumor immunity, but the cellular composition within each TLS and whether the cellular composition of a TLS affects a patient's prognosis are poorly understood. In the present study, each TLS was categorized according to its cellular composition determined by a system of multiplex immunohistochemical staining and quantitative analysis, and the correlation between the category and prognosis was examined. Sixty-seven patients with curatively resected stage II/III colorectal cancer (CRC) were enrolled. A TLS, consisting of germinal center B cells, follicular dendritic cells, T helper (Th) cells, B cells, cytotoxic T cells, and macrophages, was confirmed in the tumor tissue of 58 patients (87%). The densities of Th cells and macrophages were significantly higher in relapsed patients than in not-relapsed patients (p = .043 and p = .0076). A higher ratio of Th cells was the most significant independent risk factor for disease relapse on multivariate analysis. The subset increasing in Th cells was GATA3+ Th2. A total of 353 TLSs was divided into five clusters according to immune cell composition. Among them, the Th-rich type TLS was significantly increased (p = .0009) in relapsed patients. These data suggest the possibility that Th cell-dominant composition might disturb the anti-tumor immune response, and the function of each TLS might differ depending on its composition.

OX40 and LAG3 are associated with better prognosis in advanced gastric cancer patients treated with anti-programmed death-1 antibody.

BACKGROUND: Anti-PD-1 monoclonal antibody, nivolumab, has shown efficacy for advanced gastric cancer (AGC). However, the specific immune cell subsets predominantly activated during the period of anti-PD-1 therapy for AGC have not been clarified. METHODS: Peripheral blood of 30 AGC patients treated with nivolumab was prospectively obtained before the initial and second administrations and at the time of progressive disease (PD). The proportions of immune cell subsets and the serum concentrations of cytokines were systematically analysed by flow cytometry. Associations of subsets and serum cytokines with therapeutic effects were evaluated. RESULTS: After the initial administration, significant increases in activated central/effector memory, activated effector T cells, and activated T-helper 1 subsets were observed. At the time of PD, activated regulatory T cells, LAG3-positive CD4+/CD8+ T cells, and TIM3-positive CD4+/CD8+ T cells increased significantly. Significant positive correlations were shown between progression-free survival and proportions of LAG3-positive CD4+/CD8+ T cells and of OX40-positive CD4+/CD8+ T cells (log-rank p = 0.0008, 0.0003, 0.0035 and 0.0040). CONCLUSIONS: Nivolumab therapy enhances activation of central/effector memory and effector subsets of CD4+/CD8+ T cells. The expression levels of LAG-3 and OX40 on T cells correlated with the efficacy of nivolumab therapy and could be reasonable biomarkers for anti-PD-1 therapy.

Patterns of paternal investment predict cross-cultural variation in jealous response.

Long-lasting, romantic partnerships are a universal feature of human societies, but almost as ubiquitous is the risk of instability when one partner strays. Jealous response to the threat of infidelity is well studied, but most empirical work on the topic has focused on a proposed sex difference in the type of jealousy (sexual or emotional) that men and women find most upsetting, rather than on how jealous response varies1,2. This stems in part from the predominance of studies using student samples from industrialized populations, which represent a relatively homogenous group in terms of age, life history stage and social norms3,4. To better understand variation in jealous response, we conducted a 2-part study in 11 populations (1,048 individuals). In line with previous work, we find a robust sex difference in the classic forced-choice jealousy task. However, we also show substantial variation in jealous response across populations. Using parental investment theory, we derived several predictions about what might trigger such variation. We find that greater paternal investment and lower frequency of extramarital sex are associated with more severe jealous response. Thus, partner jealousy appears to be a facultative response, reflective of the variable risks and costs of men's investment across societies.

Methylation of drug resistance-related genes in chemotherapy-sensitive Epstein-Barr virus-associated gastric cancer.

Epstein-Barr virus (EBV)-associated gastric cancer (GC) is associated with a high degree of DNA methylation. However, the association between chemotherapy susceptibility and tumor DNA methylation in advanced diseases remains unclear. The comprehensive DNA methylation status of GC cells obtained from an advanced EBV-associated GC (EBVGC) case, in which complete response to S-1 plus cisplatin chemotherapy was achieved, was analyzed using a DNA methylation microarray. We compared DNA methylation of GC cells with public data and identified genes with higher methylation in EBVGC cell lines than in normal gastric cells, and genes in which methylation was increased by EBV. Of these genes, ABCG2, AHNAK2, BCL2, FZD1, and TP73 are associated with published evidence for resistance to 5-fluorouracil and cisplatin. Silencing of these genes may be associated with hypersensitivity to chemotherapy.

PD-1+ TIM-3+ T cells in malignant ascites predict prognosis of gastrointestinal cancer.

The liquid biopsy of ascites fluid could be an excellent source of tumor and microenvironment for the study of prognostic biomarkers because of its accessibility. Tumor-infiltrating lymphocytes (TILs) can predict prognosis in multiple malignancies, including the response to immune checkpoint inhibitors, a breakthrough cancer therapy. However, TILs' profiles from malignant ascites have not been extensively studied. Using flow cytometric analysis, we quantified the proportion of exhausted T cells and memory/naive/effector T-cell subsets, among the CD4+ and CD8+ T-cell populations of paired TILs and peripheral blood T cell samples (n = 22). The correlation between CD4+ and CD8+ subset profiles suggested that the combined analysis of CD4+ and CD8+ cells in malignant ascites was clinically significant. We found that cells positive for the exhaustion markers programmed cell death-1 (PD-1), and T-cell immunoglobulin and mucin domain 3 (TIM-3), and cells coexpressing PD-1 and TIM-3 abundantly exist among malignant ascites TILs. Furthermore, patients with high frequency of PD-1+ TIM-3+ cells among the CD4+ and CD8+ T-cell population showed worse clinical outcome in multivariate analysis (n = 27). We propose that exhausted ascites TILs represent a clinically significant prognostic biomarker in advanced gastrointestinal cancer and represent an important target for immune checkpoint inhibitors.

Epithelial-mesenchymal transition is activated in CD44-positive malignant ascites tumor cells of gastrointestinal cancer.

Disseminated cancer cells in malignant ascites possess unique properties that differ from primary tumors. However, the biological features of ascites tumor cells (ATC) have not been fully investigated. By analyzing ascites fluid from 65 gastrointestinal cancer patients, the distinguishing characteristics of ATC were identified. High frequency of CD44+ cells was observed in ATC using flow cytometry (n = 48). Multiplex quantitative PCR (n = 15) showed higher gene expression of epithelial-mesenchymal transition (EMT)-related genes and transforming growth factor beta (TGF-beta)-related genes in ATC than in the primary tissues. Immunohistochemistry (n = 10) showed that ATC also had much higher expression of phosphorylated SMAD2 than that in the corresponding primary tissues. TGF-beta 1 was detected in all cases of malignant ascites by enzyme-linked immunoassay (n = 38), suggesting the possible interaction of ATC and the ascites microenvironment. In vitro experiments revealed that these ATC properties were maintained by TGF-beta 1 in cultured ATC(n = 3). Here, we showed that ATCrevealed high frequencies of CD44 and possessed distinct EMT features from primary tissues that were mainly maintained by TGF-beta 1 in the ascites.