IMMUNOREACT 7: Regular aspirin use is associated with immune surveillance activation in colorectal cancer.

BACKGROUND: Long-term daily use of aspirin reduces incidence and mortality due to colorectal cancer (CRC). This study aimed to analyze the effect of aspirin on the tumor microenvironment, systemic immunity, and on the healthy mucosa surrounding cancer. METHODS: Patients with a diagnosis of CRC operated on from 2015 to 2019 were retrospectively analyzed (METACCRE cohort). Expression of mRNA of immune surveillance-related genes (PD-L1, CD80, CD86, HLA I, and HLA II) in CRC primary cells treated with aspirin were extracted from Gene Expression Omnibus-deposited public database (GSE76583). The experiment was replicated in cell lines. The mucosal immune microenvironment of a subgroup of patients participating in the IMMUNOREACT1 (ClinicalTrials.gov NCT04915326) project was analyzed with immunohistochemistry and flow cytometry. RESULTS: In the METACCRE Cohort, 12% of 238 patients analyzed were aspirin users. Nodal metastasis was significantly less frequent (p = .008) and tumor-infiltrating lymphocyte infiltration was higher (p = .02) among aspirin users. In the CRC primary cells and selected cell lines, CD80 mRNA expression was increased following aspirin treatment (p = .001). In the healthy mucosa surrounding rectal cancer, the ratio of CD8/CD3 and epithelial cells expressing CD80 was higher in aspirin users (p = .027 and p = .034, respectively). CONCLUSIONS: These data suggested that regular aspirin use may have an active role in enhancing immunosurveillance against CRC.

Innate Immunity Activation in Newly Diagnosed Ileocolonic Crohn's Disease: A Cohort Study.

BACKGROUND: Recent studies showed that early surgery for Crohn's disease leads to a lower recurrence rate. However, the underlying mechanism is unknown. OBJECTIVE: The study aims to analyze the innate immunity microenvironment in ileal mucosa according to the duration of Crohn's disease. DESIGN: A prospective cohort study. SETTINGS: Tertiary referral center for IBD surgery. PATIENTS: A total of 88 consecutive patients with Crohn's disease undergoing ileocolonic resection were prospectively enrolled. Mucosal samples were obtained from both healthy and inflamed ileum. Data from a public data set were analyzed as an external validation cohort. MAIN OUTCOME MEASURES: Neutrophil infiltration was evaluated by histological asessment and macrophage subpopulation was assessed by immunohistochemistry. Expressions of TLR2 , TLR4 , TLR5 , DEFB1 , DEFB4A , DEFB103 , DEFA5 , and DEFA6 were quantified by real-time quantitative polymerase chain reaction. Concentrations of BDNF, CCL-11, ICAM-1, IL-1A, IL-1ß, IL-1RN, IL-12p40, IL-12p70, IL-15, IL-17A, IL-23A, MMP-3, CCL-3, KITLG, and VEGFA were determined with an immunometric assay. RESULTS: Neutrophil infiltration is inversely correlated with disease duration. DEFB4A mRNA expression tended to be higher in late-stage Crohn's disease ( p = 0.07). A higher number of macrophages expressed CD163 at low intensity in late-stage Crohn's disease ( p = 0.04). The concentration of IL-15 ( p = 0.02) and IL-23A ( p = 0.05) was higher in healthy ileal mucosa of early-stage patients. In the external cohort, expressions of DEFB1 ( p = 0.03), DEFB4A ( p = 0.01), IL-2 ( p = 0.04), and IL-3 ( p = 0.03) increased in patients with late-stage Crohn's disease. LIMITATIONS: A relatively small number of patients, especially in the newly diagnosed group. CONCLUSIONS: In newly diagnosed Crohn's disease, high levels of IL-15 and IL-23 in healthy mucosa suggest that innate immunity is the starter of acute inflammation. Moreover, M2 macrophages increase in the healthy mucosa of patients with late-stage Crohn's disease, suggesting that reparative and profibrotic processes are predominant in the long term, and in this phase, anti-inflammatory therapy may be less efficient. See Video Abstract . ACTIVACIN DE LA INMUNIDAD INNATA EN LA RECIENTEMENTE DIAGNOSTICADA ENFERMEDAD DE CROHN ILEOCLICA UN ESTUDIO DE COHORTE: ANTECEDENTES:Estudios recientes demostraron que la cirugía temprana para la enfermedad de Crohn (EC) conduce a una menor tasa de recurrencia. Sin embargo, se desconoce el mecanismo subyacente.OBJETIVO:El estudio tiene como objetivo analizar el microambiente de la inmunidad innata en la mucosa ileal según la duración de la EC.DISEÑO:Un estudio de cohorte prospectivo.AJUSTES:Centro terciario de referencia para cirugía de EII.PACIENTES:Fueron registrados de manera prospectiva y consecutiva 88 pacientes con EC sometidos a resección ileocolónica. Se obtuvieron muestras de mucosa ileal, tanto del íleon sano como del íleon inflamado. Los datos se analizaron como una cohorte de validación externa.PRINCIPALES MEDIDAS DE RESULTADO:Fueron evaluados la infiltración de neutrófilos por histología y la subpoblación de macrófagos por inmunohistoquímica. La expresión de TLR2, TLR4, TLR5, DEFB1, DEFB4A, DEFB103, DEFA5 y DEFA6 fueron cuantificados mediante qPCR en tiempo real. Las concentraciones de BDNF, CCL-11, ICAM-1, IL-1A, IL-1B, IL-1RN, IL-12 p40, IL-12 p70, IL-15, IL-17A, IL-23A, MMP-3, CCL-3, KITLG, VEGFA se determinaron con ensayo inmunométrico.RESULTADOS:La infiltración de neutrófilos se correlaciona inversamente con la duración de la enfermedad. La expresión del ARNm de DEFB4A mostro una tendencia a ser mayor en la EC en etapa tardía ( p = 0,07). Un mayor número de macrófagos expresaron CD163 a baja intensidad en la etapa tardía ( p = 0,04). La concentración de IL15 ( p = 0,02) e IL23A ( p = 0,05) fue mayor en la mucosa ileal sana de pacientes en estadio temprano. En la cohorte externa, la expresión de DEFB1 ( p = 0,03) y DEFB4A ( p = 0,01), IL2 ( p = 0,04) e IL3 ( p = 0,03) aumentó en pacientes en etapa tardía.LIMITACIONES:Un número relativamente pequeño de pacientes, especialmente en el grupo recién diagnosticado.CONCLUSIONES:En la EC recién diagnosticada, los altos niveles de IL-15 e IL-23 en la mucosa sana sugieren que la inmunidad innata es el promotor de la inflamación aguda. Además, los macrófagos M2 aumentan en la mucosa sana de pacientes con EC en etapa tardía, lo que sugiere que los procesos reparadores y profibróticos son predominantes a largo plazo y en esta fase, la terapia antiinflamatoria puede ser menos eficiente. (Traducción-Dr. Osvaldo Gauto ).

IMMUNOREACT 6: weak immune surveillance characterizes early-onset rectal cancer.

BACKGROUND: Colon cancer in young patients is often associated with hereditary syndromes; however, in early-onset rectal cancer, mutations of these genes are rarely observed. The aim of this study was to analyse the features of the local immune microenvironment and the mutational pattern in early-onset rectal cancer. METHODS: Commonly mutated genes were analysed within a rectal cancer series from the University Hospital of Padova. Mutation frequency and immune gene expression in a cohort from The Cancer Genome Atlas ('TCGA') were compared and immune-cell infiltration levels in the healthy rectal mucosa adjacent to rectal cancers were evaluated in the IMMUNOlogical microenvironment in REctal AdenoCarcinoma Treatment 1 and 2 ('IMMUNOREACT') series. RESULTS: In the authors' series, the mutation frequency of BRAF, KRAS, and NRAS, as well as microsatellite instability frequency, were not different between early- and late-onset rectal cancer. In The Cancer Genome Atlas series, among the genes with the most considerable difference in mutation frequency between young and older patients, seven genes are involved in the immune response and CD69, CD3, and CD8ß expression was lower in early-onset rectal cancer. In the IMMUNOlogical microenvironment in REctal AdenoCarcinoma Treatment 1 and 2 series, young patients had a lower rate of CD4+ T cells, but higher T regulator infiltration in the rectal mucosa. CONCLUSION: Early-onset rectal cancer is rarely associated with common hereditary syndromes. The tumour microenvironment is characterized by a high frequency of mutations impairing the local immune surveillance mechanisms and low expression of immune editing-related genes. A constitutively low number of CD4 T cells associated with a high number of T regulators indicates an imbalance in the immune surveillance mechanisms.

IMMUNOREACT 5: female patients with rectal cancer have better immune editing mechanisms than male patients - a cohort study.

BACKGROUND: Studies evaluating sex differences in colorectal cancer (CRC) tumor microenvironment are limited, and no previous study has focused on rectal cancer patients' constitutive immune surveillance mechanisms. The authors aimed to assess gender-related differences in the immune microenvironment of rectal cancer patients. METHODS: A systematic review and meta-analysis were conducted up to 31 May 2021, including studies focusing on gender-related differences in the CRC tumor microenvironment. Data on the mutational profile of rectal cancer were extracted from the Cancer Genome Atlas (TCGA). A subanalysis of the two IMMUNOREACT trials (NCT04915326 and NCT04917263) was performed, aiming to detect gender-related differences in the immune microenvironment of the healthy mucosa in patients with early (IMMUNOREACT 1 cohort) and locally advanced rectal cancer following neoadjuvant therapy (IMMUNOREACT 2 cohort). In the retrospective IMMUNOREACT 1 cohort (therapy naive), the authors enrolled 442 patients (177 female and 265 male), while in the retrospective IMMUNOREACT 2 cohort (patients who had neoadjuvant therapy), we enrolled 264 patients (80 female and 184 male). In the prospective IMMUNOREACT 1 cohort (therapy naive), the authors enrolled 72 patients (26 female and 46 male), while in the prospective IMMUNOREACT 2 cohort (patients who had neoadjuvant therapy), the authors enrolled 105 patients (42 female and 63 male). RESULTS: Seven studies reported PD-L1 expression in the CRC microenvironment, but no significant difference could be identified between the sexes. In the TGCA series, mutations of SYNE1 and RYR2 were significantly more frequent in male patients with rectal cancer. In the IMMUNOREACT 1 cohort, male patients had a higher expression of epithelial cells expressing HLA class I, while female patients had a higher number of activated CD4+Th1 cells. Female patients in the IMMUNOREACT 2 cohort showed a higher infiltration of epithelial cells expressing CD86 and activated cytotoxic T cells (P=0.01). CONCLUSIONS: Male patients have more frequent oncogene mutations associated with a lower expression of T-cell activation genes. In the healthy mucosa of female patients, more Th1 cells and cytotoxic T cells suggest a potentially better immune response to the tumor. Sex should be considered when defining the treatment strategy for rectal cancer patients or designing prognostic scores.

Tumor immune microenvironment in therapy-naive esophageal adenocarcinoma could predict the nodal status.

BACKGROUND: Currently, preoperative staging of esophageal adenocarcinoma (EAC) has modest reliability and accuracy for pT and pN stages prediction, which heavily affects overall survival. The interplay among immune checkpoints, oncogenes, and intratumoral and peritumoral immune infiltrating cells could be used to predict loco-regional metastatic disease in early EAC. METHODS: We prospectively evaluated immune markers expression and oncogenes status as well as intratumoral and peritumoral immune infiltrating cells populations in esophageal mucosa samples obtained from neoadjuvant therapy-naïve patients who had esophagectomy for EAC. RESULTS: Vascular invasion and high infiltration of lamina propria mononuclear cells resulted associated with nodal metastasis. Low infiltration of activated CD8+ CD28+ T cells was observed in both intratumoral and peritumoral mucosa of patients with nodal metastasis. Low levels of CD69, MYD88, and TLR4 transcripts were detected in the intratumoral specimen of patients with lymph node involvement. Receiver operating characteristic curve analysis showed good accuracy for detecting nodal metastasis for all the markers tested. Significant lower infiltration of CD8 T cells and M1 macrophages and a lower expression of CD8A, CD8B, and TBX21 were found also in Esophageal Adenocarcinoma TCGA panCancer Atlas in the normal tissue of patients with nodal metastasis. CONCLUSIONS: Our data suggest that immune surveillance failure is the main driver of nodal metastasis onset. Moreover, nodal metastasis containment also involves the immune microenvironment of the peritumoral healthy tissue.

Metachronous colorectal cancer have a similar microsatellite instability frequency but a lower infiltration of lymphomononuclear cells than primary lesions.

BACKGROUND: An increased risk of metachronous colorectal cancer is usually associated with microsatellite instability occurring in Lynch syndrome. However, not all patients with metachronous colorectal cancer have microsatellite instability. The density of tumor-infiltrating lymphocytes is an independent predictor of outcome in patients with colorectal cancer, and a fascinating hypothesis is that they can be involved in the onset of metachronous colorectal cancer. The aim of this study was to analyze the tumor microenvironment and tumor mutation frequency in sporadic and metachronous colorectal cancer. METHODS: The clinical and pathological records of a series of consecutive colorectal cancer patients who were operated on from 2015 to 2019 were retrieved for this retrospective study. We defined metachronous colorectal cancer as a second colorectal cancer that appeared at least 1 year after the primary one, and sporadic colorectal cancer as those that did not have a metachronous colorectal cancer. Histology for the infiltration of intratumoral lymphomononuclear cells, immunohistochemistry for MLH1, PMS2, MSH2, and MSH6, and mutational analysis of BRAF, KRAS, and NRAS were all performed. Sporadic colorectal cancer and metachronous colorectal cancer were compared. Nonparametric tests were used for small sample size comparison. RESULTS: In the study, 238 patients were operated on for colorectal cancer at the General Surgery Unit of the Azienda Ospedaliera di Padova from 2015 to 2019. We identified 26 patients with metachronous colorectal cancer, and only 3 of them had had adjuvant therapy after the primary colorectal cancer. No difference was observed in terms of cancer stage between metachronous and sporadic colorectal cancer. Mismatch repair gene deficiencies and microsatellite instability frequency was similar in metachronous colorectal cancer and in sporadic colorectal cancer (P = .77). Likewise, the mutation frequency of BRAF and KRAs was similar in the 2 groups (P = .75 and P = .21, respectively). To the contrary, the absence of infiltration of lymphomononuclear cells within the tumor (P = .004) in patients with metachronous colorectal cancer was more frequent and they tended to have a higher frequency of NRAS mutation (P = .06). CONCLUSION: Our study showed that, rather unexpectedly, microsatellite instability frequency was similar in metachronous and sporadic colorectal cancer. Moreover, our data suggest that an altered immune microenvironment may be a crucial factor, permitting the occurrence of metachronous colorectal cancer. In fact, the absence of lymphomononuclear cells can be the substrate for a weak immune response to cancer neoantigens, opening the way to a second primary colorectal cancer.

Persistent Herpes Simplex Virus Type 1 Infection of Enteric Neurons Triggers CD8+ T Cell Response and Gastrointestinal Neuromuscular Dysfunction.

Behind the central nervous system, neurotropic viruses can reach and persist even in the enteric nervous system (ENS), the neuronal network embedded in the gut wall. We recently reported that immediately following orogastric (OG) administration, Herpes simplex virus (HSV)-1 infects murine enteric neurons and recruits mononuclear cells in the myenteric plexus. In the current work, we took those findings a step forward by investigating the persistence of HSV-1 in the ENS and the local adaptive immune responses against HSV-1 that might contribute to neuronal damage in an animal model. Our study demonstrated specific viral RNA transcripts and proteins in the longitudinal muscle layer containing the myenteric plexus (LMMP) up to 10 weeks post HSV-1 infection. CD3+CD8+INFγ+ lymphocytes skewed towards HSV-1 antigens infiltrated the myenteric ganglia starting from the 6th week of infection and persist up to 10 weeks post-OG HSV-1 inoculation. CD3+CD8+ cells isolated from the LMMP of the infected mice recognized HSV-1 antigens expressed by infected enteric neurons. In vivo, infiltrating activated lymphocytes were involved in controlling viral replication and intestinal neuromuscular dysfunction. Indeed, by depleting the CD8+ cells by administering specific monoclonal antibody we observed a partial amelioration of intestinal dysmotility in HSV-1 infected mice but increased expression of viral genes. Our findings demonstrate that HSV-1 persistently infects enteric neurons that in turn express viral antigens, leading them to recruit activated CD3+CD8+ lymphocytes. The T-cell responses toward HSV-1 antigens persistently expressed in enteric neurons can alter the integrity of the ENS predisposing to neuromuscular dysfunction.

MLH1 Deficiency Down-Regulates TLR4 Expression in Sporadic Colorectal Cancer.

Patients with mismatch repair (MMR)-deficient colorectal cancer (CRC) have a more favorable prognosis than patients with tumors with intact MMR. In order to obtain further insights on the reasons for this different outcome, we investigated the interplay between MMR genes and TLR4/MyD88 signaling. The cancer genome atlas (TCGA) databases were selected to predict the differential expression of TLR4 in colon cancer and its correlation with MMR genes. Moreover, the expression of MMR genes and TLR4 was evaluated by immunohistochemistry in 113 CRC samples and a cohort of 63 patients was used to assess TLR4 mRNA expression and MLH1 epigenetic silencing status. In vitro, the effect of MLH1 knockdown on TLR4 expression was quantified by Real Time PCR. TLR4 expression resulted dependent on MMR status and directly correlated to MLH1 expression. In vitro, MLH1 silencing decreased TLR4 expression. These observations may reflect the better prognosis and the chemoresistance of patients with CRC and MMR defects.

Fistula-Related Cancer in Crohn's Disease: A Systematic Review.

Perianal fistulizing Crohn's disease is a very disabling condition with poor quality of life. Patients with perianal fistulizing Crohn's disease are also at risk of perianal fistula-related squamous cell carcinoma (SCC). Cancer arising at the site of a chronic perianal fistula is rare in patients with Crohn's disease and there is a paucity of data regarding its incidence, diagnosis and management. A systematic review of the literature was undertaken using Medline, Embase, Pubmed, Cochrane and Web of Science. Several small series have described sporadic cases with perianal cancer in Crohn's disease. The incidence rate of SCC related to perianal fistula was very low (<1%). Prognosis was poor. Colorectal disease, chronic perianal disease and HPV infection were possible risk factors. Fistula-related carcinoma in CD (Chron's disease) can be very difficult to diagnose. Examination may be limited by pain, strictures and induration of the perianal tissues. HPV is an important risk factor with a particular carcinogenesis mechanism. MRI can help clinicians in diagnosis. Examination under anesthesia is highly recommended when findings, a change in symptoms, or simply long-standing disease in the perineum are present. Future studies are needed to understand the role of HPV vaccination in preventing fistula-related cancer.

Esophageal squamous cell carcinoma metachronous to head and neck cancers.

BACKGROUND: In some HNSCC patients, a metachronous ESCC may develop. No information is available on the HNSCC-associated ESCCs microenvironment and etiology. METHODS: Among 134 ESCCs surgically treated between 2009 and 2015, a series of 6 HNSCC-associated ESCCs was collected. A series of 12 sex-, age- and stage-matched ESCCs with no previous oncological medical history was selected for comparison. Histologic assessment of intratumoral inflammatory infiltration and immunohistochemistry for CD4, CD8, CD80, PD1, PD-L1 and p53 were performed. HPV detection/genotyping was assessed by PCR single step and reverse line blot. RESULTS: HPV DNA was negative in all the HNSCC-associated ESCCs. In comparison to non-HNSCC-associated carcinomas, the 6 cases presented a lower lymphomonocytic infiltration, which also corresponded to a lower prevalence of CD4 + T cell infiltration and, 5/6 cases presented a PD-L1 CPS ≥ 1. All the HNSCC-associated ESCCs resulted positive for p53 immunostaining in ≥50 % of cancer cells. CONCLUSION: Our study suggests that HPV infection is not an etiological factor associated to ESCC after HNSCC. On the other hand, p53 overexpression is a common finding. Moreover, our data suggest that an altered immune microenvironment, conditioned by a dysregulation in lymphomonocytic infiltration, may be a crucial factor allowing the occurrence of a metachronous ESCC.

Can Vascular Endothelial Growth Factors and CD34 Expression Implement NICE (Narrow-Band Imaging International Colorectal Endoscopic) Classification in Colorectal Polypoid Lesion Diagnosis?

BACKGROUND: Vascular endothelial growth factor (VEGF) is a subfamily of growth factors involved in angiogenesis; CD34+ cells are normally found in endothelial progenitor cells and endothelial cells of blood vessels. Colonic adenomatous polyps may not always be completely removable endoscopically, and a preoperative diagnosis might still be necessary. The aim of the study was to evaluate whether VEGF-A, VEGF-C and CD34 mRNA expression along colorectal carcinogenesis steps can implement NICE (Narrow-Band Imaging International Colorectal Endoscopic) classification in the diagnosis of malignancy in colorectal polypoid lesions. METHODS: Seventy-one subjects with colonic adenoma or cancer who underwent screening narrow-band imaging (NBI) colonoscopy were prospectively enrolled in the MICCE1 project (Treviso center). Polyps were classified according to the NICE classification. Real-time RT-PCR for VEGF-A, VEGF-C and CD34 mRNA expression was performed. Nonparametric statistics, receiver-operating characteristic curve analysis and logistic multiple regression analysis were used. RESULTS: VEGF-A and CD34 mRNA expression was significantly higher in sessile adenomas than in polypoid ones (p < 0.001 and p = 0.01, respectively). VEGF-A, VEGF-C and CD34 mRNA expression was significantly higher in adenocarcinoma than in adenoma (p = 0.01, p = 0.01 and p = 0.01, respectively). The accuracy of VEGF-A, VEGF-C and CD34 mRNA expression for prediction of malignancy was 0.79 (95% CI 0.65-0.90), 0.81 (95% CI 0.66-0.91) and 0.80 (95% CI 0.65-0.90), respectively, while the accuracy of the NICE classification was 0.85 (95% CI 0.72-0.94). The determination coefficient R2, which indicates the amount of the variability explained by a regression model, for NICE classification alone was 0.24 (p < 0.001). A regression model that included NICE classification and VEGF-C mRNA expression showed an R2 = 0.39 as well as a model including NICE classification and CD34 mRNA levels. CONCLUSIONS: This study demonstrated that VEGF-C and CD34 mRNA levels might be useful to stratify colorectal polyps in different risk of progression classes by implementing the accuracy of the NICE classification. Studies on in vivo detection of these markers are warranted.

Immune surveillance activation after neoadjuvant therapy for esophageal adenocarcinoma and complete response.

After neoadjuvant chemoradiotherapy for esophageal adenocarcinoma, up to 29% of patients have a pathological complete response (pCR). What to do afterward is still under debate. The aim of this prospective study was to define which local markers of immune response might act as predictors of pCR and of recurrence after pCR. The peritumoral healthy mucosa of the surgical specimen was sampled at esophagectomy and analyzed by immunohistochemistry, flow cytometry and Real-Time PCR. One hundred and twenty-three patients received neoadjuvant therapy for esophageal adenocarcinoma and were included in the study. Significantly higher rate of natural killer (NK) cells (CD57+), intraepithelial CD8 + T lymphocytes and degranulating T- and NK-cells (CD107+) were observed in the healthy mucosa of patients with pCR. Moreover, pCR was characterized by a lower immune-check points gene expression level. T-cell activation markers mRNA levels were significantly lower in patients with pCR and recurrent disease, showing an excellent accuracy in the prediction of the postoperative recurrence. Costimulatory molecules mRNA relative levels tended to be lower in patients with pCR and recurrent disease, showing a good accuracy in the prediction of postoperative recurrence in patients with pCR. The immune profile identified in this study might further be tested in large prospective trials as marker of pCR after neoadjuvant therapy and as predictor of recurrence after pCR.

The Pathologic and Molecular Landscape of Esophageal Squamous Cell Carcinogenesis.

Esophageal squamous cell carcinoma represents the most common histotype of epithelial neoplasm occurring within esophageal mucosa worldwide. Despite the comprehensive molecular characterization of this entity, to date no significant targeted therapy has been introduced into clinical practice. In this review, we describe the molecular landscape of esophageal squamous cell carcinoma based on the most recent literature. Moreover, we focus on other rare variants and on the relationship with head and neck squamous cell carcinomas.

Reactive Oxygen Species and Antitumor Immunity-From Surveillance to Evasion.

The immune system is a crucial regulator of tumor biology with the capacity to support or inhibit cancer development, growth, invasion and metastasis. Emerging evidence show that reactive oxygen species (ROS) are not only mediators of oxidative stress but also players of immune regulation in tumor development. This review intends to discuss the mechanism by which ROS can affect the anti-tumor immune response, with particular emphasis on their role on cancer antigenicity, immunogenicity and shaping of the tumor immune microenvironment. Given the complex role that ROS play in the dynamics of cancer-immune cell interaction, further investigation is needed for the development of effective strategies combining ROS manipulation and immunotherapies for cancer treatment.

Interferon-Gamma and Tumor Necrosis Factor-Related Weak Inducer of Apoptosis Expression in Neoangiogenesis in Colorectal Polypoid Lesions.

BACKGROUND: Interferon gamma (IFNγ) and tumor necrosis factor-related weak inducer of apoptosis (TWEAK) molecules seem to have a potential effect on angiogenic factors such as vascular endothelial growth factor (VEGF). The aim of this study was to assess a possible interplay between IFNγ and TWEAK cytokines and VEGF machinery in the different steps of colorectal carcinogenesis. METHODS: A total of 92 subjects with colonic adenoma or cancer who underwent screening colonoscopy or surgery were prospectively enrolled. Polypoid lesion tissue samples were collected and frozen. Real-time reverse transcription polymerase chain reaction for IFNγ, TWEAK, and VEGF-A mRNA expression was performed. Immunoassays for VEGF-A, VEGF-C, VEGFR-1, VEGFR-2, and VEGFR-3 were also performed. Nonparametric statistics, receiver operating characteristic curve analysis, and logistic multiple regression analysis were used. RESULTS: IFNγ and TWEAK mRNA expression was higher in patients with T2 or more advanced colorectal cancer than in those with adenomas or T1 cancer (p < 0.001 and p = 0.01, respectively). IFNγ and TWEAK mRNA expression levels directly correlated with VEGF-A mRNA expression levels (rho = 0.44, p < 0.001 and rho = 0.29, p = 0.004, respectively). On the contrary, IFNγ and TWEAK mRNA expression levels inversely correlated with VEGF-C protein levels (rho = -0.29, p = 0.04 and rho = -0.31, p = 0.03, respectively). Similarly, IFNγ and TWEAK mRNA expression levels inversely correlated with VEGFR2 protein levels (rho = -0.38, p = 0.033 and rho = -0.40, p = 0.025, respectively). CONCLUSION: This study showed that in colorectal polypoid lesions, IFNγ and TWEAK expressions are directly correlated to VEGF-A expression but inversely correlated with VEGFR2 levels, suggesting a possible feedback mechanism in the regulation of VEGF-A expression.

CD80 expression promotes immune surveillance in Barrett's metaplasia.

Esophageal adenocarcinoma (EAC) is the final step of a pathway starting with esophageal reflux disease, Barrett's metaplasia and Barrett's dysplasia. Positive costimulatory ligands such as CD80 have been suggested to contribute to anti-tumor T-cell efficacy. Here we report for the first time the role of CD80 in the inflammatory esophageal carcinogenesis and characterize the immune environment of EAC. Mucosa samples from cancer were obtained during esophagectomy from patients affected by EAC. Fresh biopsies were obtained from patients who underwent endoscopy for screening or follow-up. A rodent model of reflux induced esophageal carcinogenesis was created with an esophago-gastro-jejunostomy. CD80 expression was increased in epithelial cells during metaplasia in the inflammatory esophageal carcinogenesis cascade. Cd80 null mice as well as WT mice that received antiCD80 antibodies showed a higher rate of dysplasia and KI-67+ cells. These results suggest that CD80 mediates an active immune surveillance process in early inflammation-driven esophageal carcinogenesis.

PD-L1 expression, CD8+ and CD4+ lymphocyte rate are predictive of pathological complete response after neoadjuvant chemoradiotherapy for squamous cell cancer of the thoracic esophagus.

BACKGROUND: Neoadjuvant chemoradiotherapy (CTRT) can effectively downstage esophageal squamous cell carcinoma (SCC) in patients with locally advanced disease and prolonged survival have been observed in patients with a pathological complete response (ypCR). AIMS AND METHODS: This exploratory study aimed to identify immunological predictors of pCR after neoadjuvant CTRT within SCC microenvironment. The tumor regression after neoadjuvant therapy was measured according to the Mandard score system. Eighty-eight consecutive patients with SCC of the thoracic esophagus who received neoadjuvant CTRT were included in this retrospective study. Inclusion criteria were neoadjuvant CTRT and the availability of representative histological samples taken at diagnosis. We investigated immunohistochemical expression of CD4, Tbet, FoxP3, CD8, CD80, PD-L1, and PD-1, in the pretreatment biopsies and correlated the immunohistochemical profiles to patients' outcomes. RESULTS: After neoadjuvant CTRT, 23 patients had pCR, while 65 ones had partial response, stable disease or progression. PD-L1 expression and CD8+ and CD4+ lymphocyte rate were significantly higher in patients who had ypCR compared to those who had not (10 (0-55) vs 0 (0-0), P = 0.004, 73 (36-147) vs 21 (7-47), P = 0.0006 and 39 (23-74) vs 5 (0-13), P < 0.0001 respectively). The accuracy of expression of PD-L1+, CD8+, and CD4+ lymphocyte rate in identifying responders was AUC = 0.76 (P = 0.001), AUC = 0.81 (P = 0.0001) and AUC = 0.75 (P = 0.0001), respectively. Within the ypCR group, all patients with high infiltration of CD4+ T cell recurred/relapsed while only the 38.9% of those with low CD4+ T cell infiltration did the same (P = 0.058). CONCLUSIONS: PD-L1 expression and CD8+ and CD4+ lymphocyte rate were predictive of ypCR after neoadjuvant CTRT for SCC of the thoracic esophagus with adequate accuracy. Furthermore, recurrence/relapse was associated with high level of CD4+ T cell infiltration. However, the small sample size prevented to draw definitive conclusions; further studies are necessary to evaluate the prognostic role of these markers.

Weak Cytotoxic T Cells Activation Predicts Low-Grade Dysplasia Persistence in Ulcerative Colitis.

INTRODUCTION: In patients with ulcerative colitis (UC), dysplasia develops in 10%-20% of cases. The persistence of low-grade dysplasia (LGD) in UC in 2 consecutive observations is still an indication for restorative proctocolectomy. Our hypothesis is that in the case of weak cytotoxic activation, dysplasia persists. We aimed to identify possible immunological markers of LGD presence and persistence. METHODS: We prospectively enrolled 112 UC patients who underwent screening colonoscopy (T0) who had biopsies taken from their sigmoid colon. Ninety of them had at least a second colonoscopy (T1) with biopsies taken in the sigmoid colon and 8 patients had dysplasia in both examinations suggesting a persistence of LGD in their colon. Immunohistochemistry and real time polymerase chain reaction for CD4, CD69, CD107, and CD8ß messenger RNA (mRNA) expression and flow cytometry for epithelial cells expressing CD80 or HLA avidin-biotin complex were performed. Non-parametric statistics, receiver operating characteristic curves analysis, and logistic multiple regression analysis were used. RESULTS: Thirteen patients had LGD diagnosed at T0. The mucosal mRNA expression of CD4, CD69, and CD8ß was significantly lower than in patients without dysplasia (P = 0.033, P = 0.046 and P = 0.007, respectively). A second colonoscopy was performed in 90 patients after a median follow-up of 17 (12-25) months and 14 of the patients were diagnosed with LGD. In these patients, CD8ß mRNA expression at T0 was significantly lower in patients without dysplasia (P = 0.004). A multivariate survival analysis in a model including CD8ß mRNA levels and age >50 demonstrated that both items were independent predictors of dysplasia at follow-up (hazard ratio [HR] = 0.47 [95% confidence interval [CI]: 0.26-0.86], P = 0.014, and HR = 13.32 [95% CI: 1.72-102.92], P = 0.013). DISCUSSION: These data suggest a low cytotoxic T cell activation in the colonic mucosa of UC patients who do not manage to clear dysplasia. Thus, low level of CD8ß mRNA expression in non-dysplastic colonic mucosa might be considered in future studies about the decision making of management of LGD in UC.

Epithelial CD80 promotes immune surveillance of colonic preneoplastic lesions and its expression is increased by oxidative stress through STAT3 in colon cancer cells.

BACKGROUND: One of the most potent costimulatory molecules involved in the recognition and killing of tumor cells is CD80. However, its role and the molecular mechanisms regulating its expression in sporadic colorectal carcinogenesis remain elusive. Here, we provide evidence for CD80 overexpression in human colon epithelial cells derived from preneoplastic mucosa. METHODS: Expression of CD80 on colonic epithelial cells isolated from normal human colonic mucosa, preneoplastic and neoplastic specimens was assessed by flow cytometry. WT and CD80KO mice received azoxymethane to induce colon preneoplastic lesions and sacrificed to perform histology, flow cytometry analysis and immunohistochemistry of colonic mucosa. Some WT mice were treated with a monoclonal anti-CD80 antibody following AOM administration. Primary colon epithelial cells and CT26 cell line were used to quantify the expression of CD80 in response to pro-oxidant stimuli. Specific pharmacological inhibitors and siRNA silencing were used to inhibit MAPK pathways and STAT3. RESULTS: CD80 expression was significantly increased in colon epithelial cells of human preneoplastic lesions. In the AOM model, CD80 impairment by administration of neutralizing antibodies or use of CD80 knockout mice enhanced dysplasia development. In vitro, CD80 upregulation was induced by oxidative stress in colon cancer cells and primary colon epithelial cells. In addition, reactive oxygen species could induce CD80 expression via the JNK and p38 MAPK pathways, that activated STAT3 transcription factor in colon cancer epithelial cells. CONCLUSION: This study provide evidence for a major role of CD80 in orchestrating immune surveillance of colon preneoplastic lesions and might help to develop novel approaches that exploit anti-tumor immunity to prevent and control colon cancer.

Squamous cell carcinoma antigen 1 is associated to poor prognosis in esophageal cancer through immune surveillance impairment and reduced chemosensitivity.

Squamous cell carcinoma antigen-1 (SCCA1) overexpression is associated with poor prognosis and chemoresistance in several tumor types, however, the underlying mechanisms remain elusive. Here, we report SCCA1 in relation to the immune and peritumoral adipose tissue microenvironment in early and advanced esophageal adenocarcinoma (EAC). In our series of patients with EAC, free SCCA1 serum levels were associated with significantly worse overall survival, and SCCA1-IgM serum levels showed a trend to a worse overall survival. Serum SCCA1 and intratumoral SCCA1 were inversely correlated with immune activation markers. In agreement with these findings, SCCA1 induced the expression of the immune checkpoint molecule programmed death ligand-1 on monocytes and a direct correlation of these 2 molecules was observed in sequential tumor sections. Furthermore, SCCA1 mRNA expression within the tumor was inversely correlated with stem cell marker expression both within the tumor and in the peritumoral adipose tissue. In vitro, in EAC cell lines treated with different chemotherapeutic drugs, cell viability was significantly modified by SCCA1 presence, as cells overexpressing SCCA1 were significantly more resistant to cell death. In conclusion, poor prognosis in EAC overexpressing SCCA1 is due to reduced tumor chemosensitivity as well as intratumoral immunity impairment, likely induced by this molecule.