An ex vivo readout for evaluation of dendritic cell-induced autologous cytotoxic T lymphocyte responses against esophageal cancer

The anticancer effects of curcumin and clinical research progress on its effects on esophageal cancer

Esophageal cancer (EC) is a common tumor of the gastrointestinal system and a major threat to human health. The etiology and incidence of EC vary depending on the type of pathology. Owing to the unique physiological structure of the esophagus and the poor biological behavior of EC, the treatment modalities available are limited, and the prognosis of patients is relatively poor. Curcumin is a type of natural phytochemical belonging to the class of phenolic compounds. It exerts favorable anticancer effects on various cancers. A growing body of evidence indicates that curcumin suppresses tumor development and progression by inhibiting tumor cell proliferation, invasion, and migration, thus inducing apoptosis, regulating microRNA expression, reversing multidrug resistance, and inducing sensitivity to the therapeutic effect of chemoradiotherapy. Multiple cellular molecules, growth factors, and genes encoding proteins participating in different signaling pathways interact with each other to contribute to the complex and orderly anticancer effect. The efficacy and safety of curcumin have been established in preclinical studies for EC and clinical trials for other cancers. However, the low bioavailability of curcumin limits its clinical application. Therefore, the modification of curcumin analogs, the combination of curcumin with other drugs or therapies, and the use of novel nanocarriers have been widely investigated to improve the clinical effects of curcumin in EC.

CSMD1 Mutation Related to Immunity Can Be Used as a Marker to Evaluate the Clinical Therapeutic Effect and Prognosis of Patients with Esophageal Cancer

INTRODUCTION

As a highly aggressive tumor with a poor prognosis, esophageal cancer (ESCA)'s relationship with gene mutations is unclear. Therefore, we tried to explore the role of gene mutation in ESCA progression and its relationship with immune response, clinical treatment, and prognosis.

METHODS

In addition to copy number variation (CNV) situations of common genes obtained from 2 public databases, the relationship between mutations and prognosis/tumor mutational burden (TMB) was also analyzed. Kaplan-Meier survival and Cox regression analysis were used to identify the CSMD1 mutation status as an independent predictor of prognosis. We also enriched related functions and pathways. Next, the relationship between 22 immune cells and CSMD1 mutation status was analyzed. In addition to the differences in the expression levels of immune checkpoint inhibitors (ICIs)-related genes between the high TMB and low TMB groups, the differences in the expression levels of ICIs/m6a/multi-drug resistance-related genes and the sensitivity of three chemotherapeutic drugs between CSMD1 mutant and the wild group were also compared. In addition to differences and prognostic analysis of CSMD1 expression, the correlation analysis between the expression of these genes/immune cells and the expression of CSMD1 was also performed. Finally, a nomogram that could efficiently and conveniently predict the survival probability of ESCA patients was constructed and verified.

RESULTS

We obtained 17 frequently mutated genes distribution. Mutation and loss of CSMD1 are frequent in ESCA. Only CSMD1 mutation can be used as an independent predictor of poor prognosis. Patients in the high TMB group have a lower survival probability. Wild CSMD1 may be involved in immune-related pathways. More helper T cells and fewer resting state dendritic cells were found in the CSMD1 mutant group. The PD-1 expression in the high TMB group showed higher. Paclitaxel sensitivity and ABCC1 expression were higher in the wild CSMD1 group. Most cancers show differential expression of CSMD1. Except for the prognosis of ESCA, the expression of CSMD1 is related to immune cell content and the expression of ICIs/m6a/multi-drug resistance related genes.

DISCUSSION

CSMD1 mutation could be used as an immune-related biomarker to predict prognosis and treatment effect of paclitaxel. Mutation and loss of CSMD1 may promote the progression of ESCA.

Esophageal Microenvironment: From Precursor Microenvironment to Premetastatic Niche

Esophageal cancer (EC) is the sixth most deadly cancer, and its incidence is still increasing year by year. Although the researches on the molecular mechanisms of EC have been widely carried out and incremental progress has been made, its overall survival rate is still low. There is cumulative evidence showing that the esophageal microenvironment plays a vital role in the development of EC. In precancerous lesions of the esophagus, high-risk environmental factors can promote the development of precancerous lesions by inducing the production of inflammatory factors and the recruitment of immune cells. In the tumor microenvironment, tumor-promoting cells can inhibit anti-tumor immunity and promote tumor progression through a variety of pathways, such as bone marrow-derived suppressor cells (MDSCs), tumor-associated fibroblasts (CAFs), and regulatory T cells (Tregs). The formation of extracellular hypoxia and acidic microenvironment and the change of extracellular matrix stiffness are also important factors affecting tumor progression and metastasis. Simultaneously, primary tumor-derived cytokines and bone marrow-derived immune cells can also promote the formation of pre-metastasis niche of EC lymph nodes, which are beneficial to EC lymph node metastasis. Further research on the specific mechanism of these processes in the occurrence, development, and metastasis of each EC subtype will support us to grasp the overall pre-cancerous prevention, targeted treatment, and metastatic assessment of EC.

A Dendritic Cell Vaccine Combined With Radiotherapy Activates the Specific Immune Response in Patients With Esophageal Cancer

Dendritic cells (DC) are highly efficient antigen-presenting cells. DC may be used to create DC vaccines against cancer, but the optimal strategies remain to be elucidated. This study aimed to examine the benefits and adverse effects of using esophageal cancer cell antigens to stimulate DC to trigger the specific immune response in patients with esophageal cancer undergoing radiotherapy. This was an observational cohort study performed at Lianshui County People's Hospital between September 2010 and June 2012. Forty patients with esophageal cancer planned to receive radiotherapy were selected, and 28 received the DC vaccine. DC were isolated, loaded with antigens, and intradermally injected after being cultured for 1 week. One week after injection, the patients underwent a delayed-type hypersensitivity test. Serum Th1 cytokines [interleukin (IL)-2, IL-12, and interferon (IFN)-γ] and antigen-specific IFN-γCD8 T cells were tested before and after vaccination. Patients were followed up for 2 years. Adverse events were monitored. Patients in the vaccine group tolerated the DC vaccine. Levels of serum IL-2 (+92.4%), IL-12 (+70.9%), and IFN-γ (+214.3%) as well as the proportion of IFN-γCD8 T cells (3.0-16.4-fold) were significantly increased compared with baseline and the control group (all P<0.05). The 1- (82.1% vs. 50.0%, P=0.04) and 2-year survival (67.8% vs. 33.3%, P=0.04) was improved by vaccination. Only 2 patients showed mild fever. In conclusion, the DC vaccine triggered the specific immune response and induced the secretion of Th1 cytokines. The vaccine may lead to better survival, but this have to be confirmed. Adverse events were rare and mild.

Pemetrexed plus dendritic cells as third-line therapy for metastatic esophageal squamous cell carcinoma

This study was conducted to evaluate the toxicity and efficacy of pemetrexed plus dendritic cells (DCs) when administered as third-line treatment for metastatic esophageal squamous cell carcinoma (ESCC). All patients in the study group had previously failed first-line treatment with 5-fluorouracil and cisplatin-based regimens, as well as second-line treatment with taxane-based regimens. A total of 31 patients were treated with pemetrexed (500 mg/m²) plus DCs on day 1, every 3 weeks. DCs were given for one cycle of 21 days. Thirty patients were evaluated for their response. No patient had a complete response, three patients (10.0%) had a partial response, ten patients (33.3%) had stable disease, and 17 patients (56.7%) had progressive disease. The overall response rate was 10.0%. The median progression-free survival (PFS) time was 2.9 months (95% CI, 2.7–3.2), and the median overall survival (OS) time was 7.1 months (95% CI, 6.4–7.9). The median PFS and OS times among patients with high and low levels of miR-143 expression in their blood serum were significantly different: median PFS times =3.2 months (95% CI, 2.9–3.4) and 2.7 months (95% CI, 2.4–3.0), respectively (P=0.017), and median OS times =7.8 months (95% CI, 6.8–8.9) and 6.3 months (95% CI, 5.3–7.3), respectively (P=0.036). No patient experienced Grade 4 toxicity. Combined third-line treatment with pemetrexed and DCs was marginally effective and well tolerated in patients with advanced ESCC. Serum miR-143 levels are a potential biomarker for predicting the efficacy of pemetrexed plus DCs in the treatment of ESCC.

Nano-curcumin inhibits proliferation of esophageal adenocarcinoma cells and enhances the T cell mediated immune response

In Western countries the incidence of the esophageal adenocarcinoma (EAC) has risen at a more rapid rate than that of any other malignancy. Despite intensive therapies this cancer is associated with extreme high morbidity and mortality. For this reason, novel effective therapeutic strategies are urgently required. Dendritic Cell (DC)-based immunotherapy is a promising novel treatment strategy, which combined with other anti-cancer strategies has been proven to be beneficial for cancer patients. Curcumin (diferuloylmethane), is a natural polyphenol that is known for its anti-cancer effects however, in it's free form, curcumin has poor bioavailability. The aim of this study was to investigate whether using a highly absorptive form of curcumin, dispersed with colloidal nano-particles, named Theracurmin would be more effective against EAC cells and to analyze if this new compound affects DC-induced T cell response. As a result, we show efficient uptake of nano-curcumin by the EAC cell lines, OE33, and OE19. Moreover, nano-curcumin significantly decreased the proliferation of the EAC cells, while did not affect the normal esophageal cell line HET-1A. We also found that nano-curcumin significantly up-regulated the expression of the co-stimulatory molecule CD86 in DCs and significantly decreased the secretion of pro-inflammatory cytokines from in vitro activated T cells. When we combined T cells with nano-curcumin treatment in OE19 and OE33, we found that the basic levels of T cell induced cytotoxicity of 6.4 and 4.1%, increased to 15 and 13%, respectively. In conclusion, we found that nano-curcumin is effective against EAC, sensitizes EAC cells to T cell induced cytotoxicity and decreases the pro-inflammatory signals from T cells. Combining DC immunotherapy with nano-curcumin is potentially a promising approach for future treatment of EAC.

Trastuzumab mediated T-cell response against HER-2/neu overexpressing esophageal adenocarcinoma depends on intact antigen processing machinery

Background

Esophageal adenocarcinoma (EAC) is a highly aggressive disease with poor prognosis, which frequently exhibits HER-2 gene amplification. Trastuzumab, the humanized antibody against HER-2, has potent growth inhibitory effects on HER-2 overexpressing cancers. One effect of trastuzumab is that it causes HER-2 receptor internalization and degradation, enhancing presentation of HER-2 epitopes on MHC-Class I molecules. This enhances the ability of HER-2 specific cytotoxic T lymphocytes (CTLs) to recognize and kill cancer cells. Novel strategies targeting the HER-2 receptor either directly by trastuzumab and/or indirectly by inducing a CTL response against HER-2 epitopes with, for instance, DC immunotherapy and consequently combining these strategies might prove to be very effective.

Methodology/Principal Findings

In this study we report that trastuzumab has potent growth inhibitory effects on two HER-2 overexpressing EAC cell lines OE33 and OE19. However, we found that trastuzumab and HER-2 specific CTLs act synergistically in inducing tumor lysis in OE33 but not in OE19. We discovered that in OE19 this deficient response is due to a down-regulation of the Transporter Associated with Antigen Processing-2 (TAP-2). TAP-2 is an important member of the Antigen Processing Machinery (APM), and is one of the essential elements for loading antigens on MHC class I molecules. Importantly, we demonstrated that by inducing re-expression of TAP-2 in OE19 with INF-γ treatment or by incubating the cells with INF-γ producing CTLs, the specific anti HER-2 CTL tumor lysis response and synergistic effect with trastuzumab can be restored.

Conclusion

An inefficient response of HER-2 overexpressing EAC to trastuzumab and/or DC immunotherapy can be due to a down-regulated TAP-2 expression and thus a deficient APM. Future studies combining trastuzumab with IFN-γ and/or immune-therapies inducing potent anti HER-2 CTL responses could lead to an effective combinatorial strategy for successful treatment of HER-2 overexpressing but APM defective cancers.

Induction of cytotoxic T lymphocytes primed with tumor RNA-loaded dendritic cells in esophageal squamous cell carcinoma: preliminary step for DC vaccine design

Background

Dendritic Cells (DC) are potent antigen presenting cells with the ability to prime naïve T cells and convert them to cytotoxic T-lymphocytes (CTL). We evaluated the capability of autologous DCs transfected with total tumor and normal RNA to induce cytotoxic CTL as the preliminary step to design a DC-based vaccine in the esophageal squamous cell carcinoma (ESCC).

Methods

Monocytes-derived DCs were electroporated with either total tumor RNA or normal RNA. T cells were then primed with tumor RNA transfected DCs and lytic effects of the generated CTL were measured with Cytotoxicity assay and IFN-γ Release Elispot assay.

Results

Cytotoxicity was induced against DCs loaded with tumoral RNA (%24.8 ± 5.2 SEM) while in normal RNA-loaded DCs, it was minimal (%6.1 ± 2.4 SEM) and significantly lower (p < 0.05). INF-γ secretion was more than 2-folds higher in tumoral RNA-loaded DCs when compared with normal RNA-loaded DCs (p < 0.05).

Conclusion

Electroporating DCs with tumor RNA generated tumor antigen presenting cells which in turn enhanced cytotoxic effects of the T cells against ESCC. This may be a useful autologous ex vivo screening tool for confirming the lytic effects of primed T cells on tumors and evaluate probable further adverse effects on noncancerous tissues. These data provide crucial preliminary information to establish a total tumor RNA-pulsed DC vaccine therapy of ESCC.

Dendritic cells in Barrett's esophagus and esophageal adenocarcinoma

BACKGROUND

Like other premalignant conditions that develop in the presence of chronic inflammation, the development and progression of Barrett's esophagus is associated with the development of an immune response, but how this immune response is regulated is poorly understood. A comprehensive literature search failed to find any report of the presence of dendritic cells in Barrett's intestinal metaplasia and esophageal adenocarcinoma and this prompted our study.

MATERIAL AND METHODS

We used immunohistochemical staining and electron microscopy to examine whether dendritic cells are present in Barrett's esophagus and esophageal adenocarcinoma. Immunohistochemical staining with CD83, a specific marker for dendritic cells, was performed on paraffin-embedded sections of Barrett's intestinal metaplasia (IM, n = 12), dysplasia (n = 11) and adenocarcinoma (n = 14).

RESULTS

CD83+ cells were identified in the lamina propria surrounding intestinal type glands in Barrett's IM, dysplasia, and cancer tissues. Computerized quantitative analysis showed that the numbers of dendritic cells were significantly higher in cancer tissues. Double immunostaining with CD83, CD20, and CD3, and electron microscopy demonstrated that dendritic cells are present in Barrett's esophagus and form clusters with T cells and B cells directly within the lamina propria.

CONCLUSIONS

These findings demonstrate that dendritic cells are present in Barrett's tissues, with a significant increase in density in adenocarcinoma compared to benign Barrett's esophagus. Dendritic cells may have a role in the pathogenesis and immunotherapy treatment of Barrett's esophagus and adenocarcinoma.