Cytotoxic potential despite impaired activation pathways in T lymphocytes infiltrating nasopharyngeal carcinoma

Unfolding the Complexity of Exosome-Cellular Interactions on Tumour Immunity and Their Clinical Prospects in Nasopharyngeal Carcinoma

Nasopharyngeal carcinoma (NPC) is an epithelial malignancy situated in the posterolateral nasopharynx. NPC poses grave concerns in Southeast Asia due to its late diagnosis. Together with resistance to standard treatment combining chemo- and radiotherapy, NPC presents high metastatic rates and common recurrence. Despite advancements in immune-checkpoint inhibitors (ICIs) and cytotoxic-T-lymphocytes (CTLs)-based cellular therapy, the exhaustive T cell profile and other signs of immunosuppression within the NPC tumour microenvironment (TME) remain as concerns to immunotherapy response. Exosomes, extracellular vesicles of 30-150 nm in diameter, are increasingly studied and linked to tumourigenesis in oncology. These bilipid-membrane-bound vesicles are packaged with a variety of signalling molecules, mediating cell-cell communications. Within the TME, exosomes can originate from tumour, immune, or stromal cells. Although there are studies on tumour-derived exosomes (TEX) in NPC and their effects on tumour processes like angiogenesis, metastasis, therapeutic resistance, there is a lack of research on their involvement in immune evasion. In this review, we aim to enhance the comprehension of how NPC TEX contribute to cellular immunosuppression. Furthermore, considering the detectability of TEX in bodily fluids, we will also discuss the potential development of TEX-related biomarkers for liquid biopsy in NPC as this could facilitate early diagnosis and prognostication of the disease.

Mechanisms of Anergic Inflammatory Response in Nasopharyngeal Carcinoma Cells Despite Ubiquitous Constitutive NF-κB Activation

Commensal microbes cross talk with their colonized mucosa. We show that microbes and their cell wall components induce an inflammatory response in cultured human mucosal cells derived from the nonmalignant nasopharyngeal epithelium (NNE) cells in vitro. NNE cells show significant induction of NF-κB with nuclear shuttling and inflammatory gene response when exposed to Gram-positive bacteria (streptococci) or peptidoglycan (PGN), a component of the Gram-positive bacterial cell wall. This response is abrogated in nasopharyngeal carcinoma (NPC)–derived cell lines. The inflammatory response induced by NF-κB signaling was blocked at two levels in the tumor-derived cells. We found that NF-κB was largely trapped in lipid droplets (LDs) in the cytoplasm of the NPC-derived cells, while the increased expression of lysine-specific histone demethylase 1 (LSD1, a repressive nuclear factor) reduces the response mediated by remaining NF-κB at the promoters responding to inflammatory stimuli. This refractory response in NPC cells might be a consequence of long-term exposure to microbes in vivo during carcinogenic progression. It may contribute to the decreased antitumor immune responses in NPC, among others despite heavy T-helper cell infiltration, and thus facilitate tumor progression.

A lncRNA signature associated with tumor immune heterogeneity predicts distant metastasis in locoregionally advanced nasopharyngeal carcinoma

Increasing evidence has revealed the roles of long noncoding RNAs (lncRNAs) as tumor biomarkers. Here, we introduce an immune-associated nine-lncRNA signature for predicting distant metastasis in locoregionally advanced nasopharyngeal carcinoma (LA-NPC). The nine lncRNAs are identified through microarray profiling, followed by RT-qPCR validation and selection using a machine learning method in the training cohort (n = 177). This nine-lncRNA signature classifies patients into high and low risk groups, which have significantly different distant metastasis-free survival. Validations in the Guangzhou internal (n = 177) and Guilin external (n = 150) cohorts yield similar results, confirming that the signature is an independent risk factor for distant metastasis and outperforms anatomy-based metrics in identifying patients with high metastatic risk. Integrative analyses show that this nine-lncRNA signature correlates with immune activity and lymphocyte infiltration, which is validated by digital pathology. Our results suggest that the immune-associated nine-lncRNA signature can serve as a promising biomarker for metastasis prediction in LA-NPC.

Differences in oncological outcomes and inflammatory biomarkers between right-sided and left-sided stage I-III colorectal adenocarcinoma

BACKGROUND

The aim of this study was to investigate the differences in oncological outcome and inflammatory biomarkers between right-sided colon cancer (RCC) and left-sided colorectal cancer (LCRC).

METHODS

We retrospectively analyzed 339 patients with stage I-III colorectal cancer, including 125 RCC patients and 214 LCRC patients, who underwent radical resection from January 2012 to January 2014. Comparison of neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR) between RCC and LCRC was evaluated using the Mann-Whitney U test. Overall survival (OS) and disease-free survival (DFS) were analyzed using Kaplan-Meier analysis and compared using the log-rank test. Univariate and multivariate Cox regression analyses were used to identify the prognostic value of inflammatory markers.

RESULTS

Patients with RCC had higher NLR (P = .002) and PLR (P < .001) but lower LMR (P = .002) compared to LCRC. In stage I-III, RCC showed poorer OS and DFS than LCRC (61.6% vs 71.5%, P = .018; 64.8% vs 76.2%, P = .006). Univariate and multivariate analyses indicated that NLR, PLR, and LMR were independent predictors for both OS and DFS in RCC, whereas only PLR was found to be an independent prognostic predictor in LCRC.

CONCLUSION

The prognosis and prognostic value of inflammatory biomarkers were significantly different between RCC and LCRC. Novel therapeutic strategies are needed, and proper prognostic predictors should be selected according to colorectal tumor location.

Evaluation of Red Cell Distribution Width to Lymphocyte Ratio as Potential Biomarker for Detection of Colorectal Cancer

Background and Aim

Colorectal cancer (CRC) is the third most lethal cancer globally. This study sought to determine the feasibility of using red cell distribution width-to-lymphocyte ratio (RLR) as a tool to facilitate CRC detection.

Methods

Seventy-eight healthy controls, 162 patients diagnosed with CRC, and 94 patients with colorectal polyps (CP) from June 2017 to October 2018 were retrospectively reviewed. Clinical data were obtained to analyze preoperative RLR level, and receiver operating characteristic (ROC) curve analysis was performed to estimate the potential role of RLR as a CRC biomarker.

Results

RLR was higher in patients with CRC than in healthy participants (P < 0.05). ROC analysis indicated that combined detection of RLR and CEA appears to be a more effective marker to distinguish among controls, CP, and CRC patients, yielding 56% sensitivity and 90% specificity. RLR levels were significantly greater in those who had more advanced TNM stages (P < 0.05) and patients with distant metastasis stages (P < 0.05).

Conclusions

RLR might serve as a potential biomarker for CRC diagnosis.

Potential Diagnostic Value Of Combining Inflammatory Cell Ratios With Carcinoembryonic Antigen For Colorectal Cancer

PURPOSE

To evaluate the diagnostic value of combining the neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR) or lymphocyte-monocyte ratio (LMR) with carcinoembryonic antigen (CEA) in patients with colorectal cancer (CRC).

PATIENTS AND METHODS

The diagnostic performance of inflammatory makers and CEA was evaluated in cohort 1 (664 patients with CRC, 336 patients with colorectal polyps and 664 healthy controls) and validated in cohort 2 (87 patients with CRC and 87 healthy controls) by using receiver operating characteristic curve analysis.

RESULTS

In cohort 1, the NLR, PLR and CEA levels were significantly higher, while the LMR was markedly lower in patients with CRC than in healthy controls. The PLR and LMR were significantly associated with invasion depth and lymph node metastasis. Moreover, significant differences in the PLR and LMR were observed between patients with stage I/II CRC and healthy or polyp controls and those with stage III/IV CRC. Using the NLR, PLR or LMR with CEA resulted in a significantly larger area under the curve (AUC) than any of them used alone. Combining the PLR and LMR with CEA exhibited the best diagnostic value for CRC (AUC=0.892). The AUCs of this combination were 0.864 and 0.783 for distinguishing stage I/II CRC from healthy and polyp controls, respectively. When we used the same cut-off values to assess the diagnostic ability of these markers in cohort 2, similar results were observed, and the PLR, LMR and CEA combination also showed the highest accuracy (AUC=0.936).

CONCLUSION

Combining inflammatory cell ratios with CEA could improve the diagnostic efficacy for CRC patients. The combination of the PLR and LMR with CEA might be a valuable indicator in the early detection and monitoring of CRC patients.

The Microenvironment in Epstein-Barr Virus-Associated Malignancies

The Epstein–Barr virus (EBV) can cause a wide variety of cancers upon infection of different cell types and induces a highly variable composition of the tumor microenvironment (TME). This TME consists of both innate and adaptive immune cells and is not merely an aspecific reaction to the tumor cells. In fact, latent EBV-infected tumor cells utilize several specific mechanisms to form and shape the TME to their own benefit. These mechanisms have been studied largely in the context of EBV+ Hodgkin lymphoma, undifferentiated nasopharyngeal carcinoma, and EBV+ gastric cancer. This review describes the composition, immune escape mechanisms, and tumor cell promoting properties of the TME in these three malignancies. Mechanisms of susceptibility which regularly involve genes related to immune system function are also discussed, as only a small proportion of EBV-infected individuals develops an EBV-associated malignancy.

Prognostic significance of tumor-infiltrating lymphocytes in nondisseminated nasopharyngeal carcinoma: A large-scale cohort study

The American Joint Committee on Cancer (AJCC) staging system is inadequate for an accurate prognosis in nasopharyngeal carcinoma (NPC). Thus, new biomarkers are under intense investigation. Here, we investigated whether the density of TILs could predict prognosis in NPC. First, we used 1490 cases of nasopharyngeal carcinoma samples from two independent cohorts to evaluate the density and distribution of tumor-infiltrating lymphocytes (TILs). Second, in one cohort, we assessed associations between TILs and clinical outcomes in 593 randomly selected samples (defined as the training set) and validated findings in the remaining 593 samples (defined as the validation set). Furthermore, we confirmed the prognostic value of TILs in a second independent cohort of 304 cases (defined as the independent set). Based on multivariable Cox regression analysis, we also established an effective prognostic nomogram including TILs to improve accuracy in predicting disease-free survival (DFS) for patients with nondisseminated NPC. We found that high TILs in the training set were significantly associated with favorable DFS [hazard ratio (HR) 0.41, 95% confidence interval (CI) 0.28-0.58, p < 0.001], overall survival (OS, HR 0.42, 95% CI 0.27-0.64, p < 0.001), distant metastasis-free survival (DMFS, HR 0.37, 95% CI 0.23-0.58, p < 0.001) and local-regional recurrent free survival (LRRFS, HR 0.43, 95% CI 0.25-0.73, p = 0.002). Multivariate analysis showed that TILs are an independent prognostic indicator for DFS in all cohorts. In summary, this study indicated that TILs may reflect the immunological heterogeneity of NPC and could represent a new prognostic biomarker.

The biology and function of extracellular vesicles in nasopharyngeal carcinoma (Review)

Extracellular vesicles are a heterogeneous group of membrane-enclosed vesicles, which play an important role in intercellular communication. Increasing number of studies have shown that tumor-derived extracellular vesicles might be involved in the transfer of oncogenic cargo (proteins, lipids, messenger RNA, microRNA, non-coding RNAs and DNA) through which cancer cells could shape the tumor microenvironment and influence tumor progression. Nasopharyngeal carcinoma-derived extracellular vesicles have also reported to facilitate tumor proliferation, metastasis and immune escape. Moreover, nasopharyngeal carcinoma-derived extracellular vesicles might serve as biomarkers for early diagnosis and therapeutic targets. The present review provides information on the biological and clinical significance of extracellular vesicles in tumors, especially in nasopharyngeal carcinoma.

Prognostic role of tumor infiltrating lymphocytes in EBV positive and EBV negative nasopharyngeal carcinoma

OBJECTIVES

Tumor infiltrating lymphocytes (TILs) correlate with both better and worse prognosis in solid tumors. As therapeutic modalities for nasopharyngeal carcinoma (NPC) are limited, immunotherapy could be a potential alternative. Up till now there is limited prognostic data on the role of TILs in NPC, so we assessed the prognostic role of TILs in Epstein-Barr-virus (EBV) positive and negative NPC.

METHODS

Tissue of 92 NPCs was assessed for CD3, CD4, CD8, PD1 and PDL1 expression in the tumor's micro-environment. Correlations between clinicopathological characteristics was assessed using the Pearson X² test, Fisher's exact test and ANOVA. Survival was analyzed with the Kaplan-Meier method and Cox regression. Differences in CD3, CD4, CD8, PD1, PDL1 counts/(co)expression between EBV positive and negative NPCs were evaluated using the Mann-Whitney U test. Two-tailed P values below 0.05 were considered statistically significant.

RESULTS

EBV positive NPC contains significantly more CD3, CD4 and CD8 TILs than EBV negative NPC. In the whole NPC group, increased CD8 count is associated with better overall survival (OS) (HR 0.219 (95%CI 0.075-0.640)), but also in cases with PDL1 co-expression (HR 0.073 (95%CI 0.010-0.556)). In EBV positive NPC co-expression of CD8 and PDL1 showed better disease free survival (HR 0.407 (95%CI 0.195-0.850)) and OS (HR 0.170 (95%CI 0.037-0.787)).

CONCLUSIONS

Although TILs are significantly different between EBV positive and negative NPCs, it is especially composition of the infiltrate which determines prognosis. Effects of PD1 and CD8 need more study, because these findings show much potential in using immunotherapeutic modalities in NPC treatment.

A prognostic model to predict survival in stage III colon cancer patients based on histological grade, preoperative carcinoembryonic antigen level and the neutrophil lymphocyte ratio

BACKGROUND

Stage III colon cancer patients demonstrate diverse clinical outcomes. The aim of this study was to develop a prognostic model in order to better predict their survival.

MATERIALS AND METHODS

From 2004 to 2010, 548 patients were retrospectively analyzed, among whom 328 were defined as the study group and the remaining 220 served as a validation group. Clinico-pathologic features, including age, gender, histological grade, T stage, number of positive lymph nodes, number of harvest lymph nodes, pretreatment carcinoembryonic antigen (CEA) levels and pretreatment neutrophil lymphocyte ratio (NLR), were collected. Kaplan-Meier survival curves were used to detect prognostic factors and multivariate analysis was applied to identify independent examples on which to develop a prognostic model. Finally, the model was further validated with the validation group.

RESULTS

Histological grade (p=0.002), T stage (p=0.011), number of positive lymph nodes (p=0.003), number of harvested lymph nodes (p=0.020), CEA (p=0.005), and NLR (p<0.001) were found as prognostic factors while histological grade [RR(relative risk):0.632, 95%CI (Confidence interval) 0.405~0.985, p=0.043], CEA (RR:0.644, 95%CI:0.431~0.964, p=0.033) and NLR (RR:0.384, 95%CI:0.255~0.580, p<0.001) levels were independent. The prognostic model based on these three factors was able to classify patients into high risk, intermediate and low risk groups (p<0.001), both in study and validation groups.

CONCLUSIONS

Histological grade, pretreatment CEA and NLR levels are independent prognostic factors in stage III colon cancer patients. A prognostic model based on these factors merits attention in future clinical practice.

Tumor-derived exosomes promote tumor progression and T-cell dysfunction through the regulation of enriched exosomal microRNAs in human nasopharyngeal carcinoma

Tumor-derived exosomes contain biologically active proteins and messenger and microRNAs (miRNAs). These particles serve as vehicles of intercellular communication and are emerging mediators of tumorigenesis and immune escape. Here, we isolated 30-100 nm exosomes from the serum of patients with nasopharyngeal carcinoma (NPC) or the supernatant of TW03 cells. Increased circulating exosome concentrations were correlated with advanced lymphoid node stage and poor prognosis in NPC patients (P < 0.05). TW03-derived exosomes impaired T-cell function by inhibiting T-cell proliferation and Th1 and Th17 differentiation and promoting Treg induction by NPC cells in vitro. These results are associated with decreases in ERK, STAT1, and STAT3 phosphorylation and increases in STAT5 phosphorylation in exosome-stimulated T-cells. TW03-derived exosomes increased the proinflammatory cytokines IL-1β, IL-6, and IL-10 but decreased IFNγ, IL-2, and IL-17 release from CD4⁺ or CD8+ T-cells. Furthermore, five commonly over-expressed miRNAs were identified in the exosomes from patient sera or NPC cells: hsa-miR-24-3p, hsa-miR-891a, hsa-miR-106a-5p, hsa-miR-20a-5p, and hsa-miR-1908. These over-expressed miRNA clusters down-regulated the MARK1 signaling pathway to alter cell proliferation and differentiation. Overall, these observations reveal the clinical relevance and prognostic value of tumor-derived exosomes and identify a unique intercellular mechanism mediated by tumor-derived exosomes to modulate T-cell function in NPC.

Lessons from rare tumors: Hepatic lymphoepithelioma-like carcinomas

In this review we focus on lymphoepithelioma-like hepatocellular carcinomas (LEL-HCC) and lymphoepithelioma-like cholangiocarcinomas (LEL-ICC). Despite their rarity, these tumors are of general interest because of their epidemiological and clinical features, and because they represent a distinct model of interaction between the immune system and neoplastic cells. Approximately half of LEL-HCC arise in the context of chronic hepatitis C virus (HCV) infection and have been described both in Eastern and Western patients. By contrast, LEL-ICC is associated in almost all cases with Epstein-Barr virus (EBV) infection and exhibits the same epidemiological features of EBV related malignancies. Compared with classical hepatocellular carcinoma and intrahepatic cholangiocarcinoma of corresponding stage, both LEL-HCC and LEL-ICC are characterized by lower rates of recurrence after surgery and better overall survival. How this behavior is related to distinct genetic alterations and tumor microenvironment is unclear. The pathophysiological mechanisms of lymphoid infiltrations seem to be different among the two groups of tumors. In fact, LEL-HCC frequently arises in the context of inflammatory changes driven by HCV infection, and has been recognized as a variant of classical hepatocellular carcinoma. At variance, lymphocyte recruitment of LEL-ICC is similar to that described in nasopharyngeal carcinoma and gastric LEL, and possibly depends on the expression pattern of latent EBV infection.

Understanding the interplay between host immunity and Epstein-Barr virus in NPC patients

Epstein-Barr virus (EBV) has been used as a paradigm for studying host-virus interactions, not only because of its importance as a human oncogenic virus associated with several malignancies including nasopharyngeal carcinoma (NPC) but also owing to its sophisticated strategies to subvert the host antiviral responses. An understanding of the interplay between EBV and NPC is critical for the development of EBV-targeted immunotherapy. Here, we summarize the current knowledge regarding the host immune responses and EBV immune evasion mechanisms in the context of NPC.

Control of the inflammatory response mechanisms mediated by natural and induced regulatory T-cells in HCV-, HTLV-1-, and EBV-associated cancers

Virus infections are involved in chronic inflammation and, in some cases, cancer development. Although a viral infection activates the immune system's response that eradicates the pathogen mainly through inflammatory mechanisms, it is now recognized that this inflammatory condition is also favorable to the development of tumors. Indeed, it is well described that viruses, such as hepatitis C virus (HCV), Epstein Barr virus (EBV), human papillomavirus (HPV) or human T-cell lymphotropic virus type-1 (HTLV-1), are important risk factors for tumor malignancies. The inflammatory response is a fundamental immune mechanism which involves several molecular and cellular components consisting of cytokines and chemokines that are released by various proinflammatory cells. In parallel to this process, some endogenous recruited components release anti-inflammatory mediators to restore homeostasis. The development of tools and strategies using viruses to hijack the immune response is mostly linked to the presence of regulatory T-cells (Treg) that can inhibit inflammation and antiviral responses of other effector cells. In this review, we will focus on current understanding of the role of natural and induced Treg in the control and the resolution of inflammatory response in HCV-, HTLV-1-, and EBV-associated cancers.

Preoperative neutrophil to lymphocyte ratio >5 is a prognostic factor for recurrent colorectal cancer

AIM

Previous studies have demonstrated that raised preoperative neutrophil to lymphocyte ratio (NLR) is associated with poor prognosis in colorectal cancer (CRC). The aim of this study was to assess whether preoperative NLR could predict patients at risk of recurrence of CRC.

METHOD

All consecutive patients who underwent surgical resection for CRC over a 2-year period at our institution were analysed. Demographic data including CRC recurrence were prospectively collected from our institutional cancer database. CRC recurrence was diagnosed on radiological and endoscopic histopathological data. Preoperative NLR was calculated on baseline blood results, with a value >5 being a poor prognostic factor. Parametric survival analysis was used to identify risk factors for CRC recurrence. Hazard ratios (HRs) were calculated for gender, CRC stage using Jass score, preoperative NLR and CRC site. P < 0.05 was considered statistically significant.

RESULTS

In all, 297 patients (157 men) underwent CRC resection at a median age of 70 years (range 23-93); 164 patients had colon cancer, 111 rectal cancer and 22 recto-sigmoid cancer. The distribution by stage of CRC was 30.2% for stage 1, 23.8% for stage 2, 19.5% for stage 3 and 26.5% for stage 4. Over a median follow-up period of 3.35 (0.1-8) years, 59 (19.8%) patients had recurrent CRC. Multivariate analysis revealed CRC stage (HR 8.69, 95% CI 3.85-19.6, P < 0.0001) and NLR >5 (HR 1.81, 95% CI 1.07-3.07, P = 0.028) to be significant and independent risk factors predictive of recurrent CRC.

CONCLUSION

These data suggest that preoperative NLR >5 is predictive of CRC recurrence.

The pathological roles of BART miRNAs in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a distinct type of head and neck cancer prevalent in south-east Asia and southern China, where it constitutes a significant health burden. Although the close association of NPC with Epstein-Barr virus (EBV) infection has been known for more than four decades, the exact role that EBV plays in the pathogenesis of this malignancy is still unclear. While NPC tumours are known to express a number of EBV-encoded proteins, they also express a large number of virus-encoded microRNAs (miRNAs), the most abundant of which are those encoded from the BamHI-A region of the viral genome: the so-called BART miRNAs. miRNAs are small non-coding mRNAs that negatively regulate the expression of various genes at the post-transcriptional level. Accumulating evidence suggests that miRNAs play important roles in tumourigenesis. Here, we review the role of EBV-encoded BART miRNAs in modulating apoptosis and host innate defence mechanisms and their contribution to NPC pathogenesis. The rationale and strategies for therapeutic targeting of BART miRNAs in EBV-infected NPC are also discussed.

CXCR6 and CCR5 localize T lymphocyte subsets in nasopharyngeal carcinoma

The substantial T lymphocyte infiltrate found in cases of nasopharyngeal carcinoma (NPC) has been implicated in the promotion of both tumor growth and immune escape. Conversely, because malignant NPC cells harbor the Epstein-Barr virus, this tumor is a candidate for virus-specific T cell-based therapies. Preventing the accumulation of tumor-promoting T cells or enhancing the recruitment of tumor-specific cytotoxic T cells offers therapeutic potential. However, the mechanisms involved in T cell recruitment to this tumor are poorly understood. Comparing memory T cell subsets that have naturally infiltrated NPC tissue with their counterparts from matched blood revealed enrichment of CD8(+), CD4(+), and regulatory T cells expressing the chemokine receptor CXCR6 in tumor tissue. CD8(+) and (nonregulatory) CD4(+) T cells also were more frequently CCR5(+) in tumor than in blood. Ex vivo studies demonstrated that both receptors were functional. CXCL16 and CCL4, unique chemokine ligands for CXCR6 and CCR5, respectively, were expressed by the malignant cells in tumor tissue from the majority of NPC cases, as was another CCR5 ligand, CCL5. The strongest expression of CXCL16 was found on tumor-infiltrating cells. CCL4 was detected on the tumor vasculature in a majority of cases. These findings suggest that CXCR6 and CCR5 play important roles in T cell recruitment and/or retention in NPC and have implications for the pathogenesis and treatment of this tumor.

Host-tumor interactions in nasopharyngeal carcinomas

Like other human solid tumors, nasopharyngeal carcinoma (NPC) is a tissue and a systemic disease as much as a cell disease. Tumor cell population in NPC is highly heterogeneous. Heavy infiltration by non-malignant leucocytes results at least in part from the production of abundant inflammatory cytokines by the malignant epithelial cells. There is indirect evidence that interactions between stromal and malignant cells contribute to tumor development. Peripheral blood samples collected from NPC patients contain multiple products derived from the tumor, including cytokines, non-cytokine tumor proteins, tumor exosomes and viral nucleic acids. These products represent a potential source of biomarkers for assessment of tumor aggressiveness, indirect exploration of cellular interactions and monitoring of tumor response to therapeutic agents. Most NPC patients are immunocompetent with evidence of active humoral and cellular immune responses against EBV-antigens at the systemic level. Tumor development is facilitated by local immunosuppressive factors which are not fully understood. Local accumulation of regulatory T-cells is probably one important factor. At least two NPC tumor products are suspected to contribute to their expansion, the cytokine CCL20 and the tumor exosomes carrying galectin 9. In the future, new therapeutic modalities will probably aim at breaking immune tolerance or at blocking cellular interactions critical for tumor growth.

Elevated neutrophil to lymphocyte ratio predicts poor prognosis in nasopharyngeal carcinoma

Elevated neutrophil to lymphocyte ratio (NLR) has been reported to be associated with worse survival in many malignancies, whereas its role in nasopharyngeal carcinoma (NPC) remains unclear. We retrospectively reviewed 363 consecutively, newly diagnosed, non-disseminated, and biopsy-proven NPC patients. Disease-specific survival (DSS), distant metastasis-free survival (DMFS), and locoregional recurrence-free survival (LRFS) rates were compared according to NLR level. Multivariate analysis was performed to assess the prognostic value of NLR. The 5-year DSS, DMFS, and LRFS rates for patients with elevated or non-elevated NLR (> or ≤3.73) were 59.6% vs. 76.6% (p = 0.03), 69.7% vs. 86.6% (p = 0.002), and 78.5% vs. 87.3% (p = 0.105), respectively. For patients with locoregionally advanced disease, NLR was not only an independent prognostic factor, but also a predictor of response to chemoradiotherapy. The 5-year DSS, DMFS, and LRFS rates for patients with elevated or non-elevated NLR were 47.2% vs. 73.7% (p < 0.001), 59.2% vs. 85.1% (p < 0.001), and 72.3% vs. 84.6% (p = 0.041), respectively. Compared with radiation alone, chemoradiotherapy significantly improved DSS and LRFS for patients with non-elevated NLR, but not for those with elevated NLR. Pre-treatment NLR is a strong prognostic factor for NPC patients. For patients with locoregionally advanced disease, NLR might also be a useful indicator for selection of treatment strategies.

Endogenous latent membrane protein 1 in Epstein-Barr virus-infected nasopharyngeal carcinoma cells attracts T lymphocytes through upregulation of multiple chemokines

Tumor-infiltrating T lymphocytes are considered to facilitate development of Epstein-Barr virus (EBV)-associated nasopharyngeal carcinoma (NPC), but how EBV in NPC tumor cells directs T cell infiltration remains unclear. Here we compare EBV-infected NPC cells with and without spontaneous expression of viral latent membrane protein 1 (LMP1) and find that culture supernatants of LMP1-positive NPC cells exert enhanced chemoattraction to primary T cells. Knockdown of endogenous LMP1 in the cells suppresses the chemotactic activity. Endogenous LMP1 in NPC cells upregulates multiple chemokines, among which MIP-1alpha, MIP-1beta and IL-8 contribute to T cell chemotaxis. We further reveal that LMP1-induced production of MIP-1alpha and MIP-1beta in NPC cells requires not only two carboxyl-terminal activation regions of LMP1 but also their downstream NF-kappaB and JNK pathways. This study corroborates that endogenous LMP1 in EBV-infected NPC cells induces multiple chemokines to promote T cell recruitment and perhaps other pathogenic events in NPC.

Reactive nitrogen species-dependent DNA damage in EBV-associated nasopharyngeal carcinoma: the relation to STAT3 activation and EGFR expression

Nasopharyngeal carcinoma (NPC) is strongly associated with Epstein-Barr virus (EBV) infection. Recently, reactive nitrogen and oxygen species are considered to participate in inflammation-related carcinogenesis through DNA damage. In our study, we obtained biopsy and surgical specimens of nasopharyngeal tissues from NPC patients in southern China, and performed double immunofluorescent staining to examine the formation of 8-nitroguanine, a nitrative DNA lesion and 8-oxo-7,8-dihydro-2'-deoxyguanosine, an oxidative DNA lesion, in these specimens. Strong DNA lesions were observed in cancer cells and inflammatory cells in stroma of NPC patients. Intensive immunoreactivity of iNOS was detected in the cytoplasm of 8-nitroguanine-positive cancer cells. DNA lesions and iNOS expression were also observed in epithelial cells of EBV-positive patients with chronic nasopharyngitis, although their intensities were significantly weaker than those in NPC patients. In EBV-negative subjects, no or little DNA lesions and iNOS expression were observed. EGFR and phosphorylated STAT3 were strongly expressed in cancer cells of NPC patients, but NF-kappaB was not expressed, suggesting that STAT3-dependent mechanism is important for NPC carcinogenesis. IL-6 was expressed mainly in inflammatory cells of nasopharyngeal tissues of EBV-infected patients. EBV-encoded RNAs (EBERs) and latent membrane protein 1 (LMP1) were detected in cancer cells from all EBV-infected patients. In vitro cell system, nuclear accumulation of EGFR was observed in LMP1-expressing cells, and IL-6 induced phosphorylated STAT3 and iNOS. These data suggest that nuclear accumulation of EGFR and STAT3 activation by IL-6 play the key role in iNOS expression and resultant DNA damage, leading to EBV-mediated NPC.

Expression of interleukin-18 by nasopharyngeal carcinoma cells: a factor that possibly initiates the massive leukocyte infiltration

Interleukin-18 (IL-18) is a single-chain cytokine that is produced by various cells. With interleukin-12 (IL-12), it synergistically stimulates activated T cells and natural killer (NK) cells to produce interferon-gamma (IFN-gamma). Nasopharyngeal carcinoma (NPC) is the most common form of nasal and nasopharyngeal malignancy, and in NPC tumor tissues there is an intense leukocyte infiltration comprising predominantly T cells and macrophages. We previously showed an increased expression of IFN-gamma in the infiltrating T cells. To identify the cells that provide IL-12 and IL-18 for stimulating the expression of IFN-gamma in activated T cells, NPC cell lines CNE-2 and HK-1, as well as biopsies obtained from NPC and control individuals, were examined. CNE-2 and HK-1 cells were found to express messenger RNA encoding IL-18, but not IL-12. Secreted IL-18 was detected in the culture supernatant. Addition of a caspase-1 inhibitor decreased the secretion level, indicating that this IL-18 secretion was caspase-1 dependent. Moreover, the in vitro IL-18 production in NPC cell lines correlated with the NPC tumor cells in situ. NPC tumor cells in the biopsies produced IL-18, as detected by immunohistochemistry and immunofluorescent double staining. In contrast, IL-18 expression was not observed in the control biopsies. We suggest that IL-18 secreted by NPC tumor cells plays a role in initiating the leukocyte infiltration process. IL-18 stimulates T cells and NK cells to produce IFN-gamma, which consequently activates macrophages and other immune cells to secrete chemokines to start a leukocyte recruitment cascade.

High numbers of granzyme B/CD8-positive tumour-infiltrating lymphocytes in nasopharyngeal carcinoma biopsies predict rapid fatal outcome in patients treated with curative intent

This study determined whether tumour-infiltrating lymphocytes (TILs) in nasopharyngeal carcinomas (NPCs) include activated cytotoxic T lymphocytes (CTLs) and whether the numbers of activated CTLs in these biopsies are related to clinical outcome. Moreover, the study investigated whether the numbers of activated CTLs are associated with the expression of MHC class I proteins and the granzyme B antagonist PI-9 in the tumour cells. Forty-three Indonesian NPC patients (T(1-3), N(1-3), M(0)), who were treated with curative intent by radiotherapy only, were studied. Tumour-infiltrating activated CTLs were detected using antibodies against granzyme B, CD8, and CD56. Expression of MHC class I proteins and PI-9 was also determined by immunohistochemistry. Granzyme B-positive TILs were detected in all NPC biopsies. The presence of a high percentage (>25%) of granzyme B-positive TILs appeared to be a very strong predictor of a rapid fatal clinical outcome, independent of stage. Complete absence of MHC class I heavy chain expression in tumour cells was observed in 11 of 31 evaluable cases and low levels were observed in seven additional cases. No association between MHC class I expression and the numbers of granzyme B-positive TILs was observed. Expression of the granzyme B antagonist PI-9 in tumour cells was detected in three cases. It is concluded that the presence of many granzyme B-positive TILs in a selected group of Indonesian NPC patients is a strong and stage-independent marker for a rapid fatal clinical outcome.

Nasopharyngeal carcinoma and the EBV-specific T cell response: prospects for immunotherapy

T cells specific for Epstein-Barr virus (EBV) can effectively target the virus-transformed B lymphoproliferative lesions that arise in immunosuppressed transplant patients. This review explores the possibility of developing similar T cell-based strategies to treat an EBV-positive epithelial tumour, nasopharyngeal carcinoma (NPC), which arises in relatively immunocompetent individuals and where EBV antigen expression in the tumour is more limited.

A distinct expression of CC chemokines by macrophages in nasopharyngeal carcinoma: implication for the intense tumor infiltration by T lymphocytes and macrophages

Nasopharyngeal carcinoma (NPC) is characterized by harboring Epstein-Barr virus genes in the tumor cells and an intense infiltration of leukocytes in the tumor tissue. These infiltrating cells are mainly composed of T lymphocytes and macrophages. The mechanism of this intense infiltration has long been a puzzle. We attempted to address this issue by studying the expression of CC chemokines, which are responsible for recruiting both T cells and macrophages, by an immunohistochemical approach. In biopsies obtained from nasopharynx of 17 NPC patients that contained tumor cells, expression of macrophage inflammatory protein 1alpha (MIP-1alpha), MIP-1beta, macrophage chemoattractant protein-1 (MCP-1), MCP-2, MCP-3, and RANTES was detected in the tumor-infiltrating cells, with MIP-1alpha and MCP-1 found in nearly all biopsies and the others relatively less frequently. Furthermore, expression of interferon-gamma (IFN-gamma) was also observed in tumor-infiltrating cells. In contrast, CC chemokines and IFN-gamma were rarely expressed in the 13 control biopsies that were either normal or with nonspecific inflammation, and in 4 biopsies from untreated NPC patients that contained no tumor cells. Using an immunofluorescent double-staining method, MIP-1alpha and MCP-1 were identified to be associated with macrophages, and IFN-gamma with T cells. Moreover, expression of CCR2 and CCR5, the receptors for these chemokines, was also detected in the tumor-infiltrating cells. These data indicate that the intense tumor infiltration by T cells and macrophages is a result of active recruitment. It seems possible that the intense infiltration of leukocytes in NPC tumor tissue is initiated by the activated tumor-reactive T cells. T cells migrate into the tumor tissue in an antigen-specific mode, and IFN-gamma secreted from these pioneer T cells activates tissue macrophages to express CC chemokines, especially MIP-1alpha and MCP-1, which consequently recruit more T cells and macrophages into the tumor tissue.

Increased production of interferon-gamma by tumour infiltrating T lymphocytes in nasopharyngeal carcinoma: indicative of an activated status

Undifferentiated nasopharyngeal carcinomas (UNPC) are characterised by an association with Epstein-Barr virus and an abundant lymphoid stroma. We studied the functional status of the infiltrating T cells in ten UNPC biopsies using an immunohistochemical approach. Twelve non-NPC biopsies were included as controls. Tumour cells of UNPC were positive for HLA class I (10/10) and II (8/10), LMP1 (3/10), and CD86 (6/10). Tumour infiltrating T cells (TILs) were detected with antibodies directed at CD3, CD4, and CD8, and shown to be comparable to that in the control biopsies. Although expression of CD28 was shown to be decreased in TILs, expression of CD25 and IFN-gamma at a relatively high percentage could be consistently detected in the UNPC biopsies. These data suggest that TILs in UNPC are in an activated status, and this T cell response is possibly directed at the tumour cells.

T lymphocyte activation in myasthenic thymoma

The functional and phenotypic characteristics of lymphocytes separated from myasthenic thymoma (Th-L) were compared with those of lymphocytes separated from non-thymomatous thymus associated with thymoma (NTh-L) of the same patients and NTh-L of myasthenia gravis (MG) patients without thymoma. We examined whether Th-L and NTh-L of MG patients reacted to interleukin-2 (IL-2) to develop lymphokine-activated killer (LAK) activity and/or cytolytic activity against K562 (natural killer (NK) activity), and the phenotypic changes in such cells during incubation. Ten MG patients with thymoma and six MG patients without thymoma, and four non-MG thymoma patients were included in this study. Th-L and NTh-L of MG patients reacted with IL-2 to develop LAK and NK activities. The LAK activity developed from Th-L was significantly higher than that from NTh-L, and the LAK activity developed from Th-L was as high as that from peripheral blood lymphocytes (PBL) in MG patients without thymoma. The proportions of CD3+ cells, CD4+/CD8- cells, and CD4-/CD8+ cells in Th-L of MG patients increased significantly during incubation. On the other hand, the proportion of CD4+/CD8+ cells in Th-L of MG patients decreased significantly. The proportions of CD4+/CD8- cells, CD4-/CD8+ cells, and CD4+/CD8+ cells in NTh-L of MG patients with and without thymoma exhibited no change during incubation. These findings suggest that CD4+/CD8+ Th-L of MG patients may have a higher potential to react to IL-2 than NTh-L, and that the former cells might develop LAK activity like that of PBL on maturation to CD4+/CD8- cells and CD4-/CD8+ cells. Our findings also suggested that Th-L might play an important role in the pathogenesis of MG with thymoma.

The significance of soluble interleukin-2 receptor in monitoring disease relapse in patients with nasopharyngeal cancer

BACKGROUND

Soluble interleukin-2 receptor alpha (sIL-2R alpha) is a well-known indicator of T-cell activation noted to be increasing in nasopharyngeal cancer. However, the significance of sIL-2R alpha in monitoring disease relapse is unclear. This study was initiated to address this issue.

METHODS

Serum of 56 patients with NPC, which underwent either primary, salvage, or palliative treatments, from 1992 to 1993 at the Cancer Center, Veterans General Hospital-Taipei, were collected from our serum bank. According to their disease status at the time of study, at least two years after last treatments, the 56 patients were divided into four groups. The remission group represented those in remission at the time of study (n = 24). The metastasis group represented those with distant metastasis present at the time of study (n = 17). The recurrence group represented those with locoregional recurrence present at the time of study (n = 11). The combined group represented those with locoregional recurrence as well as distant metastasis (n = 4). The seral sIL-2R alpha concentrations of the 56 NPC patients were determined with enzyme-linked immunoabsorbent assay. The combined group was excluded in our statistical analysis. We performed statistical analysis on the differences of paired serum sIL-2R alpha concentrations between different periods of the diseases. The first analysis was on the differences of sIL-2R alpha concentrations between diagnosis and post-radiotherapy periods for 13 out of 24 patients in the remission group and 7 out of 11 patients in the recurrence group. The second analysis was on the differences of sIL-2R alpha concentration between follow-up before detection-of-relapse and after detection-of-relapse for 5 out of 17 patients in the metastasis group and six out of 11 patients in the recurrence group.

RESULTS

The first statistical analysis revealed no significant differences of sIL-2R alpha concentrations for the remission group (P = 0.946) and the recurrence group (P = 0.156) between diagnosis and post-radiotherapy periods. The second statistical analysis revealed no significant differences of sIL-2R alpha concentrations between before and after detection-of-relapse for the recurrence group, neither (P = 0.438). The results for the metastasis group were different. The sIL-2R alpha concentrations were shown to increase after the detection of metastasis for the 5 paired samples from the metastasis group, although the Wilcoxon signed ranks test on the differences only showed borderline significance (P = 0.063).

CONCLUSIONS

Our findings show that sIL-2R alpha would be of no value in monitoring the development of locoregional recurrence but might be useful in monitoring distant metastasis. Although our current limited data did not provide strong support for the role of sIL-2R alpha in monitoring metastasis, it might be delineated in the future by collecting more data.

Limiting dilution analysis of proliferating and cytotoxic lymphocytes in the peripheral blood and tumours of oral cancer patients

Frequencies of proliferating and cytotoxic lymphocytes from the peripheral blood and tumour tissue of oral cancer patients and healthy individuals were monitored using limiting dilution analysis. Significantly lower precursor frequencies of proliferating lymphocytes were observed in the peripheral blood and tumour tissue of oral cancer patients. A high frequency of natural killer (NK) cells but low cytotoxic T lymphocytes (CTL) was observed in the peripheral blood compartment of oral cancer patients as compared to healthy individuals. A marked reduction in both NK and CTL frequencies in the tumour tissue compared to the peripheral blood was observed. In the tumour tissues, increased percentages of activated CD4+ lymphocytes as compared to CD8+ lymphocytes were observed. Our results suggest that impaired proliferative and cytotoxic potential of tumour infiltrating lymphocytes may play an important role in the escape of tumour cells from the immune system.

Myasthenia gravis induces the activation and maturation of lymphocytes in thymoma

The biological differences between lymphocytes separated from thymoma patients with myasthenia gravis (MG) and those separated from thymoma patients without MG was examined. We investigated whether lymphocytes in thymoma (Th-L) of patients with and without MG could react to interleukin-2 (IL-2) to develop cytolytic activity against K562 and lympho kine-activated killer (LAK) activity, and their phenotypic changes during incubation with IL-2. Sixteen thymoma patients who consisted of eight patients with MG and eight patients without MG were investigated. Th-L of all MG patients could react to IL-2 to develop LAK activity. Th-L of all of MG patients also developed cytolytic activity against K562 target cells. Cytolytic activity against K562 and LAK activity from Th-L of the MG patients were significantly higher than those from Th-L of the patients without MG (P < 0.01, P < 0.01). The proportions of CD3+ and CD4-/CD8+ cells of Th-L of MG patients increased significantly during the incubation period with IL-2 (P < 0.05, P < 0.05). The proportion of CD4+/CD8+ cells of Th-L of patients with MG decreased significantly (P < 0.05) during incubation with IL-2. On the other hand, there was no significant phenotypic change in Th-L of the patients without MG. These results indicate that MG induces the functional and phenotypic activation and functional and phenotypic maturation of Th-L.

Specific antitumor activity of tumor-infiltrating lymphocytes expanded first in a culture with both anti-CD3 monoclonal antibody and activated B cells and then in a culture with interleukin-2

In order to expand tumor-infiltrating lymphocytes (TIL) efficiently and in order to use them for immunotherapy, we utilized lipopolysaccharide-activated B cells (LPS blasts) as costimulatory-signal-providing cells in an in vitro culture system. TIL, prepared from subcutaneously inoculated B16 melanoma, failed to expand when cultured with anti-CD3 monoclonal antibody (mAb) alone followed by a low dose of interleukin(IL)-2. In contrast, such TIL did expand efficiently in culture with both anti-CD3 mAb and LPS blasts followed by culture with IL-2. These findings suggest that the presence of LPS blasts in the initial culture was essential for the cell expansion. The expansion of TIL was partially blocked by the addition of CTLA4 Ig, which is an inhibitor of costimulatory molecules such as CD80 and CD86, and was almost blocked by the addition of anti-(Fc receptor gamma II)mAb. These findings thus indicate that such molecules, in conjunction with the receptor on the LPS blasts, participate in the efficient expansion of TIL. The B16-derived TIL, which expanded in our culture system, were predominantly CD8+ T cells and showed a higher level of cytolytic activity against B16 melanoma than either lymphokine-activated killer cells or TIL cultured with a high dose of IL-2. In addition, the in vitro expanded B16-derived TIL produced interferon gamma, but not IL-4, in response to B16 melanoma. What is more important, the adoptive transfer of such TIL had a significant antitumor effect against pulmonary metastasis in B16 melanoma, even without the concurrent administration of IL-2. Collectively, our results thus indicate the therapeutic efficacy of the protocol presented here for antitumor immunotherapy with TIL.

Linear epitopes of the replication-activator protein of Epstein-Barr virus recognised by specific serum IgG in nasopharyngeal carcinoma

The linear antigenic epitopes of the Epstein-Barr virus replication activator protein (ZEBRA), recognised by specific serum IgG in nasopharyngeal carcinoma (NPC), were determined. This was achieved by synthesizing the entire amino acid sequence of ZEBRA as a set of 29, 22-residue peptides with an overlap of 14 amino acids. The ZEBRA peptides were tested in enzyme-linked immunosorbent assay (ELISA) for IgG binding in sera from 37 selected NPC patients who had IgG antibodies to the native ZEBRA protein. The most immunogenic epitope was peptide 1 at the amino-terminal end with 36 of the sera reactive against it. Further analysis of peptide 1, using the multipin peptide-scanning technique, defined a 10-amino-acid sequence FTPDPYQVPF, which was strongly bound by IgG. Two other regions of ZEBRA were also identified as immunodominant IgG epitopes, namely peptide 11 (amino acids 82-103) and peptide 19/20 (amino acids 146-175) with 8-13 of the NPC sera reactive against the peptides. The number of peptides reactive with individual NPC serum varies from 1 to 6 or more and there is some correlation between a greater number of peptide (at least 4) bound and a higher (at least 1:40) titre of serum IgA to viral capsid antigen. The immunodominant ZEBRA peptide 1 could be utilised in IgG ELISA for the detection of NPC.

The pattern of cytokine gene expression in freshly excised human metastatic melanoma suggests a state of reversible anergy of tumor-infiltrating lymphocytes

Expression of an extended panel of cytokine genes was investigated by reverse polymerase chain reaction (PCR) in 10 freshly excised melanoma metastases infiltrated by lymphocytes (TIL). cDNA encoding for CD3-delta and tyrosinase could be amplified in all samples, confirming the presence of T lymphocytes and melanoma cells. Cytokine genes possibly transcribed by both cell types, such as GM-CSF, IL-6 and IL-10 could be amplified from 5, 2 and 2 samples respectively. In contrast, IL-1 beta and TNF-alpha mRNA were never detectable, IL-1 alpha, IL-3 and IL-7 mRNA could be observed only in one case each. Transcripts encoding for TGF-beta 1 were observed in 8 samples, while TGF-beta 2 and 3 mRNA were detectable in only 2 specimens. mRNA encoding for cytokine genes typically transcribed by antigen-stimulated T lymphocytes, such as IL-2, IL-4 and IFN-gamma were rarely or never detectable (none, none and 1 of the samples respectively). In one case, where no cytokine gene transcription was detectable at the time of surgery, we addressed the question of the antigenicity of the tumor and of the functional competence of TIL. A primary tumor cell line was generated and cultured TIL were induced to transcribe IL-2 and IFN-gamma genes by incubation with the autologous irradiated tumor cell line, but not with autologous EBV-transformed cells. In these conditions, tumor-specific cytotoxic T lymphocytes (CTL) could be generated only after 3 weekly re-stimulations. In contrast, if autologous irradiated EBV-transformed cells were added to the cultures, specific CTL could be detected after one single tumor stimulation. Thus, signs of active responsiveness in terms of lymphokine gene mRNA are seldom detectable in melanoma metastases. Tumor-specific responses, however, including IL-2 and IFN-gamma gene expression and generation of CTL can be produced in vitro from specimens in which no cytokine gene mRNA is detectable ex vivo.

Characterization of lung squamous cell carcinoma-derived T-cell suppressive factor

BACKGROUND

The immunosuppressive state of a tumor-bearing patient is possibly mediated by tumor-derived factor. In this study, the authors characterized lung squamous cell carcinoma-derived immunosuppressive factor (LSCF).

METHODS

The immunosuppressive activity of QG56 (a lung squamous carcinoma cell line)-derived LSCF was evaluated by the effect of culture supernatant of QG56 on anti-CD3 monoclonal antibody-induced T-cell, response such as proliferation (3H-thymidine uptake), cytotoxicity (51Cr-releasing assay), and expression of cytokine mRNA (polymerase chain reaction). The LSCF was partially purified with an ion-exchange high-performance liquid chromatography (HPLC) and a gel-filtration HPLC.

RESULTS

The LSCF inhibited proliferation, cytotoxicity, and expression of cytokine mRNA of T-cells in a dose-dependent manner. It has a molecular weight of approximately 22 kd, and was sensitive to proteinase K, heating at 60 degrees C, and resistant to treatment with trypsin and pH 3 and 9. These properties appear to be similar to those of transforming growth factor-beta (TGF-beta). However, the activity of the LSCF was not abrogated by anti-TGF-beta sera, and the LSCF did not suppress the proliferation of TGF-beta-sensitive mink lung cells (Mv1Lu).

CONCLUSIONS

These data suggest that LSCF may be a novel tumor-derived immunosuppressive protein factor.

Infiltrating lymphocytes and accessory cells in nasopharyngeal carcinoma

The infiltrating lymphocytes (LCs) and accessory cells (ACs) including dendritic cells (DCs) and monocytes/macrophages in nasopharyngeal biopsies taken from 4 groups of nasopharyngeal carcinoma (NPC) patients were observed by using an immunostaining technique and the correlation of the results to the clinical manifestations and follow-up data was examined. The findings were as follows. (1) NPCs without lymph node metastasis always had marked infiltrating LCs and DCs as compared with those with lymph node(s) metastasis. (2) Advanced NPCs with lymph node(s) involvement (T1-4N1-3M0) and a rapid development of distant metastasis followed by death within 1 year after radiotherapy always showed fewer infiltrating LCs and DCs as compared with those with lymph node(s) metastasis (T1-4N1-3M0) and having longer than 5-year survival after radiotherapy. The amount of both LCs and ACs, especially DCs, infiltrating in NPC tissues appears to be an indicator of the activity of host immune defence mechanisms against cancer and influences the progression of the neoplasm as well as the prognosis.

Heterogeneity among human nasopharyngeal carcinoma cell lines for inflammatory cytokines mRNA expression levels

Using polymerase chain reaction (PCR), we confirmed the expression of interleukin-1 alpha (IL-1 alpha) by the human nasopharyngeal carcinoma (NPC) cell line C15 without contribution of either human IL-1 beta or mouse IL-1 alpha in the biological activity previously found in C15. However we showed that IL-1 alpha was not expressed in all NPCs. IL-1 beta and/or tumor necrosis factor (TNF)-alpha genes could also be activated, independently from the number of Epstein Barr Virus (EBV) copies harbored by the cells. Interestingly, the primary tumor C15 showed a profile of TNF-sensitive tumor while C17, C18 and C19 which were derived from metastasis have a typical profile of TNF-resistant cells. Furthermore, the inflammatory cytokines whose genes are classically induced by IL-1 and TNF were found expressed only in C17 and C19 suggesting another level of heterogeneity among NPCs.

Elevated expression of ICAM1 (CD54) and minimal expression of LFA3 (CD58) in epstein-barr-virus-positive nasopharyngeal carcinoma cells

Undifferentiated nasopharyngeal carcinoma (NPC) is a remarkable entity among human tumors because of its constant association with the Epstein-Barr virus (EBV). Malignant epithelial cells harbor the EBV genome and often express at least 2 species of latent EBV protein (EBNA1 and LMP1). Despite the massive presence of tumor-infiltrating lymphocytes, NPC cells obviously escape immune surveillance directed to EBV antigens. Previous investigations carried out on EBV-positive Burkitt lymphoma (BL) cells have shown that this fact may be partially accounted for by a lack of expression of ICAM1 (CD54) and LFA3 (CD58). ICAM1 and LFA3 have therefore been investigated in fresh NPC biopsies and transplanted NPCs. With only 1 exception out of 9 cases, NPC cells appear to express high levels of ICAM1 and low levels of LFA3. This is a complete inversion of the pattern observed in normal epithelial cells in vivo. Additional investigations will be required to determine to what extent these characteristics affect T-cell interactions with NPC cells, specially in the process of EBV-antigen recognition.