Expression of apoptotic regulatory molecules in renal cell carcinoma: elevated expression of Fas ligand

Current Advance of Immune Evasion Mechanisms and Emerging Immunotherapies in Renal Cell Carcinoma

Renal cell carcinoma is a highly heterogeneous cancer group, and the complex microenvironment of the tumor provides appropriate immune evasion opportunities. The molecular mechanism of immune escape in renal cell carcinoma is currently a hot issue, focusing primarily on the major complex of histocompatibility, immunosuppressive cells, their secreted immunosuppressive cytokines, and apoptosis molecule signal transduction. Immunotherapy is the best treatment option for patients with metastatic or advanced renal cell carcinoma and combination immunotherapy based on a variety of principles has shown promising prospects. Comprehensive and in-depth knowledge of the molecular mechanism of immune escape in renal cell carcinoma is of vital importance for the clinical implementation of effective therapies. The goal of this review is to address research into the mechanisms of immune escape in renal cell carcinoma and the use of the latest immunotherapy. In addition, we are all looking forward to the latest frontiers of experimental combination immunotherapy.

Significance of Fas expression alteration during tumor progression of renal cell carcinoma

BACKGROUND

In order to characterize the alteration of apoptotic regulatory molecule expression during tumor progression of renal cell carcinoma (RCC), we compared the expression between tumor and normal tissues, and evaluated the relationship of the expression in tumors with pathological and clinical characteristics.

METHODS

Competitive reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC) allowed the determination of Fas and bcl-2 mRNA and protein expression in surgically resected tumor and normal tissue of 50 RCC.

RESULTS

The mRNA expression of Fas and bcl-2 in RCC was significantly reduced compared to that in normal tissues. An IHC analysis was supportive of the RT-PCR results. In terms of relationships with pathological and clinical characteristics, the mRNA and protein expression of Fas in high-stage or high-grade tumors was significantly higher than that in low-stage or low-grade tumors. Moreover, a statistically poor prognosis was observed in tumor cases expressing a high amount of mRNA. In bcl-2 analysis, the mRNA and protein expression was significantly reduced in clear cell tumors compared to chromophobe cell tumors.

CONCLUSION

It is suggested that the reduced expression of Fas and bcl-2 in RCC compared with the expression in normal kidney is a prominent alteration of apoptotic regulatory molecules. The alteration of the up-regulated Fas expression might be characterized during the tumor progression stage. It is also suggested that the effect of alteration of bcl-2 expression might be minimal during the tumor progression stage because of the reduced expression in tumors of the clear cell type, which is the most dominant cell type in RCC.

Fas ligand expression in metastatic renal cell carcinoma during interleukin-2 based immunotherapy: no in vivo effect of Fas ligand tumor counterattack

PURPOSE

It has been hypothesized that tumor cells expressing Fas ligand (FasL) might be able to counterattack and neutralize tumor-infiltrating lymphocytes. We assessed the effect of FasL tumor counterattack on the clinical outcome of interleukin-2 (IL-2)-based immunotherapy in metastatic renal cell carcinoma.

EXPERIMENTAL DESIGN

Tumor core needle biopsies were obtained before IL-2-based immunotherapy in 86 patients and repeated within the first cycle in 57 patients. Tumor cells expressing FasL and intratumoral lymphocyte subsets expressing CD4, CD8, CD56, and CD57 were analyzed by immunohistochemistry.

RESULTS

At baseline, negative FasL staining in tumor cells was seen in 10 of 86 (12%) biopsies, whereas intense FasL staining was seen (a) in fewer than 10% of tumor cells in 26 (30%) biopsies; (b) in 11 to 50% of tumor cells in 25 (29%) biopsies; (c) in 51 to 90% of tumor cells in 18 (21%) biopsies; and (d) in >90% of tumor cells in 7 (8%) biopsies. On treatment, tumor FasL expression did not change from baseline levels. Moreover, tumor FasL expression was not correlated with objective response or survival whereas the absolute number of CD4(+), CD8(+), CD56(+), and CD57(+) cells per mm(2) tumor tissue at baseline was significantly higher in responding patients compared with nonresponding patients (P = 0.01, P = 0.008, P = 0.015, and P < 0.001, respectively). During the first course of immunotherapy, the absolute number of CD4(+), CD8(+), and CD57(+) cells per mm(2) tumor tissue was significantly higher in responding patients compared with nonresponding patients (P = 0.034, P < 0.001, and P < 0.001, respectively). However, no correlation was observed between the number of intratumoral lymphocytes and tumor FasL expression level.

CONCLUSION

These observations do not support the hypothesis that FasL tumor "counterattack" has an effect on the clinical outcome in metastatic renal cell carcinoma during IL-2-based immunotherapy.

Alteration of apoptotic regulatory molecules expression during carcinogenesis and tumor progression of renal cell carcinoma

BACKGROUND

In order to characterize the alteration of apoptotic regulatory molecule expressions during carcinogenesis and tumor progression of renal cell carcinoma (RCC), we compared the expressions between tumor and normal tissues, and evaluated the relationships between expressions in tumors with pathological and clinical characteristics.

METHODS

Reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC) allowed the determination of Fas, Fas ligand (FasL), and bcl-2 mRNA expressions in surgically resected tissues of 40 cases of RCC.

RESULTS

In comparing the mRNA expression incidence between tumor and normal tissues, RT-PCR analysis demonstrated that the Fas and bcl-2 incidence in tumors was significantly lower than that in normal tissues. An IHC analysis was supportive of the RT-PCR results that higher immunoreactivity was recognized in mRNA positive cases than in negative cases. With regard to relationships with pathological and clinical characteristics, FasL mRNA expression was recognized significantly more frequently in pT3a tumors than in pT1 tumors, and also more frequently in G2 tumors than in G1 tumors. A similar result was obtained by IHC analysis. Five patients died of cancer. Four of these patients had tumors which showed positive mRNA expression and a strong immunoreactivity of FasL.

CONCLUSION

It is suggested that the alteration of the down-regulated expression of Fas and bcl-2 might contribute to the carcinogenesis of RCC. It is also suggested that the alteration of up-regulated expression of FasL in tumors, which establishes the immune evasion mechanism in some malignancies, might be characterized during the tumor progression of RCC.

Fas ligand is up-regulated during the colorectal adenoma-carcinoma sequence

AIMS

Fas ligand (FasL) expression by cancer cells may mediate tumour immune privilege. The purpose of the present study was to investigate the timing and significance of FasL expression during the colorectal adenoma-carcinoma sequence.

METHODS

FasL expression was studied by immunohistochemistry in 170 formalin-fixed tissue sections representing the entire colorectal adenoma-carcinoma sequence. Reverse transcriptase polymerase chain reaction (RT-PCR) was used to search for FasL mRNA. Analysis of survival was performed in patients with carcinomas.

RESULTS

A significant positive linear correlation was found between FasL expression and tumour progression throughout the colorectal adenoma-carcinoma sequence (r(s)=0.677 P<0.001). A pattern of high FasL expression was detected in 19% of high grade adenomas, 40% of stage I-II, 67% of stage III and 70% of stage IV carcinomas. No significant differences were observed between FasL expression in the primary tumours and that in the corresponding liver metastases. The specificity of FasL expression was confirmed at RT-PCR. For stage I-II carcinomas, the 5 year survival was 90% in patients without, or with moderate, tumoural FasL expression compared with 60% in those with high tumoural FasL expression (P<0.05).

CONCLUSIONS

Our findings suggest that FasL expression may be involved in the development of colorectal cancer and its progression.

Fas (Apo-1/CD95) and Fas ligand interaction between gastric cancer cells and immune cells

BACKGROUND AND AIMS

It has been proposed that the expression of Fas ligand (Fas L) in tumors may play an important role in immune escape. This study was undertaken to test a 'counterattack' theory as a mechanism of immune escape in gastric carcinoma.

METHODS

Expression of Fas and Fas L was examined in the human gastric cancer cell lines using reverse transcription-polymerase chain reaction. Cytotoxicity was determined by the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assay. Apoptosis of target Jurkat cells was examined after coculture with the effector gastric cancer cells in vitro. Immunohistochemical staining was performed for the detection of Fas and FasL in tumor-infiltrating lymphocytes (TIL) and gastric cancer cells in vivo. Apoptosis was detected by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling (TUNEL) method in vitro and in vivo.

RESULTS

Fas and FasL mRNA were found to be differentially expressed in gastric cancer cell lines. The coculture experiment showed that apoptosis of Jurkat was induced by a FasL-overexpressing effector gastric cell SNU-484. In a Fas-expressing gastric cell SNU-638, Fas expression was upregulated by the treatment of gamma-interferon in a time- and concentration-dependent manner. SNU-638 treated with gamma-interferon was more sensitive to anti-Fas antibody-mediated cytotoxicity than was the control cell line, suggesting an increase of functional Fas in gastric cancer cells. The expression of FasL in gastric cancer cells and of Fas in apoptotic TIL was also detected in vivo.

CONCLUSION

The data indicate that the FasL expression of gastric cancer cells supports a 'counterattack theory' in gastric cancer cells and that the upregulation of Fas by IFN-gamma in SNU-638 may accelerate the apoptosis pathway through the Fas and FasL interaction between gastric cancer cells and immune cells. This result is supported by the expression of FasL in gastric cancer cells and apoptotic TIL in vivo. It is implicated that the different biological behaviors of gastric cancer cells could be at least in part explained by Fas and FasL interaction with immune cells.

Restricted gammadelta T-cell receptor repertoire in IgA nephropathy renal biopsies

BACKGROUND

We have previously reported that gammadelta T cells are involved in the progression of IgA nephropathy (IgAN) to renal failure. Our current study examined the diversity of the CDR3 region of the gammadelta T-cell receptor (TCR), and characterized the junctional sequences of gammadelta chain TCR transcripts from T cells infiltrating renal biopsies from patients with IgAN and in peripheral blood T cells (PBLs) from the same patients.

METHOD

RNA extracted from renal biopsies and PBLs of IgAN patients (N = 15) was transcribed and then amplified with primers specific for the four Vgamma and six Vdelta families. Controls were renal biopsies from thin basement membrane disease (N = 6) and a sample from a kidney with suppurative pyelonephritis. CDR3 length spectratyping and sequencing of TCR gammadelta-chain were used to analyze the diversity of CDR3 region of these receptors.

RESULTS

CDR3 spectratyping of gammadelta TCR junctional diversity demonstrated that TCR gammadelta chains (Vgamma1-3 and Vdelta1-3) expressed by T cells from PBLs of IgAN patients and the infected kidney showed highly diverse junctional lengths that were broadly distributed. In contrast, the junctional lengths of Vgamma1 (Vgamma2, 3, 4, 5, and 8 genes) and Vdelta1 transcripts in the T cells infiltrating kidneys with IgAN were much more restricted than those of PBLs. Renal biopsies from thin basement membrane disease demonstrated no significant signal for any Vgamma or Vdelta family. Sequence analysis of Vgamma1 and Vdelta1 transcripts from those patients with restricted CDR3 spectratyping profiles confirmed oligoclonal expansion of gammadelta T cells infiltrating the kidneys in those IgAN patients and also revealed recurrent junctional amino acid motifs in the TCR Vdelta1 chain in the kidney with IgAN.

CONCLUSION

The data show that gammadelta T cells infiltrating the kidneys of IgAN patients use a restricted subset of gammadelta T cells, indicating clonal expansion of individual gammadelta T cells in the kidneys with IgAN. The feature of recurrent junctional amino acid motifs in Vdelta1 T cells may indicate antigen-driven selection.

Identification of mRNAs expressed in tumor-infiltrating lymphocytes by a strategy for rapid and high throughput screening

Most gene expression methods often involve cumbersome steps or use expensive facilities. Additionally, some of the techniques, such as cDNA biochip, cannot define the sub-population of tissue from which the amplified cDNA was made. Here we present a rapid and high throughput screening method for analyzing the pattern of gene expression of tumor-infiltrating lymphocyte (TIL), which can minimize manipulations in cloned DNA sequencing and in bioinformatics. The pattern of TIL gene expression was studied in one ovarian cancer and one liver cancer. Our results have demonstrated that TILs have three different gene expression profiles: the first set of genes is involved in cell proliferation and mitogenic stimulation, such as c-myc and IL-8, LD78, MIP-1beta, insulin-induced protein and AH-receptor; the second set of genes includes those involved in attachment of lymphocytes to endothelium and extravasation into tumor tissues such as P-selectin ligand and integrin; and the third set, which includes genes such as the perforin, FAS ligand and granzyme B, is related to cytotoxic function to tumor cells. The patterns of TIL gene expression obtained from two specimens are marginally different and can be used in explaining the basis of molecular mechanisms regulating cellular interactions and cytotoxicity.

The status of Fas and Fas ligand expression can predict recurrence of hepatocellular carcinoma

The status of Fas and Fas ligand (Fas L) expression was investigated in this study for 103 hepatocellular carcinomas (HCC). We studied the expression of the following three factors, Fas and Fas L expression in carcinoma cells and Fas L expression in stromal mononuclear cells (defined as stromal Fas L index). Fas expression in HCC cells was significantly decreased in cases with poor differentiation (P < 0.0001) and of larger size (P = 0.0058). Fas L expression in carcinoma cells was observed exclusively in moderately or poorly differentiated cases. Furthermore, each factor had prognostic significance for disease-free survival (DFS) (P< 0.0001, P = 0.0222 and 0.0027 respectively). We then scored the results of each factor and defined the total score as 'Fas-Fas L risk score'. The P-value of the score for DFS was even lower than that of the clinical stage by multivariate analysis. These results suggest that the evaluation of Fas and Fas ligand expression potentially has a significant prognostic value for DFS of HCC patients, in addition to the clinical stage, and can be regarded as a new prognostic marker.