Anti-tumor reactivity of human lymphokine activated killer (LAK) cells against fresh and cultured preparations of renal cell cancer

Advances and Prospects in Cancer Immunotherapy

Cancer immunotherapy is a promising and effective treatment modality for patients with cancers. Cytokine, anticytokine, and antibody therapies appear to be effective in treating various forms of cancer. The human papillomavirus vaccine is protective for cervical cancer, and this discovery has paved the way to the development of cancer vaccines for other forms of virus-associated cancers such as liver cancer and Merkel cell carcinoma. Clinical trials have demonstrated that adoptive cell therapy using tumor-infiltrating lymphocytes can induce tumor regression in approximately 75% of metastatic melanoma patients, suggesting the possibility of using similar technique to effectively treat breast, lung, and renal cancers in the near future. Besides, genetically engineered T cells transduced with genes encoding specific T cell receptors and chimeric antigen receptors have been shown effective in the treatment of cancer patients. These studies suggest that combination therapies are superior choices in cancer immunotherapy for patients.

Biological effects and clinical significance of lenalidomide-induced tumour flare reaction in patients with chronic lymphocytic leukaemia: in vivo evidence of immune activation and antitumour response

Lenalidomide has demonstrated impressive antileukaemic effects in patients with chronic lymphocytic leukaemia (CLL). The mechanism(s) by which it mediates these effects remain unclear. Clinically, CLL patients treated with lenalidomide demonstrate an acute inflammatory reaction, the tumour flare reaction that is suggestive of an immune activation phenomenon. Samples from CLL patients treated with lenalidomide were used to evaluate its effect on the tumour cell and components of its microenvironment (immune cellular and cytokine). Lenalidomide was unable to directly induce apoptosis in CLL cells in vitro, however it modulated costimulatory (CD80, CD83, CD86) surface molecules on CLL cells in vitro and in vivo. Concurrently, we demonstrated that NK cell proliferation was induced by lenalidomide treatment in patients and correlated with clinical response. Cytokine analysis showed increase in levels of TNF-α post-lenalidomide treatment, consistent with acute inflammatory reaction. Furthermore, the basal cytokine profile (high IL-8, MIG, IP-10 and IL-4 levels and low IL-5, MIP1a, MIP1b, IL12/p70) was predictive of clinical response to lenalidomide. Collectively, our correlative studies provide further evidence that the antileukaemic effect of lenalidomide in CLL is mediated not only through modulation of the leukaemic clone but also through elements of the tumour microenvironment.

Cadherin-6: a new prognostic marker for renal cell carcinoma

PURPOSE

Cadherin-6, a new cell adhesion molecule of the cadherin family, is expressed in normal kidney and renal cell carcinoma. First results demonstrated that the expression of cadherin-6 in renal cell carcinoma may have prognostic value. We prospectively evaluated the importance of cadherin-6 in renal tumors in a large cohort of patients.

MATERIALS AND METHODS

A total of 216 patients with renal cell carcinoma who underwent tumor nephrectomy were evaluated for cadherin-6 expression by immunohistochemistry and immunoblotting. The expression pattern was correlated with known prognostic factors of renal cell carcinoma. Statistical analysis was performed by the Mann-Whitney U and Pearson chi-square tests. Multivariate analysis was performed by the proportional hazard Cox model.

RESULTS

Cadherin-6 expression in renal cell cancer correlated with known prognostic factors, such as pT stage (p = 0.03), pN stage (p = 0.001), histological growth pattern (p = 0.001), M stage (p = 0.06) and renal venous involvement (p = 0.019). There was no correlation with tumor grading (p = 0.74) or tumor size (p = 0.84). We developed a relative risk factor for renal cell cancer for our patients using the multivariate proportional hazard Cox model, which showed a statistically significant correlation with cadherin-6 expression (p = 0.028).

CONCLUSIONS

Cadherin-6, a new cell adhesion molecule of the cadherin family, is specifically expressed in the proximal tubule of normal kidneys and in renal cell cancer. In our prospective analysis the pattern of cadherin-6 expression correlated with known prognostic factors of renal cell cancer on univariate and multivariate analysis. Our data suggest that cadherin-6 is a new prognostic factor for renal cancer.

Chinese medicinal herbs inhibit growth of murine renal cell carcinoma

Tumors are known to produce factors suppressing immune functions. We previously showed that a murine renal cell carcinoma (Renca) suppressed macrophage function in vitro and that this suppression was abolished by co-incubation with extracts of two Chinese medicinal herbs. We now report that these phytochemicals are capable of inhibiting growth of Renca in vivo. BALB/c mice were transplanted intraperitoneally (IP) with 1-2 x 10(5) Renca cells. One day after tumor transplant, mice were randomized into two groups. One group was treated IP, daily for 10 days, with 100 microliters of phytochemicals containing 500 micrograms each of Astragalus membranaceus and Ligustrum lucidum, while the other group received saline as controls. A cure rate of 57% was obtained with these phytochemicals when the initial tumor load was 2 x 10(5), and 100% when the initial tumor load was 1 x 10(5). Additional experiments were performed to investigate the mechanisms involved in this protection. Splenic macrophages from tumor-bearing mice were shown to have depressed chemiluminescent oxidative burst activity, and this depression was restored with phytochemical treatment. Splenocytes from mice transplanted with Renca responded less favorably to interleukin-2 (IL-2) in generating lymphokine-activated killer (LAK) cells; again this depression was restored with phytochemical treatment. Our data suggest that these phytochemicals may have exerted their antitumor effects via augmentation of phagocyte and LAK cell activities.

Suppression of lymphokine-activated killer cell generation by tumor-infiltrating lymphocytes

A functional analysis of tumor-infiltrating lymphocytes (TILs) from renal cell carcinoma (RCC) and malignant melanoma was performed. TILs were expanded in recombinant interleukin-2 (50 U/ml) in Iscoves medium. Phenotypic and functional (cytolytic vs regulatory) analyses were carried out with the fresh and expanded TIL populations after 4 weeks in culture. Only one TIL population from an RCC case (out of six cases studied) was CD8+ and demonstrated MHC class I-restricted tumor-specific cytotoxicity against the autologous RCC target. TIL populations from the other five cases became predominantly CD4+ and they neither killed the respective autologous tumor cells nor killed the NK-sensitive target K-562 cells. When studied for other functions, two CD4+ TIL populations were found to suppress the lymphokine-activated killer cell response by peripheral blood lymphocytes (PBL) in coculture. Of these two, a TIL population from an RCC case (MJ TIL) was used to study the cellular and molecular mechanisms of suppression. The MJ TIL synthesized a supernatant factor that blocked activation of resting PBL as measured by the induction of high-affinity IL-2 receptor (IL-2R) when stimulated by phytohemagglutinin but did not down-regulate the fully expressed IL-2R on activated T cells. The suppression of high-affinity IL-2R induction on T cells did not result from tumor necrosis factor-alpha and beta or from transforming growth factor-beta as these cytokines were not detected in the cell-free supernatant from the MJ TIL culture. The supernatant factor also suppressed IL-2-mediated enhancement of cytotoxicity by natural killer (NK) cells without demonstrating direct toxic effect on the NK cells. Thus, when TIL are used for adoptive immunocytotherapy, it may be useful to fully characterize them functionally, in vitro.

Induction of cytotoxicity of the renal hilar lymph nodes by pedal subcutaneous administration of interleukin-2 in patients with renal cancer

The authors attempted to increase the cytotoxicity of the renal hilar lymph nodes in ten patients with renal cell carcinoma by administration of recombinant interleukin-2 (IL-2) into the subcutaneous tissue of the instep. A total of 5000 to 21,000 units was given over 3 to 12 preoperative days. Mononuclear cells separated from the lymph nodes excised from the renal hilum at surgery served as the effector cells. Fresh autologous tumor cells and three cultured cell lines, K562, Raji, and ACHN, served as the target cells. Cytotoxicity was measured by a chromium-releasing assay. The results showed that the mononuclear cells from the lymph nodes of the patients given IL-2 became cytotoxic to all target cells. Surface markers of lymphocytes in the lymph nodes were unchanged. Peripheral blood lymphocytes showed increased cytotoxicity only against Raji cells. Adverse effects were mild or moderate and included local redness, high fever, liver dysfunction, and toxic erythema.

TIL from renal-cell carcinoma: restimulation with tumor influences proliferation and cytolytic activity

TIL were cultured from human renal-cell carcinoma (RCC) in 1,000 U/ml rIL2 and restimulated with autologous tumor in efforts to establish which conditions would best expand the number of lymphocytes cytotoxic for autologous tumor. Greater cell yields resulted from multiple restimulations of TIL with autologous tumor. In most instances, these TIL lysed autologous tumor better than TIL grown in rIL2 alone. Enhanced proliferation was seen also after restimulation of TIL with allogeneic RCC as well as with tumor cells of non-renal origin. Although in some instances lysis of autologous tumor appeared to be specific, restimulation with autologous tumor did not consistently result in the generation of specific cytolytic T cells. Attempts to culture more specific cytolytic T cells by using 50 U/ml rIL2 were successful in expanding TIL with enhanced lytic activity; however, this activity was not specific for autologous tumor. The phenotype of the tumor-restimulated TIL generally did not change. In most of the TIL cultures, CD3+CD4+ cells were predominant with low numbers of CD3+Leu19+ cells and minimal numbers of CD3-Leu19+ cells. Thus, the cytotoxic response to tumor was mediated by T cells and not NK cells. Overall, our data indicate that restimulation of TIL with autologous tumor may be beneficial for growing larger numbers of cells which have increased lytic activity and for prolonging the presence of lytic activity among the expanded TIL.