IL-12 augments antitumor responses to cycled chemotherapy. J Immunother. 2015;38:137-144. [PMID: 25839439 DOI: 10.1097/cji.0000000000000074]

Activation of the TGF-β Pathway Enhances the Efficacy of Platinum-Based Chemotherapy in Small Cell Lung Cancer Patients

Background

Platinum-based chemotherapy is the first choice of treatment for patients diagnosed with small lung cell cancer (SCLC). However, many patients exhibit resistance to it. Therefore, it is imperative to further investigate a prognostic biomarker indicating sensitivity to this therapy.

Methods

We collected and performed RNA sequencing on 45 SCLC samples from the Zhujiang Hospital (Local-SCLC). In addition, we used a public cohort from George et al. as a validation cohort (George-SCLC). The transforming growth factor β signaling pathway (TGFB) activation status was determined according to the related ssGSEA score. We analyzed immune cell ratios, pathway activation scores, and immune-related genes in SCLC patients to further elucidate the potential mechanisms.

Results

A high activation status of the TGFB pathway was associated with improved prognosis in SCLC patients receiving platinum-based chemotherapy (Local-SCLC: HR = 0.0238, (95% CI, 0.13-0.84), p = 0.0238; George-SCLC: HR = 0.0315, (95% CI, 0.28-0.98), p = 0.0315). Immune infiltration analysis showed that the TGFB-HIGH group had more M1 macrophages and Th1 cells, whilst fewer M2 macrophages, Th2 cells, and Treg cells were found in the Local-SCLC cohort. Mechanistic analysis showed that the TGBF-HIGH group was upregulated in STING-mediated immunity, apoptosis, and cell cycle arrest, as well as being downregulated in the process of DNA damage repair.

Conclusions

SCLC patients exhibiting a high activation status of the TGFB pathway demonstrate an improved prognosis with platinum-based chemotherapy. The potential underlying mechanism may be related to antitumor immune enhancement and DNA damage repair inhibition.

Intratumoral expression of IL-12 from lentiviral or RNA vectors acts synergistically with TLR4 agonist (GLA) to generate anti-tumor immunological memory

Systemic interleukin-12 (IL12) anti-tumor therapy is highly potent but has had limited utility in the clinic due to severe toxicity. Here, we present two IL12-expressing vector platforms, both of which can overcome the deficiencies of previous systemic IL12 therapies: 1) an integrating lentiviral vector, and 2) a self-replicating messenger RNA formulated with polyethyleneimine. Intratumoral administration of either IL12 vector platform resulted in recruitment of immune cells, including effector T cells and dendritic cells, and the complete remission of established tumors in multiple murine models. Furthermore, concurrent intratumoral administration of the synthetic TLR4 agonist glucopyranosyl lipid A formulated in a stable emulsion (GLA-SE) induced systemic memory T cell responses that mediated complete protection against tumor rechallenge in all survivor mice (8/8 rechallenged mice), whereas only 2/6 total rechallenged mice treated with intratrumoral IL12 monotherapy rejected the rechallenge. Taken together, expression of vectorized IL12 in combination with a TLR4 agonist represents a varied approach to broaden the applicability of intratumoral immune therapies of solid tumors.

A Review of Clinical and Preclinical Studies on Therapeutic Strategies Using Interleukin-12 in Cancer Therapy and the Protective Role of Interleukin-12 in Hematological Recovery in Chemoradiotherapy

Interleukin-12 (IL-12), a heterodimeric glycoprotein with α and β subunits covalently bonded with a disulfide bond, is a potent anticancer agent. Its action is accomplished through a linkage of the adaptive and innate immune responses. IL-12 can promote the recovery of the hematopoietic system after cancer chemoradiotherapy by stimulating the physiological processes of stem cells, including cell proliferation and differentiation, reconstitution of hematopoietic function, and peripheral blood count recovery. We review therapeutic strategies using IL-12 in clinical studies, including single-agent and combination strategies in hematological tumors and solid tumors, and studies on the protective effects of IL-12 in chemoradiotherapy. This review highlights promising therapeutic strategies based on the anticancer role of IL-12 and the potential protective effects of IL-12 for cancer patients receiving chemoradiotherapy.

Tumor reductive therapies and antitumor immunity

Tumor reductive therapy is to reduce tumor burden through direct killing of tumor cells. So far, there is no report on the connection between antitumor immunity and tumor reductive therapies. In the last few years, a new category of cancer treatment, immunotherapy, emerged and they are categorized separately from classic cytotoxic treatments (chemo and radiation therapy). The most prominent examples include cellular therapies (LAK and CAR-T) and immune checkpoint inhibitors (anti-PD-1 and CTLA-4). Recent advances in clinical immunotherapy and our understanding of the mechanism behind them revealed that these therapies have a closer relationship with classic cancer treatments than we thought. In many cases, the effectiveness of classic therapies is heavily influenced by the status of the underlying antitumor-immunity. On the other hand, immunotherapies have shown better outcome when combined with tumor reductive therapies, not only due to the combined effects of tumor killing by each therapy but also because of a synergy between the two. Many clinical observations can be explained once we start to look at these classic therapies from an immunity standpoint. We have seen their direct effect on tumor antigen in vivo that they impact antitumor immunity more than we have realized. In turn, antitumor immunity contributes to tumor control and destruction as well. This review will take the immunological view of the classic therapies and summarize historical as well as recent findings in animal and clinical studies to make the argument that most of the cancer treatments exert their ultimate efficacy through antitumor immunity.

Study of recombinant human interleukin-12 for treatment of complications after radiotherapy for tumor patients

AIM

To evaluate the treatment effects of recombinant human interleukin-12 (rhIL-12) on radiotherapy complications, such as severe myelosuppression or pancytopenia, the decline or imbalance of immune function, etc.

METHODS

The patients received high-dose and short-course precise radiotherapy, such as Cyber knife and image-guided radiotherapy (IGRT), which can cause myelosuppression or pancytopenia and immune function decline within a short time. One-hundred subjects were enrolled in the study, and 50 were randomized to a treatment group which used rhIL-12 and 50 were randomized to a control group which used symptomatic and supportive therapy after radiotherapy. The 50 subjects in the treatment group were further divided into five subgroups and intervened with rhIL-12 at a dose of 50, 100, 150, 200 or 250 ng/kg respectively. The dose-effect relationship was observed.

RESULTS

RhIL-12 significantly attenuated the decrease of peripheral blood cells in the treatment group, and immune function was improved after treatment. Due to the different radiation doses, there was a fluctuation within 12 h after treatment but mostly showing an increasing trend. As to the clinical manifestations, 2 patients in the 250 ng/kg subgroup showed low fever after administration, 1 patient in the 200 ng/kg subgroup and 2 patients in the 250 ng/kg subgroup showed mild impairment of liver function during the observation period.

CONCLUSION

RhIL-12 has effective therapeutic and protective effects on complications following radiotherapy, such as the decline of blood cells, myelosuppression and the decline or imbalance of immune function, which indicated good prospects for development and application.

In situ vaccine, immunological memory and cancer cure

As surgery is able to remove primary tumors and limit metastases, the major challenge in cancer management is the prevention of post-resection recurrence and metastases. From the immune point of view, tumor resection removes the supply of tumor antigens that maintain an active concomitant antitumor immunity elicited by the primary tumor, and may also signal for deposition of immunological memory against future metastases. However, the natural course of this antitumor immunity in many cancer patients following complete tumor resection may not be favorable because protection is often lost after 1-3 years. Recent studies suggest that chemotherapy is able to activate this pre-existing antitumor immunity, and tumor resection following immune activation may lead to higher levels of immunological memory against future tumor antigens (in the form of metastases). Interleukin-12 added to chemotherapy mimics the function of a vaccine adjuvant in that it helps to enhance the antitumor immunity activated by chemotherapy and leaves a much stronger antitumor immune memory. This finding, when applied to cancer management, may help to maintain a strong and long lasting antitumor immunity following complete tumor resection, thus eliminating post-surgery recurrence and metastases.

Functional Changes of Dendritic Cells in C6 Glioma-Bearing Rats That Underwent Combined Argon-Helium Cryotherapy and IL-12 Treatment

OBJECTIVE

The aim of this study was to explore changes in tumor tissues of glioma-bearing rats that underwent argon-helium cryoablation as well as changes in antitumor immunity before and after combined interleukin 12 treatment.

METHODS

Two hundred sixty Wistar rats were randomly divided into a blank control group, intravenous injection interleukin-12 group, cryotherapy group, and cryotherapy + intravenous injection group. C6 glioma cells proliferated in vitro were implanted subcutaneously on the backs of rats to establish C6 glioma-bearing animal models. Each group underwent the corresponding treatments, and morphological changes in tumor tissues were examined using hematoxylin-eosin staining. CD11c staining was examined using immunohistochemistry, and differences in dendritic cells and T-cell subsets before and after treatment were analyzed using flow cytometry.

RESULTS

The control group showed no statistical changes in terms of tumor tissue morphology and cellular immunity, cryotherapy group, and cryotherapy + intravenous injection group, among which the count for the cryotherapy + intravenous injection group was significantly higher than those of all other groups. In the argon-helium cryotherapy group, tumor cells were damaged and dendritic cell markers were positive. The number of CD11c+ and CD86+ cells increased significantly after the operation as did the cytokine interferon-γ level (P < .01), suggesting a shift toward Th1-type immunity.

CONCLUSION

Combined treatment of argon-helium cryoablation and interleukin 12 for gliomas not only effectively injured tumor tissues but also boosted immune function and increased antitumor ability. Therefore, this approach is a promising treatment measure for brain gliomas.