Interleukin-15 gene therapy and the mammalian target of rapamycin inhibitor everolimus inhibit the growth of metastatic breast cancer

Neoadjuvant everolimus plus letrozole versus fluorouracil, epirubicin and cyclophosphamide for ER-positive, HER2-negative breast cancer: a randomized pilot trial

Background

Here we evaluated the feasibility, efficacy, tolerability, and treatment-mediated immune modulation of neoadjuvant everolimus plus letrozole versus chemotherapy in treating postmenopausal patients with ER-positive, HER2-negative breast cancer.

Methods

Postmenopausal women with ER-positive, HER2-negative breast cancer who had a primary tumor > 2 cm or positive axillary lymph node(s) proofed by biopsy were randomly (1,1) enrolled to receive neoadjuvant everolimus plus letrozole for 18 weeks or fluorouracil, epirubicin plus cyclophosphamide (FEC) for 6 cycles before surgery. Primary outcome was feasibility of the trial. Secondary outcome included ultrasound response rate, pathological complete response rate, breast-conserving surgery rate, toxicities, treatment-mediated immune modulation and biomarkers.

Results

Forty patients were randomized. Completion rate was 90.0% in the neoadjuvant endocrine therapy (NET) arm but 70.0% in the neoadjuvant chemotherapy (NAC) arm. The ultrasound response rate was 65.0% in NET arm and 40.0% in FEC arm, respectively. In terms of the adverse events, clearly favored NET arm. Everolimus plus letrozole increased the ratio of peripheral Tregs to CD4⁺ T cells and tumor PD-L1 expression, and decreased Ki67 index and tumor-infiltrating Tregs, and patients with a greater increase of tumor-specific CTLs showed more sensitive to NET.

Conclusion

This pilot trial showed that neoadjuvant everolimus plus letrozole might achieve a favorable ultrasound response rate with low toxicities in treating postmenopausal ER-positive, HER2-negative breast cancer patients. Everolimus plus letrozole might have positive antitumoral immunity effects. Further large randomized controlled trials are needed to confirm our findings.

Trail registration

A Trial of Neoadjuvant Everolimus Plus Letrozole Versus FEC in Women With ER-positive, HER2-negative Breast Cancer, registered on 07/04/2016 and first posted on 18/04/2016, NCT02742051.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08612-y.

Chronic everolimus treatment of high-fat diet mice leads to a reduction in obesity but impaired glucose tolerance

Everolimus, which inhibits mTOR kinase activity and is clinically used in graft rejection treatment, may have a two‐sided influence on metabolic syndrome; its role in obesity and hyperglycemic in animals and humans, however, has been explored insufficiently. This study further determined how continual everolimus treatment affects glucose homeostasis and body weight control in C57BL6/J mice with obesity. An obesity mouse model was developed by administering a high‐fat diet (HFD) to C57BL6/J mice over 12 weeks. The experimental group, while continuing their HFD consumption, were administered everolimus daily for 8 weeks. Metabolic parameters, glucose tolerance, fatty liver score, endocrine profile, insulin sensitivity index (ISI), insulin resistance (IR) index, and Akt phosphorylation, GLUT4, TNF‐α, and IL‐1 levels were measured in vivo. Compared with the control group, the everolimus group gained less body weight and had smaller adipocytes and lower fat pad weight; triglyceride (serum and hepatic), patatin‐like phospholipase domain‐containing 3, and fatty acid synthase levels; fatty liver scores; and glucose tolerance test values—all despite consuming more food. However, the everolimus group exhibited decreased ISI and muscle Akt phosphorylation and GLUT4 expression as well as impaired glucose tolerance and serum TNF‐α and IL‐1β levels—even when insulin levels were high. In conclusion, continual everolimus treatment may lead to diabetes with glucose intolerance and IR.

Deficiency of IL-18 Aggravates Esophageal Carcinoma Through Inhibiting IFN-γ Production by CD8+T Cells and NK Cells

To investigate the potential role of interleukin-18 (IL-18) in immunomodulation during tumorigenesis of esophageal carcinoma and elucidate the underlying molecular mechanism, we employed IL-18 knockout mice for this purpose. Carcinogen 4-nitroquinoline 1-oxide (4NQO) was administrated in drinking water to induce occurrence of esophageal squamous cell carcinoma (ESCC). T cell activation as indicated by the surface CD molecules was analyzed with flow cytometry. The serous content of interferon-γ (IFN-γ) along with other cytokines was determined by inflammatory human cytokine cytometric bead array. The cytotoxicity assay was performed by co-culture of tumor cells with immune cells and relative cell viability was determined by lactate dehydrogenase (LDH) assay. Apoptotic cells were stained with Annexin-V/propidium iodide (PI) and analyzed by flow cytometry. Cell proliferation was measured with Cell Counting Kit-8 (CCK-8) assay. Our data demonstrated that deficiency of IL-18 promoted the progression and development of 4NQO-induced ESCC. Loss of IL-18 suppressed the activation of T cells in the esophagus. Deficiency of IL-18 inhibited the IFN-γ production by CD8⁺ T cells and natural killer (NK) cells. Absence of IL-18 inhibited the cytotoxicity of CD8⁺ T cells and NK cell in vitro. Moreover, deficiency of IL-18 promoted the apoptosis of CD8⁺ T cells and inhibited the proliferation of CD8⁺ T cells in vitro. Our data elucidated the immunomodulatory role of IL-18 during tumorigenesis of ESCC, whose deficiency compromised antitumor immunity and contributed to immune escape of esophageal carcinoma. Our results also indicated the therapeutic potential of exogenous IL-18 against ESCC, which warrants further investigations.

The next generation of PI3K-Akt-mTOR pathway inhibitors in breast cancer cohorts

The PI3K/Akt/mTOR pathway plays a role in various oncogenic processes in breast cancer and key pathway aberrations have been identified which drive the different molecular subtypes. Early drugs developed targeting this pathway produced some clinical success but were hampered by pharmacokinetics, tolerability and efficacy problems. This created a need for new PI3K pathway-inhibiting drugs, which would produce more robust results allowing incorporation into treatment regimens for breast cancer patients. In this review, the most promising candidates from the new generation of PI3K-pathway inhibitors is explored, presenting evidence from preclinical and early clinical research, as well as ongoing trials utilising these drugs in breast cancer cohorts. The problems hindering the development of drugs targeting the PI3K pathway are examined, which have created problems for their use as monotherapies. PI3K pathway inhibitor combinations therefore remains a dynamic research area, and their role in combination with immunotherapies and epigenetic therapies is also inspected.

Neoadjuvant everolimus plus letrozole versus fluorouracil, epirubicin and cyclophosphamide for ER-positive, HER2-negative breast cancer: study protocol for a randomized pilot trial

Background

The response to neoadjuvant chemotherapy (NAC) varies by estrogen receptor (ER) and human epidermal growth factor receptor 2 (HER2) statuses, with responses being lower in ER-positive, HER2-negative tumors as compared with ER-negative, HER2-positive or triple-negative tumors. Neoadjuvant endocrine therapy (NET) is an attractive alternative to NAC for ER-positive, HER2-negative cancer. However, a prior trial comparing NET with standard NAC in ER-positive tumor showed that the difference of response was not significant. Studies demonstrated that the mTOR inhibitor everolimus could sensitize breast tumors to endocrine therapy. A pilot open-label, randomized trial has been designed to evaluate the feasibility, efficacy and tolerability of neoadjuvant everolimus plus letrozole versus NAC in treating postmenopausal women with ER-positive, HER2-negative breast cancer.

Methods

Forty postmenopausal women with non-metastatic ER-positive, HER2-negative invasive breast cancer with a primary tumor > 2 cm or positive axillary lymph node(s) proved by biopsy will be randomly (1:1) enrolled from Sun Yat-Sen Memorial Hospital to receive neoadjuvant everolimus plus letrozole for 18 weeks or fluorouracil, epirubicin plus cyclophosphamide (FEC) for six cycles before surgery. Primary outcome is the feasibility of the trial. Secondary outcome measures include ultrasound response rate, pathological complete response rate, breast-conserving surgery rate, toxicities, and changes in the percentages of peripheral blood CD4⁺ T cells, CD8⁺ T cells, T helper cells, regulatory T cells, and NK cells.

Discussion

This is the first study to determine the feasibility, efficacy and tolerability of head-to-head neoadjuvant everolimus plus letrozole versus neoadjuvant FEC in treating postmenopausal women with ER-positive, HER2-negative breast cancer. The trial will provide evidence to assess the feasibility of a future multicenter, randomized controlled trial, and will provide valuable clinical data of the immunoregulatory effect of everolimus in breast cancer.

Trial registration

ClinicalTrials.gov registry, ID: NCT02742051. Registered on 7 April 2016.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2228-5) contains supplementary material, which is available to authorized users.

Biological Response Modifier in Cancer Immunotherapy

Biological response modifiers (BRMs) emerge as a lay of new compounds or approaches used in improving cancer immunotherapy. Evidences highlight that cytokines, Toll-like receptor (TLR) signaling, and noncoding RNAs are of crucial roles in modulating antitumor immune response and cancer-related chronic inflammation, and BRMs based on them have been explored. In particular, besides some cytokines like IFN-α and IL-2, several Toll-like receptor (TLR) agonists like BCG, MPL, and imiquimod are also licensed to be used in patients with several malignancies nowadays, and the first artificial small noncoding RNA (microRNA) mimic, MXR34, has entered phase I clinical study against liver cancer, implying their potential application in cancer therapy. According to amounts of original data, this chapter will review the regulatory roles of TLR signaling, some noncoding RNAs, and several key cytokines in cancer and cancer-related immune response, as well as the clinical cases in cancer therapy based on them.

Mechanisms and applications of interleukins in cancer immunotherapy

Over the past years, advances in cancer immunotherapy have resulted in innovative and novel approaches in molecular cancer diagnostics and cancer therapeutic procedures. However, due to tumor heterogeneity and inter-tumoral discrepancy in tumor immunity, the clinical benefits are quite restricted. The goal of this review is to evaluate the major cytokines-interleukins involved in cancer immunotherapy and project their basic biochemical and clinical applications. Emphasis will be given to new cytokines in pre-clinical development, and potential directions for future investigation using cytokines. Furthermore, current interleukin-based approaches and clinical trial data from combination cancer immunotherapies will also be discussed. It appears that continuously increasing comprehension of cytokine-induced effects, cancer stemness, immunoediting, immune-surveillance as well as understanding of molecular interactions emerging in the tumor microenvironment and involving microRNAs, autophagy, epithelial-mesenchymal transition (EMT), inflammation, and DNA methylation processes may hold much promise in improving anti-tumor immunity. To this end, the emerging in-depth knowledge supports further studies on optimal synergistic combinations and additional adjuvant therapies to realize the full potential of cytokines as immunotherapeutic agents.

Mechanisms and applications of interleukins in cancer immunotherapy

Over the past years, advances in cancer immunotherapy have resulted in innovative and novel approaches in molecular cancer diagnostics and cancer therapeutic procedures. However, due to tumor heterogeneity and inter-tumoral discrepancy in tumor immunity, the clinical benefits are quite restricted. The goal of this review is to evaluate the major cytokines-interleukins involved in cancer immunotherapy and project their basic biochemical and clinical applications. Emphasis will be given to new cytokines in pre-clinical development, and potential directions for future investigation using cytokines. Furthermore, current interleukin-based approaches and clinical trial data from combination cancer immunotherapies will also be discussed. It appears that continuously increasing comprehension of cytokine-induced effects, cancer stemness, immunoediting, immune-surveillance as well as understanding of molecular interactions emerging in the tumor microenvironment and involving microRNAs, autophagy, epithelial-mesenchymal transition (EMT), inflammation, and DNA methylation processes may hold much promise in improving anti-tumor immunity. To this end, the emerging in-depth knowledge supports further studies on optimal synergistic combinations and additional adjuvant therapies to realize the full potential of cytokines as immunotherapeutic agents.

Interleukin-7 and interleukin-15 for cancer

Interleukin 7 and 15 are considered powerful pro-inflammatory cytokines, they have the ability to destabilize chromosomes and induce tumorigenesis. Additionally, they can control malignancy proliferation by influencing the tumor microenvironment and immune system. Immunotherapy has been proposed as a treatment modality for malignancy for over a decade; the exact mechanisms of action and pathways are still under investigation. Interleukin 7 and 15 have been extensively investigated in hematological malignancies since their mode of action influences the stimulation of the immune system in a more direct way than other malignancies such as lung, melanoma, and breast, renal and colorectal cancer.

Interleukin-15: new kid on the block for antitumor combination therapy

Interleukin (IL)-15 is one of the most promising molecules to be used in antitumor immune therapy, as it is able to stimulate the main killer cells of both the innate and adaptive immune system. Although this cytokine can be used as a stand-alone immunotherapeutic agent, IL-15 will probably be most efficient in combination with other strategies to overcome high tumor burden, immune suppression of the tumor microenvironment and/or the short half-life of IL-15. In this review, we will discuss the combination strategies with IL-15 that have been tested to date in different animal tumor models, which include chemotherapy, other immunostimulatory cytokines, targeted therapy, adoptive cell transfer and gene therapy. In addition, we give an overview of IL-15 combination therapies that are currently tested in clinical studies to treat patients with hematological or advanced solid tumors.

Immunostimulatory activity of lifespan-extending agents

During the past two decades, several interventions have been shown to increase the healthy lifespan of model organisms as evolutionarily distant from each other as yeast, worms, flies and mammals. These anti-aging maneuvers include (but are not limited to) cycles of caloric restriction, physical exercise as well as the administration of multiple, chemically unrelated agents, such as resveratrol, spermidine and various rapamycin-like compounds collectively known as rapalogs. Most, if not all, lifespan-extending agents promote macroautophagy (hereafter referred to as autophagy), an evolutionarily old mechanism that contributes to the maintenance of intracellular homeostasis and plays a critical role in the adaptive response of cells to stress. In line with this notion, the activation of autophagy appears to mediate significant anti-ageing effects in several organisms, including mice. Here, we focus on rapalogs to discuss the possibility that part of the beneficial activity of lifespan-extending agents stems from their ability to exert immunostimulatory effects. Accumulating evidence indicates indeed that the immune system can recognize and eliminate not only cells that are prone to undergo malignant transformation, but also senescent cells, thus playing a significant role in the control of organismal aging. In addition, it has recently become clear that rapamycin and other rapalogs, which for a long time have been viewed (and used in the clinic) as pure immunosuppressants, can mediate robust immunostimulatory functions, at least in some circumstances.