Inhibition of IRAK1/4 enhances the antitumor effect of lenvatinib in anaplastic thyroid cancer cells

Suppression of TLR signaling by IRAK-1 and -4 dual inhibitor decreases TPF-resistance-induced pro-oncogenic effects in HNSCC

Combination of docetaxel, cisplatin and 5-FU, known as TPF, is an FDA-approved treatment for head and neck squamous cell carcinoma (HNSCC). Acquired chemo-resistance to TPF, a primary reason for non-responsiveness to the treatment and relapse of tumor is a major concern for treatment failure, especially in elder patients. In this study, we investigated the role of Interleukin-1 receptor-associated kinases (IRAK) mediated Toll-like receptor (TLR)-signaling in chemo-resistance using a cell line-based in-vitro TPF-resistant HNSCC model of laryngeal origin. TPF chemo-resistant state showed over-expression and phosphorylation of the active downstream kinases IRAK-1 and IRAK-4 along with enhanced proliferative potential, survival, stemness and metastatic capability as compared to the parent cell line. Pharmacological inhibition of IRAK-1 and -4 had a cytostatic effect on chemo-resistant cells and re-sensitized them to chemotherapy. The treatment also decreased the pro-oncogenic effects of the chemo-resistant cells. Our study provides insights into the pro-oncogenic role of amplified IRAK-1 and-4 mediated TLR signaling in TPF-resistant HNSCC. Pharmacological inhibition of IRAK-1 and-4 signaling is a promising therapeutic strategy for TPF-resistant HNSCC. It can also be used as a combination therapy or a chemo-drug sparing regimen in HNSCC.

Epigenetic and transcriptional regulation of innate immunity in cancer

Innate immune cells participate in the detection of tumor cells via complex signaling pathways mediated by pattern-recognition receptors, such as Toll-like receptors (TLR) and NOD-like receptors (NLR). These pathways are finely tuned via multiple mechanisms, including epigenetic regulation. It is well established that hematopoietic progenitors generate innate immune cells that can regulate cancer cell behavior, and the disruption of normal hematopoiesis in pathologic states may lead to altered immunity and the development of cancer. In this review, we discuss the epigenetic and transcriptional mechanisms that underlie the initiation and amplification of innate immune signaling in cancer. We also discuss new targeting possibilities for cancer control that exploit innate immune cells and signaling molecules, potentially heralding the next generation of immunotherapy.

IRAK1 and IRAK4 as emerging therapeutic targets in hematologic malignancies

PURPOSE OF REVIEW

Cell intrinsic and extrinsic perturbations to inflammatory signaling pathways are a hallmark of development and progression of hematologic malignancies. The interleukin 1 receptor-associated kinases (IRAKs) are a family of related signaling intermediates (IRAK1, IRAK2, IRAK3, IRAK4) that operate at the nexus of multiple inflammatory pathways implicated in the hematologic malignancies. In this review, we explicate the oncogenic role of these kinases and review recent therapeutic advances in the dawning era of IRAK-targeted therapy.

RECENT FINDINGS

Emerging evidence places IRAK signaling at the confluence of adaptive resistance and oncogenesis in the hematologic malignancies and solid tissue tumors. Preclinical investigations nominate the IRAK kinases as targetable molecular dependencies in diverse cancers.

SUMMARY

IRAK-targeted therapies that have matriculated to early phase trials are yielding promising preliminary results. However, studies of IRAK kinase signaling continue to defy conventional signaling models and raise questions as to the design of optimal treatment strategies. Efforts to refine IRAK signaling mechanisms in the malignant context will inspire deliberate IRAK-targeted drug development and informed combination therapy.