Reciprocal interaction between carcinoma-associated fibroblasts and squamous carcinoma cells through interleukin-1α induces cancer progression

Single-cell multi-stage spatial evolutional map of esophageal carcinogenesis

Cancer development involves the co-evolution of cancer cells and their surrounding microenvironment, yet the dynamics of this interaction within the physical architecture remains poorly understood. Here, we present a spatial transcriptomic map at single-cell resolution, encompassing 127 multi-stage fields of view from 43 patients, to chart the evolutionary trajectories of human esophageal squamous cell carcinoma (ESCC). By analyzing 6.4 million cells, we reveal that ESCC progression is driven by a proliferative epithelial cell subpopulation that acquires dedifferentiated and invasive characteristics. At the late precancerous stage, these cells disrupt the epithelial-stromal interface and recruit normal fibroblasts via JAG1-NOTCH1 signaling, transforming them into cancer-associated fibroblasts (CAFs). This interaction leads to the formation of a "CAF-Epi" (CAF and epithelial cell) niche at the tumor edge that shields the tumor from immune surveillance. The CAF-Epi niche formation is a key indicator of progression in ESCC and other squamous cell carcinomas and patient outcomes.

Biological implications of decoding the extracellular matrix of vulva cancer

The present review aimed to elucidate the roles of extracellular matrix (ECM) components in the progression of vulvar squamous cell carcinoma (VSCC) and explore potential therapeutic avenues for this type of malignancy. This exploration holds promise for identifying precise molecular targets within the ECM milieu, thus facilitating the development of innovative therapeutic modalities tailored to disrupt these interactions and ultimately improve patient outcomes in VSCC. The dysregulated ECM serves as a potent driver of SCC tumor progression, orchestrating key processes such as angiogenesis, inflammation and stromal cell behavior. Yet, the exploration of ECM role in VSCC is still in its early stages. Recent research highlights the critical role of ECM organization and expression within the tumor microenvironment (TME) in influencing key aspects of VSCC, including tumor staging, grading, metastasis, invasion and patient survival. Cancer‑associated fibroblasts play a pivotal role in this dynamic by engaging in reciprocal interactions with VSCC cells, leading to significant ECM alterations and creating an immune‑suppressive TME. This hinders antitumor immunity and fosters therapeutic resistance in VSCC treatment. The dysregulated ECM in VSCC drives tumor progression, metastasis and affects patient survival. Targeting ECM, along with emerging therapies such as immune checkpoint blockade, offers promise for improved VSCC treatment outcomes.

IL-33 aggravates extranodal NK/T cell lymphoma aggressiveness and angiogenesis by activating the Wnt/β-catenin signaling pathway

Extranodal NK/T cell lymphoma (ENKTCL) is an extremely aggressive form of lymphoma and lacks of specific diagnostic markers. The study intended to unearth the role of interleukin-33 (IL-33) in ENKTCL. RT-qPCR was conducted to assess mRNA levels of ENKTCL tissues and cells, while western blot assay was performed for evaluating protein levels. Plate cloning experiment and transwell assay were employed to measure aggressiveness of ENKTCL. Tube formation assay was executed to determine the angiogenesis ability. Mice ENKTCL xenograft model was designed to probe the impacts of IL-33 in vivo. IL-33 and suppression of tumorigenicity 2 receptor (ST2, receptor of IL-33) were enhanced in ENKTCL. IL-33 inhibition suppressed viability, migration, and invasion of ENKTCL cells. Moreover, IL-33 knockdown restricted angiogenesis in human umbilical vein endothelial cells (HUVECs). Furthermore, Wnt/β-catenin pathway associated proteins (β-catenin, c-myc, and cyclin D1) were downregulated by loss of IL-33. However, these impacts were overturned by Wnt/β-catenin signaling agonist lithium chloride (LiCl). Additionally, IL-33 silencing exerted anti-tumor effect via Wnt/β-catenin pathway in vivo. Silencing of IL-33 inhibited ENKTCL tumorigenesis and angiogenesis by inactivating Wnt/β-catenin signaling pathway. As such, IL-33 might be a prospective treatment target for ENKTCL.

Cancer-associated fibroblasts, tumor and radiotherapy: interactions in the tumor micro-environment

Cancer-associated fibroblasts (CAFs) represent a group of genotypically non-malignant stromal cells in the tumor micro-environment (TME) of solid tumors that encompasses up to 80% of the tumor volume. Even though the phenotypic diversity and plasticity of CAFs complicates research, it is well-established that CAFs can affect many aspects of tumor progression, including growth, invasion and therapy resistance. Although anti-tumorigenic properties of CAFs have been reported, the majority of research demonstrates a pro-tumorigenic role for CAFs via (in)direct signaling to cancer cells, immunomodulation and extracellular matrix (ECM) remodeling. Following harsh therapeutic approaches such as radio- and/or chemotherapy, CAFs do not die but rather become senescent. Upon conversion towards senescence, many pro-tumorigenic characteristics of CAFs are preserved or even amplified. Senescent CAFs continue to promote tumor cell therapy resistance, modulate the ECM, stimulate epithelial-to-mesenchymal transition (EMT) and induce immunosuppression. Consequently, CAFs play a significant role in tumor cell survival, relapse and potentially malignant transformation of surviving cancer cells following therapy. Modulating CAF functioning in the TME therefore is a critical area of research. Proposed strategies to enhance therapeutic efficacy include reverting senescent CAFs towards a quiescent phenotype or selectively targeting (non-)senescent CAFs. In this review, we discuss CAF functioning in the TME before and during therapy, with a strong focus on radiotherapy. In the future, CAF functioning in the therapeutic TME should be taken into account when designing treatment plans and new therapeutic approaches.

Glutamine and serum starvation alters the ATP production, oxidative stress, and abundance of mitochondrial RNAs in extracellular vesicles produced by cancer cells

Induction of autophagy represents an effective survival strategy for nutrient-deprived or stressed cancer cells. Autophagy contributes to the modulation of communication within the tumor microenvironment. Here, we conducted a study of the metabolic and signaling implications associated with autophagy induced by glutamine (Gln) and serum starvation and PI3K/mTOR inhibitor and autophagy inducer NVP-BEZ235 (BEZ) in the head and neck squamous cell carcinoma (HNSCC) cell line FaDu. We compared the effect of these different types of autophagy induction on ATP production, lipid peroxidation, mitophagy, RNA cargo of extracellular vesicles (EVs), and EVs-associated cytokine secretome of cancer cells. Both BEZ and starvation resulted in a decline in ATP production. Simultaneously, Gln starvation enhanced oxidative damage of cancer cells by lipid peroxidation. In starved cells, there was a discernible fragmentation of the mitochondrial network coupled with an increase in the presence of tumor susceptibility gene 101 (TSG101) on the mitochondrial membrane, indicative of the sorting of mitochondrial cargo into EVs. Consequently, the abundance of mitochondrial RNAs (mtRNAs) in EVs released by FaDu cells was enhanced. Notably, mtRNAs were also detectable in EVs isolated from the serum of both HNSCC patients and healthy controls. Starvation and BEZ reduced the production of EVs by cancer cells, yet the characteristic molecular profile of these EVs remained unchanged. We also found that alterations in the release of inflammatory cytokines constitute a principal response to autophagy induction. Importantly, the specific mechanism driving autophagy induction significantly influenced the composition of the EVs-associated cytokine secretome.

Secretome and immune cell attraction analysis of head and neck cancers

Immune checkpoint inhibitors are approved for recurrent/metastatic head and neck squamous cell carcinoma (HNSCC) but the response rate is only 13-18%. For an effective antitumor immune response, trafficking of immune cells to the tumor microenvironment (TME) is essential. We aimed to better understand immune cell migration as well as the involved chemokines in HNSCC. A transwell assay was used to study immune cell migration toward TME-conditioned medium. While T cell migration was not observed, conventional dendritic cell (cDC) migration was induced by TME-conditioned media. cDC migration correlated with various proteins in the TME secretome. CCL8, CXCL5, CCL13 and CCL7 were tested in validation experiments and addition of these chemokines induced cDC migration. Using single cell RNA-sequencing, we observed expression of CCL8, CXCL5, CCL13 and CCL7 in cancer-associated fibroblasts (CAFs). Depleting fibroblasts led to reduced cDC migration. Thus CAFs, while often seen as suppressors of antitumor immunity, play a role in attracting cDCs toward the head and neck cancer TME, which might be crucial for effective antitumor immunity and response to therapies. Indeed, we found RNA expression signatures of the indicated chemokines, cDC and CAF subpopulations, to be significantly higher in baseline tumor specimen of patients with a major pathological response to pre-surgical anti-PD-1 treatment compared to non-responding patients.

Heterogeneity of cancer-associated fibroblasts and tumor-promoting roles in head and neck squamous cell carcinoma

Tumor microenvironment (TME) in head and neck squamous cell carcinoma (HNSCC) has a major influence on disease progression and therapy response. One of the predominant stromal cell types in the TME of HNSCC is cancer-associated fibroblasts (CAF). CAF constitute a diverse cell population and we are only at the beginning of characterizing and understanding the functions of various CAF subsets. CAF have been shown to interact with tumor cells and other components of the TME to shape mainly a favourable microenvironment for HNSCC progression, although some studies report existence of tumor-restraining CAF subtypes. The numerous pathways used by CAF to promote tumorigenesis may represent potential therapeutic targets. This review summarizes current knowledge on the origins, subtypes and mechanisms employed by CAF in HNSCC. The aim is to contribute to the understanding on how CAF actively influence the TME and modulate different immune cell types, as well as cancer cells, to establish a conducive setting for cancer growth. Although CAF are currently a promising therapeutic target for the treatment of other types of cancer, there is no significant therapeutic advancement in HNSCC.

Immune Escape Strategies in Head and Neck Cancer: Evade, Resist, Inhibit, Recruit

Head and neck cancers (HNCs) arise from the mucosal lining of the aerodigestive tract and are often associated with alcohol use, tobacco use, and/or human papillomavirus (HPV) infection. Over 600,000 new cases of HNC are diagnosed each year, making it the sixth most common cancer worldwide. Historically, treatments have included surgery, radiation, and chemotherapy, and while these treatments are still the backbone of current therapy, several immunotherapies have recently been approved by the Food and Drug Administration (FDA) for use in HNC. The role of the immune system in tumorigenesis and cancer progression has been explored since the early 20th century, eventually coalescing into the current three-phase model of cancer immunoediting. During each of the three phases-elimination, equilibrium, and escape-cancer cells develop and utilize multiple strategies to either reach or remain in the final phase, escape, at which point the tumor is able to grow and metastasize with little to no detrimental interference from the immune system. In this review, we summarize the many strategies used by HNC to escape the immune system, which include ways to evade immune detection, resist immune cell attacks, inhibit immune cell functions, and recruit pro-tumor immune cells.

The Three-Dimensional In Vitro Cell Culture Models in the Study of Oral Cancer Immune Microenvironment

The onset and progression of oral cancer are accompanied by a dynamic interaction with the host immune system, and the immune cells within the tumor microenvironment play a pivotal role in the development of the tumor. By exploring the cellular immunity of oral cancer, we can gain insight into the contribution of both tumor cells and immune cells to tumorigenesis. This understanding is crucial for developing effective immunotherapeutic strategies to combat oral cancer. Studies of cancer immunology present unique challenges in terms of modeling due to the extraordinary complexity of the immune system. With its multitude of cellular components, each with distinct subtypes and various activation states, the immune system interacts with cancer cells and other components of the tumor, ultimately shaping the course of the disease. Conventional two-dimensional (2D) culture methods fall short of capturing these intricate cellular interactions. Mouse models enable us to learn about tumor biology in complicated and dynamic physiological systems but have limitations as the murine immune system differs significantly from that of humans. In light of these challenges, three-dimensional (3D) culture systems offer an alternative approach to studying cancer immunology and filling the existing gaps in available models. These 3D culture models provide a means to investigate complex cellular interactions that are difficult to replicate in 2D cultures. The direct study of the interaction between immune cells and cancer cells of human origin offers a more relevant and representative platform compared to mouse models, enabling advancements in our understanding of cancer immunology. This review explores commonly used 3D culture models and highlights their significant contributions to expanding our knowledge of cancer immunology. By harnessing the power of 3D culture systems, we can unlock new insights that pave the way for improved strategies in the battle against oral cancer.

The Clinical Significance and Role of CXCL1 Chemokine in Gastrointestinal Cancers

One area of cancer research is the interaction between cancer cells and immune cells, in which chemokines play a vital role. Despite this, a comprehensive summary of the involvement of C-X-C motif ligand 1 (CXCL1) chemokine (also known as growth-regulated gene-α (GRO-α), melanoma growth-stimulatory activity (MGSA)) in cancer processes is lacking. To address this gap, this review provides a detailed analysis of CXCL1's role in gastrointestinal cancers, including head and neck cancer, esophageal cancer, gastric cancer, liver cancer (hepatocellular carcinoma (HCC)), cholangiocarcinoma, pancreatic cancer (pancreatic ductal adenocarcinoma), and colorectal cancer (colon cancer and rectal cancer). This paper presents the impact of CXCL1 on various molecular cancer processes, such as cancer cell proliferation, migration, and invasion, lymph node metastasis, angiogenesis, recruitment to the tumor microenvironment, and its effect on immune system cells, such as tumor-associated neutrophils (TAN), regulatory T (T_reg) cells, myeloid-derived suppressor cells (MDSCs), and macrophages. Furthermore, this review discusses the association of CXCL1 with clinical aspects of gastrointestinal cancers, including its correlation with tumor size, cancer grade, tumor-node-metastasis (TNM) stage, and patient prognosis. This paper concludes by exploring CXCL1's potential as a therapeutic target in anticancer therapy.

Blockade of IL-1α and IL-1β signaling by the anti-IL1RAP antibody nadunolimab (CAN04) mediates synergistic anti-tumor efficacy with chemotherapy

IL-1α and IL-1β are both involved in several aspects of tumor biology, including tumor initiation, progression, metastasis, and not least in resistance to various therapies. IL-1α can function as an alarmin to signal cellular stress, and acts to induce downstream events, including production of IL-1β, to amplify the signal. Both IL-1α and IL-1β act through the same receptor complex, IL-1R1-IL1RAP, to mediate signal transduction. IL1RAP is expressed on tumor cells and in the tumor microenvironment by for example CAF, macrophages and endothelial cells. The anti-IL1RAP antibody nadunolimab (CAN04) inhibits both IL-1α and IL-1β signaling and induces ADCC of IL1RAP-expressing tumor cells. As both IL-1α and IL-1β mediate chemoresistance, the aim of this study was to explore the potential synergy between nadunolimab and chemotherapy. This was performed using the NSCLC PDX model LU2503 and the syngeneic MC38 model, in addition to in vitro cell line experiments. We show that chemotherapy induces expression and release of IL-1α from tumor cells and production of IL-1β-converting enzyme, ICE, in the tumor stroma. IL-1α is also demonstrated to act on stromal cells to further induce the secretion of IL-1β, an effect disrupted by nadunolimab. Nadunolimab, and its surrogate antibody, synergize with platinum-based as well as non-platinum-based chemotherapy to induce potent anti-tumor effects, while blockade of only IL-1β signaling by anti-IL-1β antibody does not achieve this effect. In conclusion, blockade of IL1RAP with nadunolimab reduces IL-1-induced chemoresistance of tumors.

Oral Squamous Cell Carcinoma-Derived ANGPTL3 Induces Cancer Associated Fibroblastic Phenotypes in Surrounding Fibroblasts

OBJECTIVE

Angiopoietin-like proteins (ANGPTLs) have emerged as both important regulator of lipid and glucose metabolism as well as insulin sensitivity. In particular, ANGPTL3 activity is one of the most important factors in cancer growth and invasion. Although ANGPTL3 have been studied in OSCC, but the role of ANGPTL3 between OSCC and CAFs has yet to be clearly defined. Thus, this study aimed to investigate the roles of ANGPTL3 in the differentiation of CAFs.

METHODS

For our study, we used hTERT-hNOFs to replace CAFs by coculturing them with oral squamous cell carcinoma (OSCC) cells. We did a microarray dataset analysis to investigate what factors secreted from OSCC cells can induce cancer associated fibroblastic phenotype in surrounding fibroblasts. The secreted factors were confirmed by RT-PCR, real-time PCR, and Western blot.

RESULT

ANGPTL3 has the most secreted factor derived from various oral cancer cells. To investigate the role of ANGPTL3 in CAFs, we treated rhANGPTL3 in hTERT-hNOFs. The fibroblasts showed an increase of tumor-promoting cytokines (IL-6 and IL-8) and myofibroblastic markers, such as α-SMA and FAP.

CONCLUSION

In conclusion, our study reports the first evidence that ANGPTL3 plays a crucial role in tumor microenvironments by inducing CAF. Therefore, targeting ANGPTL3 may be promising treatment strategy for CAF-targeted therapy in CAF-rich tumors.

The Role of Cytokinome in the HNSCC Tumor Microenvironment: A Narrative Review and Our Experience

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer. In locally advanced (LA) HNSCC, a multidisciplinary approach consisting of surgery followed by chemoradiation (CRT) or definitive CRT is the mainstay of treatment. In recurrent metastatic (R/M), HNSCC immune checkpoint inhibitors (ICIs) with or without chemotherapy represent the new first-line option. However, cancer will recur in about two out of five patients with LA HNSCC. If progression occurs within six months from platin-radiotherapy treatment, anti-programmed cell death-1 (PD-1) may be prescribed. Otherwise, immunotherapy with or without chemotherapy might be considered if PD-L1 is expressed. Despite several improvements in the outcome of patients with R/M HNSCC, overall survival (OS) remains dismal, equaling a median of 14 months. In-depth knowledge of the tumor microenvironment (TME) would be required to change the course of this complex disease. In recent years, many predictive and prognostic biomarkers have been studied in the HNSCC TME, but none of them alone can select the best candidates for response to ICIs or targeted therapy (e.g., Cetuximab). The presence of cytokines indicates an immune response that might occur, among other things, after tumor antigen recognition, viral and bacterial infection, and physic damage. An immune response against HNSCC results in the production of some cytokines that induce a pro-inflammatory response and attract cells, such as neutrophils, macrophages, and T cell effectors, to enhance the innate and adaptive anti-tumor response. We revised the role of a group of cytokines as biomarkers for treatment response in HNSCC.

The Multiple Roles of CD147 in the Development and Progression of Oral Squamous Cell Carcinoma: An Overview

Cluster of differentiation (CD)147, also termed extracellular matrix metalloprotease inducer or basigin, is a glycoprotein ubiquitously expressed throughout the human body, the oral cavity included. CD147 actively participates in physiological tissue development or growth and has important roles in reactive processes such as inflammation, immunity, and tissue repair. It is worth noting that deregulated expression and/or activity of CD147 is observed in chronic inflammatory or degenerative diseases, as well as in neoplasms. Among the latter, oral squamous cell carcinoma (OSCC) is characterized by an upregulation of CD147 in both the neoplastic and normal cells constituting the tumor mass. Most interestingly, the expression and/or activity of CD147 gradually increase as healthy oral mucosa becomes inflamed; hyperplastic/dysplastic lesions are then set on, and, eventually, OSCC develops. Based on these findings, here we summarize published studies which evaluate whether CD147 could be employed as a marker to monitor OSCC development and progression. Moreover, we describe CD147-promoted cellular and molecular events which are relevant to oral carcinogenesis, with the aim to provide useful information for assessing whether CD147 may be the target of novel therapeutic approaches directed against OSCC.

Vasopressin Receptor Type-2 Mediated Signaling in Renal Cell Carcinoma Stimulates Stromal Fibroblast Activation

Vasopressin type-2 receptor (V2R) is ectopically expressed and plays a pathogenic role in clear cell renal cell carcinoma (ccRCC) tumor cells. Here we examined how V2R signaling within human ccRCC tumor cells (Caki1 cells) stimulates stromal cancer-associated fibroblasts (CAFs). We found that cell culture conditioned media from Caki1 cells increased activation, migration, and proliferation of fibroblasts in vitro, which was inhibited by V2R gene silencing in Caki1 cells. Analysis of the conditioned media and mRNA of the V2R gene silenced and control Caki1 cells showed that V2R regulates the production of CAF-activating factors. Some of these factors were also found to be regulated by YAP in these Caki1 cells. YAP expression colocalized and correlated with V2R expression in ccRCC tumor tissue. V2R gene silencing or V2R antagonist significantly reduced YAP in Caki1 cells. Moreover, the V2R antagonist reduced YAP expression and myofibroblasts in mouse xenograft tumors. These results suggest that V2R plays an important role in secreting pro-fibrotic factors that stimulate fibroblast activation by a YAP-dependent mechanism in ccRCC tumors. Our results demonstrate a novel role for the V2R-YAP axis in the regulation of myofibroblasts in ccRCC and a potential therapeutic target.

The Role of Immune Modulatory Cytokines in the Tumor Microenvironments of Head and Neck Squamous Cell Carcinomas

Simple Summary

Malignant phenotypes of head and neck squamous cell carcinomas (HNSCCs) are regulated by the pro- and anti-tumoral activities of immune modulatory cytokines associated with tumor microenvironments (TMEs). We first present the immune modulatory effects of pro-inflammatory cytokines, pro- and anti- (pro-/anti-) inflammatory cytokines, and anti-inflammatory cytokines upon HNSCC phenotypes. We then report our evaluation of the functions of cytokines and chemokines that mediate the crosstalk between tumors and stromal cells, including cancer-associated fibroblasts (CAFs), myeloid-derived suppressor cells (MDSCs), plasmacytoid dendritic cells (pDCs), and tumor-associated macrophages (TAMs). In HNSCCs, the status of lymph node metastasis is an important hallmark of a worse prognosis. Several chemokines mediate lymph node metastases in HNSCC patients. There are therapeutic approaches, using antitumoral cytokines or immunotherapies, that target cytokines, chemokines, or signal molecules essential for the immune evasion of HNSCCs. Finally, modulation by human papilloma virus (HPV) infection in HNSCC phenotypes and the prognostic significance of serum cytokine levels in HNSCC patients are discussed.

Abstract

HNSCCs are the major progressive malignancy of the upper digestive and respiratory organs. Malignant phenotypes of HNSCCs are regulated by the pro- and anti-tumoral activities of the immune modulatory cytokines associated with TMEs, i.e., a representative pro-inflammatory cytokine, interferon (IFN)-γ, plays a role as an anti-tumor regulator against HNSCCs; however, IFN-γ also drives programmed death-ligand (PD-L) 1 expression to promote cancer stem cells. Interleukin (IL)-2 promotes the cytotoxic activity of T cells and natural killer cells; however, endogenous IL-2 can promote regulatory T cells (Tregs), resulting in the protection of HNSCCs. In this report, we first classified and mentioned the immune modulatory aspects of pro-inflammatory cytokines, pro-/anti-inflammatory cytokines, and anti-inflammatory cytokines upon HNSCC phenotypes. In the TME of HNSCCs, pro-tumoral immune modulation is mediated by stromal cells, including CAFs, MDSCs, pDCs, and TAMs. Therefore, we evaluated the functions of cytokines and chemokines that mediate the crosstalk between tumor cells and stromal cells. In HNSCCs, the status of lymph node metastasis is an important hallmark of a worse prognosis. We therefore evaluated the possibility of chemokines mediating lymph node metastases in HNSCC patients. We also mention therapeutic approaches using anti-tumoral cytokines or immunotherapies that target cytokines, chemokines, or signal molecules essential for the immune evasion of HNSCCs. We finally discuss modulation by HPV infection upon HNSCC phenotypes, as well as the prognostic significance of serum cytokine levels in HNSCC patients.

Inflammatory Mediators in Oral Cancer: Pathogenic Mechanisms and Diagnostic Potential

Approximately 15% of cancers are attributable to the inflammatory process, and growing evidence supports an association between oral squamous cell carcinoma (OSCC) and chronic inflammation. Different oral inflammatory conditions, such as oral lichen planus (OLP), submucous fibrosis, and oral discoid lupus, are all predisposing for the development of OSCC. The microenvironment of these conditions contains various transcription factors and inflammatory mediators with the ability to induce proliferation, epithelial-to-mesenchymal transition (EMT), and invasion of genetically predisposed lesions, thereby promoting tumor development. In this review, we will focus on the main inflammatory molecules and transcription factors activated in OSCC, with emphasis on their translational potential.

Mitogen-activated protein kinase-activated protein kinase-2 (MK2) and its role in cell survival, inflammatory signaling, and migration in promoting cancer

Cancer and the immune system share an intimate relationship. Chronic inflammation increases the risk of cancer occurrence and can also drive inflammatory mediators into the tumor microenvironment enhancing tumor growth and survival. The p38 MAPK pathway is activated both acutely and chronically by stress, inflammatory chemokines, chronic inflammatory conditions, and cancer. These properties have led to extensive efforts to find effective drugs targeting p38, which have been unsuccessful. The immediate downstream serine/threonine kinase and substrate of p38 MAPK, mitogen-activated-protein-kinase-activated-protein-kinase-2 (MK2) protects cells against stressors by regulating the DNA damage response, transcription, protein and messenger RNA stability, and motility. The phosphorylation of downstream substrates by MK2 increases inflammatory cytokine production, drives an immune response, and contributes to wound healing. By binding directly to p38 MAPK, MK2 is responsible for the export of p38 MAPK from the nucleus which gives MK2 properties that make it unique among the large number of p38 MAPK substrates. Many of the substrates of both p38 MAPK and MK2 are separated between the cytosol and nucleus and interfering with MK2 and altering this intracellular translocation has implications for the actions of both p38 MAPK and MK2. The inhibition of MK2 has shown promise in combination with both chemotherapy and radiotherapy as a method for controlling cancer growth and metastasis in a variety of cancers. Whereas the current data are encouraging the field requires the development of selective and well tolerated drugs to target MK2 and a better understanding of its effects for effective clinical use.

IL-1/IL-1R Signaling in Head and Neck Cancer

Decades ago, the study of cancer biology was mainly focused on the tumor itself, paying little attention to the tumor microenvironment (TME). Currently, it is well recognized that the TME plays a vital role in cancer development and progression, with emerging treatment strategies focusing on different components of the TME, including tumoral cells, blood vessels, fibroblasts, senescent cells, inflammatory cells, inflammatory factors, among others. There is a well-accepted relationship between chronic inflammation and cancer development. Interleukin-1 (IL-1), a potent pro-inflammatory cytokine commonly found at tumor sites, is considered one of the most important inflammatory factors in cancer, and has been related with carcinogenesis, tumor growth and metastasis. Increasing evidence has linked development of head and neck squamous cell carcinoma (HNSCC) with chronic inflammation, and particularly, with IL-1 signaling. This review focuses on the most important members of the IL-1 family, with emphasis on how their aberrant expression can promote HNSCC development and metastasis, highlighting possible clinical applications.

Cancer-Associated Fibroblasts in Oral Cancer: A Current Perspective on Function and Potential for Therapeutic Targeting

The role of the tumour microenvironement (TME) in cancer progression and resistance to therapies is now widely recognized. The most prominent non-immune cell type in the microenvironment of oral cancer (OSCC) is cancer-associated fibroblasts (CAF). Although CAF are a poorly characterised and heterogenous cell population, those with an "activated" myofibroblastic phenotype have been shown to support OSCC progression, promoting growth, invasion and numerous other "hallmarks of malignancy." CAF also confer broad resistance to different types of therapy, including chemo/radiotherapy and EGFR inhibitors; consistent with this, CAF-rich OSCC are associated with poor prognosis. In recent years, much CAF research has focused on their immunological role in the tumour microenvironment, showing that CAF shield tumours from immune attack through multiple mechanisms, and particularly on their role in promoting resistance to anti-PD-1/PD-L1 checkpoint inhibitors, an exciting development for the treatment of recurrent/metastatic oral cancer, but which fails in most patients. This review summarises our current understanding of CAF subtypes and function in OSCC and discusses the potential for targeting these cells therapeutically.

CC Chemokine Ligand 7 Derived from Cancer-Stimulated Macrophages Promotes Ovarian Cancer Cell Invasion

In the tumor microenvironment, macrophages have been suggested to be stimulated by tumor cells, becoming tumor-associated macrophages that promote cancer development and progression. We examined the effect of these macrophages on human ovarian cancer cell invasion and found that conditioned medium of macrophages stimulated by ovarian cancer cells (OC-MQs) significantly increased cell invasion. CC chemokine ligand 7 (CCL7) expression and production were significantly higher in OC-MQs than in the control macrophages. Peritoneal macrophages from patients with ovarian cancer showed higher CCL7 expression levels than those from healthy controls. Inhibition of CCL7 using siRNA and neutralizing antibodies reduced the OC-MQ-CM-induced ovarian cancer cell invasion. CC chemokine receptor 3 (CCR3) was highly expressed in human ovarian cancer cells, and a specific inhibitor of this receptor reduced the OC-MQ-CM-induced invasion. Specific signaling and transcription factors were associated with enhanced CCL7 expression in OC-MQs. CCL7-induced invasion required the expression of matrix metalloproteinase 9 via activation of extracellular signal-related kinase signaling in human ovarian cancer cells. These data suggest that tumor-associated macrophages can affect human ovarian cancer metastasis via the CCL7/CCR3 axis.

Targeting fibroblast activation protein in newly diagnosed squamous cell carcinoma of the oral cavity - initial experience and comparison to [18F]FDG PET/CT and MRI

Purpose

While [¹⁸F]-fluorodeoxyglucose ([¹⁸F]FDG) is the standard for positron emission tomography/computed tomography (PET/CT) imaging of oral squamous cell carcinoma (OSCC), diagnostic specificity is hampered by uptake in inflammatory cells such as neutrophils or macrophages. Recently, molecular imaging probes targeting fibroblast activation protein α (FAP), which is overexpressed in a variety of cancer-associated fibroblasts, have become available and might constitute a feasible alternative to FDG PET/CT.

Methods

Ten consecutive, treatment-naïve patients (8 males, 2 females; mean age, 62 ± 9 years) with biopsy-proven OSCC underwent both whole-body [¹⁸F]FDG and [⁶⁸Ga]FAPI-04 (FAP-directed) PET/CT for primary staging prior to tumor resection and cervical lymph node dissection. Detection of the primary tumor, as well as the presence and number of lymph node and distant metastases was analysed. Intensity of tracer accumulation was assessed by means of maximum (SUV_max) and peak (SUV_peak) standardized uptake values. Histological work-up including immunohistochemical staining for FAP served as standard of reference.

Results

[¹⁸F]FDG and FAP-directed PET/CT detected all primary tumors with a SUV_max of 25.5 ± 13.2 (FDG) and 20.5 ± 6.4 (FAP-directed) and a SUV_peak of 16.1 ± 10.3 ([¹⁸F]FDG) and 13.8 ± 3.9 (FAP-directed), respectively. Regarding cervical lymph node metastases, FAP-directed PET/CT demonstrated comparable sensitivity (81.3% vs. 87.5%; P = 0.32) and specificity (93.3% vs. 81.3%; P = 0.16) to [¹⁸F]FDG PET/CT. FAP expression on the cell surface of cancer-associated fibroblasts in both primary lesions as well as lymph nodes metastases was confirmed in all samples.

Conclusion

FAP-directed PET/CT in OSCC seems feasible. Future research to investigate its potential to improve patient staging is highly warranted.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00259-021-05422-z.

In situ immunopathological events in human cervical intraepithelial neoplasia and cervical cancer: Review

Neoplasia of the cervix represents one of the most common cancers in women. Clinical and molecular research has identified immunological impairment in squamous intraepithelial cervical lesions and cervical cancer patients. The in-situ expression of several cytokines by uterine epithelial cells and by infiltrating leukocytes occurs during the cervical intraepithelial neoplasia and cervical cancer. Some of these cytokines can prevent and others can induce the progression of the neoplasm. The infiltrating leukocytes also produce cytokines and growth factors relate to angiogenesis, chemotaxis, and apoptosis capable of modulating the dysplasia progression. In this review we analyzed several interleukins with an inductive effect or blocking effect on the neoplastic progression. We also analyze the genetic polymorphism of some cytokines and their relationship with the risk of developing cervical neoplasia. In addition, we describe the leukocyte cells that infiltrate the cervical uterine tissue during the neoplasia and their effects on neoplasia progression.

Cancer-associated fibroblasts promote tumor progression by lncRNA-mediated RUNX2/GDF10 signaling in oral squamous cell carcinoma

Cancer-associated fibroblasts (CAF) are the most abundant stromal cells in tumor and exert a pro-tumoral effect in cancer progression. Numerous evidence shows long non-coding RNA (lncRNA) abnormally regulates gene expression in various cancers. However, little is known about the role of lncRNA in the interaction between CAF and cancer cells. Here, we first identify an uncharacterized lncRNA, LOC100506114, which is significantly upregulated in CAF and is involved in the functional transformation of normal fibroblasts (NF) and CAF. Expression of LOC100506114 enhances the expression of fibroblast activation protein alpha and α-smooth muscle actin in NF and promotes malignant characteristics of NF and CAF in vivo and in vitro. The profile of gene co-expression analysis shows that growth differentiation factor 10 (GDF10) is positively correlated with the expression of LOC100506114. CAF promote stromal fibroblast activation and the proliferation and migration of tumor cells by secreting GDF10. Our data demonstrate that lncRNA plays a critical role in the interplay of stromal fibroblasts and tumor cells in oral squamous cell carcinoma.

P2 purinergic receptor signaling and interleukin-1 synergistically induce interleukin-6 production in a human oral squamous carcinoma cell line

OBJECTIVES

The aim of this study was to investigate the inflammatory roles of P2 purinergic receptor (P2R) signaling in oral squamous cell carcinoma (OSCC).

METHODS

Human OSCC cell lines HSC-2, Ca9-22, and HO-1-u-1 were stimulated with P2R agonists. The concentration of interleukin (IL)-6 in culture supernatants was measured using an enzyme-linked immune sorbent assay. Expression levels of messenger RNAs (mRNAs) were analyzed using reverse transcription polymerase chain reaction. Phosphorylation of intracellular signaling molecules was analyzed using western blotting.

RESULTS

HSC-2 cells expressed the mRNAs for P2X4-6 and all P2YRs. ATP or ADP induced significantly greater production of IL-6 by HSC-2 cells. Ca9-22 cells expressed mRNAs for P2X4-6 and all P2YRs except P2Y4. ATP or ADP induced the production of IL-6 by Ca9-22 cells, but the IL-6 concentration was much lower than that in HSC-2 cells. Although HO-1-u-1 cells expressed the mRNAs for P2X4-6 and all P2YRs, ATP or ADP did not induce IL-6 production. The production of IL-6 by HSC-2 cells stimulated with adenine nucleotides was significantly inhibited by P2R antagonists and a p38 mitogen-activated protein kinase inhibitor, but not by extracellular signal-related kinase or c-Jun N-terminal kinase inhibitors. The proinflammatory cytokine IL-1 significantly augmented P2R-induced IL-6 production by HSC-2 cells via the nuclear factor-κB signaling pathway.

CONCLUSIONS

The present study suggests that P2Rs signaling and IL-1 synergistically induce chronic inflammation in OSCC. Because chronic inflammation is a well-known driving force of tumor progression, these results support therapeutic strategies that target P2Rs signaling in OSCC.

IL-1α Processing, Signaling and Its Role in Cancer Progression

Interleukin-1α (IL-1α) is a major alarmin cytokine which triggers and boosts the inflammatory responses. Since its discovery in the 1940s, the structure and bioactivity of IL-1α has been extensively studied and emerged as a vital regulator in inflammation and hematopoiesis. IL-1α is translated as a pro-form with minor bioactivity. The pro-IL-1α can be cleaved by several proteases to generate the N terminal and C terminal form of IL-1α. The C terminal form of IL-1α (mature form) has several folds higher bioactivity compared with its pro-form. IL-1α is a unique cytokine which could localize in the cytosol, membrane, nucleus, as well as being secreted out of the cell. However, the processing mechanism and physiological significance of these differentially localized IL-1α are still largely unknown. Accumulating evidence suggests IL-1α is involved in cancer pathogenesis. The role of IL-1α in cancer development is controversial as it exerts both pro- and anti-tumor roles in different cancer types. Here, we review the recent development in the processing and signaling of IL-1α and summarize the functions of IL-1α in cancer development.

CXCL3 Signaling in the Tumor Microenvironment

Cancer progression is driven, to a large extent, by the action of immune cells that have been recruited to tumor sites through interactions between chemokines and their receptors. Chemokines of the CXC subfamily are secreted by both tumor and non-tumor cells within the microenvironment of the tumor, where they induce either antitumor or protumor activity that fosters either clearance or progression of the tumor, respectively. Understanding the nature of these interactions is important to envisage novel approaches targeting the essential components of the tumor microenvironment, increasing the odds for favorable patient outcomes. In this chapter we describe the involvement of the chemokine (C-X-C motif) ligand 3 (CXCL3) in the human tumor microenvironment and its effects on immune and non-immune cells. Because of the limited data on the CXCL3 signaling in the tumor microenvironment, we extend the review to other members of the CXC subfamily of chemokines. This review also addresses the future trends or directions for therapeutic interventions that target signaling pathways used by these molecules in the tumor microenvironment.

Improved cancer detection in Waldeyer's tonsillar ring by 68Ga-FAPI PET/CT imaging

Purpose

In cancer of unknown primary (CUP), positron emission tomography/computed tomography (PET/CT) with the glucose analog [¹⁸F]FDG represents the standard imaging approach for localization of the malignant primary. Frequently, however, [¹⁸F]FDG PET/CT cannot precisely distinguish between small occult tumors and chronic inflammation, especially in Waldeyer’s tonsillar ring. To improve the accuracy for detecting primary tumors in the Waldeyer’s tonsillar ring, the novel PET tracer [⁶⁸Ga]Ga-FAPI-4 for specific imaging of fibroblast activation protein (FAP) expression was used as a more specific target for cancer imaging.

Methods

Eight patients with suspicion of a malignant tumor in Waldeyer’s tonsillar ring or a CUP syndrome were examined. PET/CT scans with [¹⁸F]-FDG and [⁶⁸Ga]Ga-FAPI-4 were performed for pre-operative tumor localization. After surgical resection, histopathological and immunohistochemical results were compared to PET/CT findings.

Results

Histopathology revealed a palatine or lingual tonsil carcinoma in all patients. In case of lymph node metastases smaller than 7 mm in size, the [¹⁸F]FDG PET/CT detection rate of cervical lymph node metastases was higher than that of [⁶⁸Ga]FAPI PET/CT, while both tracers identified the primary tumors in all eight cases. The size of the primary and the lymph node metastases was directly correlated to the respective FAP expression, as detected by immunohistochemistry. The mean SUV_max for the primary tumors was 21.29 ± 7.97 for ¹⁸F-FDG and 16.06 ± 6.29 for ⁶⁸Ga-FAPI, respectively (p = 0.2). The mean SUV_max for the healthy contralateral tonsils was 8.38 ± 2.45 for [¹⁸F]FDG and 3.55 ± 0.47 for [⁶⁸Ga]FAPI (p < 0.001). The SUV_max ratio of [⁶⁸Ga]FAPI was significantly different from [¹⁸F] FDG (p = 0.03). Mean TBR_max for the [⁶⁸Ga]Ga-FAPI-4 tracer was markedly higher in comparison to [¹⁸F]FDG (10.90 vs. 4.11).

Conclusion

Non-invasive imaging of FAP expression by [⁶⁸Ga]FAPI PET/CT resulted in a better visual detection of the malignant primary in CUP, as compared to [¹⁸F]FDG imaging. However, the detection rate of lymph node metastases was inferior, presumably due to low FAP expression in small metastases. Nevertheless, by offering a detection method for primary tumors with the potential of lower false positive rates and thus avoiding biopsies, patients with CUP syndrome may benefit from [⁶⁸Ga]FAPI PET/CT imaging.

The Axin2-snail axis promotes bone invasion by activating cancer-associated fibroblasts in oral squamous cell carcinoma

Background

In bone-invasive oral squamous cell carcinoma (OSCC), cancer-associated fibroblasts (CAFs) infiltrate into bony tissue ahead of OSCC cells. In the present study, we aimed to investigate the role of the Axin2-Snail axis in the biological behaviour of CAFs and bone invasion in OSCC.

Methods

The clinicopathological significance of Axin2 and Snail expression was investigated by immunohistochemistry in an OSCC cohort containing 217 tissue samples from patients with long-term follow-up. The influence of the Axin2-Snail axis on the biological behaviour of OSCC cells and CAFs was further investigated both in vitro and in vivo.

Results

Axin2 expression was significantly associated with Snail expression, the desmoplasia status, and bone invasion in patients with OSCC. In multivariate analysis, lymph node metastasis, desmoplasia, Axin2 expression, and Snail expression were independent poor prognostic factors in our cohort. Consistent with these findings, OSCC cells demonstrated attenuated oncogenic activity as well as decreased expression of Snail and various cytokines after Axin2 knockdown in vitro. Among the related cytokines, C-C motif chemokine ligand 5 (CCL5) and interleukin 8 (IL8) demonstrated a strong influence on the biological behaviour of CAFs in vitro. Moreover, both the desmoplastic reaction and osteolytic lesions in the calvaria were predominantly decreased after Axin2 knockdown in OSCC cells in vivo using a BALB/c athymic nude mouse xenograft model.

Conclusions

Oncogenic activities of the Axin2-Snail axis are not limited to the cancer cells themselves but rather extend to CAFs via regulation of the cytokine-mediated cancer-stromal interaction, with further implications for bone invasion as well as a poor prognosis in OSCC.

The Protective Effect of Antioxidants in Areca Nut Extract-Induced Oral Carcinogenesis

Objective:

Oral submucous fibrosis (OSF) is the premalignant disorder associated with fibrosis and epithelial atrophy. Areca Nut (AN) is the most significant risk factors for OSF. However, the molecular mechanism behind AN induced OSF remains unclear, and there exists no effective treatment for the malignant disorder. We aimed to investigate whether AN-extract causes epithelial-mesenchymal transition (EMT) in oral keratinocytes, and evaluated the therapeutic potential of antioxidants.

Methods:

The HPV16 E6/E7-transfected immortalized human oral keratinocytes (IHOK) were employed in the present study. For the preparation of AN-extract, dried AN was dissolved in distilled water overnight. The solution was centrifuged and the supernatant was collected for further use. For the determination of change in cytokine levels, ELISA was performed. To investigate EMT-related protein expression and phenotype, immunoblot and immunofluorescence were performed.

Results:

Among tumor-promoting cytokines (Gro-α, IL-6 and IL-8), IL-6 was remarkably increased by AN in IHOK. AN-extract induced EMT phenotypes, such as cell elongation, up-regulation of vimentin and snail. After treatment with neutralizing antibody of IL-6, AN-induced snail expression was reduced remarkably. Collectively, AN-extract induced IL-6 expression and mediated EMT. The use of antioxidants (EGCG, glutathione and NAC) significantly reduced IL-6 expression in AN-treated IHOK. Also, AN-decreased E-cadherin and increased vimentin were reversed by antioxidants, indicating that the effectiveness of antioxidants in inhibiting IL-6-induced EMT by AN.

Conclusion:

AN promotes EMT and antioxidants interrupt AN-induced-EMT in oral keratinocytes. Consequently, it is proposed that antioxidants could prevent AN-induced carcinogenesis and function as a prototype for developing therapeutic interventions of OSF.

Gene expression profiling of tumor stroma interactions in retinoblastoma

We aimed to identify the critical molecular pathways altered upon tumor stroma interactions in retinoblastoma (RB). In vitro 2 D cocultures of RB tumor cells (Weri-Rb-1 and NCC-RbC-51) with primary bone marrow stromal cells (BMSC) was established. Global gene expression patterns in coculture samples were assessed using Affymetrix Prime view human gene chip microarray and followed with bioinformatics analyses. Key upregulated genes from Weri-Rb-1 + BMSC and NCC-RbC-51 + BMSC coculture were validated using qRT-PCR to ascertain their role in RB progression. Whole genome microarray experiments identified significant (P ≤ 0.05, 1.1 log 2 FC) transcriptome level changes induced upon coculture of RB cells with BMSC. A total of 1155 genes were downregulated and 1083 upregulated in Weri-Rb-1 + BMSC coculture. Similarly, 1865 genes showed downregulation and 1644 genes were upregulation in NCC-RbC-51 + BMSC coculture. The upregulated genes were significantly associated with pathways of focal adhesion, PI3K-Akt signalling, ECM-receptor interaction, JAK-STAT, TGF-β signalling thus contributing to RB progression. Validation of key genes by qRT-PCR revealed significant overexpression of IL8, IL6, MYC and SMAD3 in the case of Weri-Rb-1 + BMSC coculture and IL6 in the case of NCC-RbC-51 + BMSC coculture. The microarray expression study on in vitro RB coculture models revealed the pathways that could be involved in the progression of RB. The gene signature obtained in a stimulated model when a growing tumor interacts with its microenvironment may provide new horizons for potential targeted therapy in RB.

A TRACER culture invasion assay to probe the impact of cancer associated fibroblasts on head and neck squamous cell carcinoma cell invasiveness

Cancer associated fibroblasts (CAFs) are a major cellular component of the tumour stroma and have been shown to promote tumour cell invasion and disease progression. CAF-cancer cell interactions are bi-directional and occur via both soluble factor dependent and extracellular matrix (ECM) remodelling mechanisms, which are incompletely understood. Previously we developed the Tissue Roll for Analysis of Cellular Environment and Response (TRACER), a novel stacked paper tumour model in which cells embedded in a hydrogel are infiltrated into a porous cellulose scaffold that is then rolled around an aluminum core to generate a multi-layered 3D tissue. Here, we use the TRACER platform to explore the impact of CAFs derived from three different patients on the invasion of two head and neck squamous cell carcinoma (HNSCC) cell lines (CAL33 and FaDu). We find that co-culture with CAFs enhances HNSCC tumour cell invasion into an acellular collagen layer in TRACER and this enhanced migration occurs independently of proliferation. We show that CAF-enhanced invasion of CAL33 cells is driven by a soluble factor independent mechanism, likely involving CAF mediated ECM remodelling via matrix metalloprotenases (MMPs). Furthermore, we find that CAF-enhanced tumour cell invasion is dependent on the spatial pattern of collagen density within the culture. Our results highlight the utility of the co-culture TRACER platform to explore soluble factor independent interactions between CAFs and tumour cells that drive increased tumour cell invasion.

Evaluation of Proinflammatory, NF-kappaB Dependent Cytokines: IL-1α, IL-6, IL-8, and TNF-α in Tissue Specimens and Saliva of Patients with Oral Squamous Cell Carcinoma and Oral Potentially Malignant Disorders

Background: Oral squamous cell carcinoma (OSCC) is a life-threatening disease. It could be preceded by oral potentially malignant disorders (OPMDs). It was confirmed that chronic inflammation can promote carcinogenesis. Cytokines play a crucial role in this process. The aim of the study was to evaluate interleukin-1alpha (IL-1α), interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor alpha (TNF-α) in tissue specimens and saliva of patients with OSCC and OPMDs. Methods: Cytokines were evaluated in 60 tissue specimens of pathological lesions (OSCCs or OPMDs) and in 7 controls (normal oral mucosa, NOM) by immunohistochemistry and in saliva of 45 patients with OSCC or OPMDs and 9 controls (healthy volunteers) by enzyme-linked immunosorbent assays. Results: Immunohistochemical analysis revealed significantly higher expression of IL-8 in OSCC specimens and TNF-α in OSCCs and OPMDs with dysplasia as compared to NOM. Moreover, expression of TNF-α was significantly higher in oral leukoplakia and oral lichen planus without dysplasia, whereas expression of IL-8 only in oral leukoplakia without dysplasia in comparison with NOM. Salivary concentrations of all evaluated cytokines were significantly higher in patients with OSCC than in controls. Moreover, levels of IL-8 were significantly higher in saliva of patients with OPMDs with dysplasia as compared to controls and in OSCC patients as compared to patients with dysplastic lesions. There was also significant increase in salivary concentrations of IL-6, IL-8 and TNF-α in patients with OSCC as compared to patients with OPMDs without dysplasia. Conclusion: The study confirmed that proinflammatory, NF-kappaB dependent cytokines are involved in pathogenesis of OPMDs and OSCC. The most important biomarker of malignant transformation process within oral mucosa among all assessed cytokines seems to be IL-8. Further studies on a larger sample size are needed to corroborate these results.

CCL7 Signaling in the Tumor Microenvironment

The tumor microenvironment is the primary location in which tumor cells and the host immune system interact. There are many physiological, biochemical, cellular mechanisms in the neighbor of tumor which is composed of various cell types. Interactions of chemokines and chemokine receptors can recruit immune cell subsets into the tumor microenvironment. These interactions can modulate tumor progression and metastasis. In this chapter, we will focus on chemokine (C-C motif) ligand 7 (CCL7) that is highly expressed in the tumor microenvironment of various cancers, including colorectal cancer, breast cancer, oral cancer, renal cancer, and gastric cancer. We reviewed how CCL7 can affect cancer immunity and tumorigenesis by describing its regulation and roles in immune cell recruitment and stromal cell biology.

Immunomodulatory aspects in the progression and treatment of oral malignancy

Inflammation substantially affects the risk of oral malignancy. Pro-inflammatory cytokine, interferon (IFN)-γ, confers anti-tumor activity using several different mechanisms. Conversely, higher expression of interleukin (IL)-17 is associated with worse prognosis. Monocyte chemotactic protein (MCP)-1 correlates positively with poor long-term survival of head and neck squamous cell carcinoma (HNSCC) patients. IL-1α affects cancer associated fibroblasts and macrophages, and promote several malignant phenotypes including immune suppression. Some anti-inflammatory cytokines, including IL-10 and transforming growth factor (TGF)-β, relate to pro-tumoral activities. Among immune checkpoint modulators, programmed death (PD-)1 and PD-ligand (L)1 facilitate oral squamous cell carcinoma (OSCC) cell evasion from immune surveillance, and the expression status of these has a prognostic value. OSCCs contain tumor associated macrophages (TAMs) as major stromal cells of their tumor microenvironment. Among the two distinctive states, M2 macrophages support tumor invasion, metastasis and immune suppression. Crosstalk between TAMs and OSCC or cancer-associated fibroblasts (CAF) plays an important role in the progression of OSCC. Clinical trials with blocking antibodies against IL-1α or melanoma-associated antigens have been reported as therapeutic approaches against OSCCs. The most promising approach activating antitumor immunity is the blockade of PD-1/PD-L1 axis. Manipulating the polarization of pro-tumorigenic macrophages has been reported as a novel therapeutic approach.

MAPKAPK2 (MK2) inhibition mediates radiation-induced inflammatory cytokine production and tumor growth in head and neck squamous cell carcinoma

Radiation therapy (RT) is a cornerstone of treatment in the management of head and neck squamous cell carcinomas (HNSCC), yet treatment failure and disease recurrence are common. The p38/MK2 pathway is activated in response to cellular stressors, including radiation, and promotes tumor inflammation in a variety of cancers. We investigated MK2 pathway activation in HNSCC and the interaction of MK2 and RT in vitro and in vivo. We used a combination of an oropharyngeal SCC tissue microarray, HNSCC cell lines and patient-derived xenograft (PDX) tumor models to study the effect of RT on MK2 pathway activation and to determine how inhibition of MK2 by pharmacologic (PF-3644022) and genetic (siRNA) methods impacts tumor growth. We show that high phosphorylated MK2 (p-MK2) levels are associated with worsened disease specific survival in p16-negative HNSCC patients. RT increased p-MK2 in both p16-positive, HPV-positive and p16-negative, HPV-negative HNSCC cell lines. Pharmacologic inhibition or gene silencing of MK2 in vitro abrogated RT-induced increases in p-MK2; inflammatory cytokine expression and expression of the downstream MK2 target, heat shock protein 27 (HSP27); and markers of epithelial-to-mesenchymal transition. Mouse PDX models treated with a combination of RT and MK2 inhibitor experienced decreased tumor growth and increased survival. Our results suggest that MK2 is a potential prognostic biomarker for head and neck cancer and that MK2 pathway activation can mediate radiation resistance in HNSCC.

Oral cancer-associated fibroblasts predict poor survival: Systematic review and meta-analysis

OBJECTIVES

To perform systematic review and meta-analysis on correlations between cancer-associated fibroblasts (CAFs) and the risk of death for patients with oral squamous cell carcinoma.

SUBJECTS AND METHODS

English literature (1966-2018) was systematically analyzed for studies that immunohistochemically assessed CAF density by alpha-smooth muscle actin and presented 5 year survival rates by Kaplan-Meier plots. Mean age of patients, proportion of male/female patients, and male/female majority (>50% male/female patients) per study were also collected. Significance level for statistical models was p < 0.05.

RESULTS

Meta-analysis comprised 11 studies/1,040 patients. Univariate Cox regressions showed that high CAF density was a negative prognostic factor in studies with female and male majority [OR 5.329 (95% CI 3.223-8.811), p < 0.001, and OR 2.208 (95% CI 1.717-2.839), p < 0.001, respectively]. High CAF density with male majority was associated with a more favorable prognosis [OR 0.996 (95% CI 0.979-1.013), p < 0.001]. Multivariate Cox regressions showed that death risk was significantly higher among patients with high CAF density compared to low CAF [OR 2.741 (95% CI 2.220-3.384) p < 0.001]. High mean age and male proportion were significantly protective [OR 0.940 (95% CI 0.925-9.955), p < 0.001, OR 0.125 (95% CI 0.018-0.867), p = 0.035), respectively].

CONCLUSIONS

CAFs increased death risk, male majority, and higher mean age were protective. A clinically validated cutoff for CAF density could serve as a reliable prognostic tool.

Immunosuppressive Effect of Mesenchymal Stromal Cells is Enhanced by IL-1α from Oral Squamous Cell Carcinoma Cells

Background:

We have already reported that mouse Oral Squamous Carcinoma Cells (OSCCs) Sq-1979 specifically enhance the immunosuppressive activity of mesenchymal 10T1/2 cells via the functional soluble factor (s).

Objective:

In this report, we attempted to identify soluble factor(s) mediating the immunosuppression of Sq-1979 cells.

Methods:

L5-11 cells are a variant established from the metastatic lymph nodes of Sq-1979-implanted mice. Unlike parental Sq-1979 cells, however, L5-11 cells lack promotion of immunosuppressive activity in 10T1/2 cells. In order to identify cytokine mRNAs specifically expressed in Sq-1979 cells but not in L5-11 cells, cDNA microarray was performed. Conditioned medium from Sq-1979 cells (CM) was absorbed by several different neutralizing antibodies (abs) against the corresponding cytokines. The absorbed CM was then co-cultured with 10T1/2 cells and anti-CD3 antibody-stimulated mouse spleen cells. The Interferon (IFN) -γ producing capability of the stimulated spleen cells was evaluated using Enzyme-Linked Immunosorbent Assay (ELISA). By using a specific cytokine product instead of CM in this co-culture system the source of the immunosuppressive effect was identified.

Results:

The expression of Ccl2, Ccl7, Il1-α, IL1f6 and Il6 mRNAs was specifically elevated in Sq-1979 cells compared to L5-11 cells. The suppression of the IFN-γ producing capability of stimulated spleen cells in the co-culture system was specifically alleviated by absorbing the CM with anti-IL-1α ab. We further demonstrated that the immunosuppressive effect of CM in the co-culture system could be completely substituted by IL-1α protein (50 pmol/ ml).

Conclusion:

The immunosuppressive function of 10T1/2 cells is specifically promoted by IL-1α, secreted by Sq-1979 cells.

Cytoskeletal alteration modulates cancer cell invasion through RhoA-YAP signaling in stromal fibroblasts

Cancer-associated fibroblasts(CAFs) participate in carcinogenesis through interaction with cancer cells. This study aimed to investigate the mechanism of cytoskeletal alteration of CAFs and its role in invasion of oral squamous cell carcinoma(OSCC).Immortalized normal fibroblasts(hTERT-hNOFs) co-cultured with OSCC cells showed myofibroblastic and senescent phenotypes like CAFs. Thus, this study substituted hTERT-hNOFs for CAFs. Next, the cytoskeletal alteration and its molecular mechanism were investigated in hTERT-hNOFs co-cultured with OSCC. As results, we found that RhoA regulated cytoskeletal organization in fibroblasts surrounding OSCC cells. Furthermore, as a downstream transcriptional factor of RhoA, YAP was mainly localized in the nucleus of hTERT-hNOFs co-cultured with OSCC. Consequently, we examined whether nuclear YAP localization of fibroblasts could influence cancer progression. YAPS127A fibroblasts manifesting nuclear localization of YAP induced cytoskeletal alteration and increased gel contractility and matrix stiffness, and thereby enhances the invasiveness of OSCC cells. In conclusion, the modification of tumor microenvironment, such as cytoskeletal change and matrix remodeling via RhoA-YAP in CAFs, modulates OSCC invasion. These understandings will provide the development of novel approaches for CAFs-based cancer therapy.

Exogenous interleukin-1α signaling negatively impacts acquired chemoresistance and alters cell adhesion molecule expression pattern in colorectal carcinoma cells HCT116

Proinflammatory cytokine and chemokine signaling from the tumor microenvironment is thought to be crucial for developing and sustaining colorectal cancer by regulating a multitude of pathways associated with a variety of cellular mechanisms. Among these pathways there is acquired chemoresistance, which is usually a major obstacle in the way towards successful chemotherapeutic treatment of advanced colorectal cancer cases. Despite of an emerging body of data published on the role of cytokine signaling network in cancer, little is known about the effects of the upstream cytokine interleukin-1α (IL-1α) signaling to the cancer cells. In this study we have shown that the increase in exogenous IL-1α signaling increases chemosensitivity of both chemosensitive and chemoresistant colorectal cancer cell lines, treated with a widely used cytotoxic antimetabolite 5-fluorouracil (5-FU). This was a result of increased cell death but not of the changes in 5-FU-induced cell cycle arrest. Noticeably, combined exogenous IL-1α and 5-FU treatment had significant effects on the expression of cell adhesion molecules, suggesting a decrease in adhesion-dependent chemoresistance and, on the other hand, an increase in metastatic potential of the cells. These results lead to a conclusion that modulation of IL-1 receptor activity could have applications as a part of combination therapy for advanced and highly metastatic colorectal cancers.

The expression and correlation between chemokine CCL7 and ABCE1 in non-small cell lung cancer

Lung cancer is a malignant disease, and has the highest incidence and mortality worldwide. Lung cancer is also a popular subject in the field of cancer research. The molecular mechanisms of lung cancer development, invasion and metastasis need to be determined to prolong survival times and improve the quality of life. Recent studies have demonstrated that ATP-binding cassette sub-family E member 1 (ABCE1) is one of the factors that contributes to the development and metastasis of lung cancer, but the specific mechanism of this phenomenon remains unclear. A polymerase chain reaction microarray was used in the present study to screen for chemokine (C-C motif) ligand 7 (CCL7) expression in cell lines that highly expressed ABCE1, and the results showed that CCL7 was highly expressed in H1299 cells (P<0.01). The expression of CCL7 and ABCE1 in lung cancer tissues obtained from 30 patients with non-small cell lung cancer (NSCLC) was higher than that in adjacent normal lung tissues (P<0.01), and a positive correlation between the expression levels of the two genes in NSCLC was observed. These findings indicate that ABCE1 is involved in the development and progression of lung cancer through the CCL7 signaling pathway.

Perspectives of Immune Suppression in the Tumor Microenvironment Promoting Oral Malignancy

Introduction

In order to survive, cancers control immune systems and evade immune detection using mediators consisting of immune checkpoint molecules and cellular systems associated with immune suppression.

Methodology

During the development of cancer and chronic infections, the immune checkpoints and cellular components including regulatory T cells, myeloid derived suppressor cells and cancer associated fibroblasts are often enhanced as a mechanism of immune subversion and have therefore become very important therapeutic targets.

Conclusion

In this review, we will discuss the complexity of immune-suppressive mechanisms in the tumor milieu of cancers, including oral malignancy.

Crucial biological functions of CCL7 in cancer

Chemokine (C-C motif) ligand 7 (CCL7), a CC chemokine, is a chemotactic factor and attractant for various kinds of leukocytes, including monocytes and neutrophils. CCL7 is widely expressed in multiple cell types and can participate in anti-inflammatory responses through binding to its receptors to mediate the recruitment of immune cells. Abnormal CCL7 expression is associated with certain immune diseases. Furthermore, CCL7 plays a pivotal role in tumorigenesis. CCL7 promotes tumor progression by supporting the formation of the tumor microenvironment and facilitating tumor invasion and metastasis, although some studies have suggested that CCL7 has tumor suppressor effects. In this review, we summarize the currently available information regarding the influence of CCL7 on tumors.

Cancer-Associated Fibroblasts Drive Glycolysis in a Targetable Signaling Loop Implicated in Head and Neck Squamous Cell Carcinoma Progression

Despite aggressive therapies, head and neck squamous cell carcinoma (HNSCC) is associated with a less than 50% 5-year survival rate. Late-stage HNSCC frequently consists of up to 80% cancer-associated fibroblasts (CAF). We previously reported that CAF-secreted HGF facilitates HNSCC progression; however, very little is known about the role of CAFs in HNSCC metabolism. Here, we demonstrate that CAF-secreted HGF increases extracellular lactate levels in HNSCC via upregulation of glycolysis. CAF-secreted HGF induced basic FGF (bFGF) secretion from HNSCC. CAFs were more efficient than HNSCC in using lactate as a carbon source. HNSCC-secreted bFGF increased mitochondrial oxidative phosphorylation and HGF secretion from CAFs. Combined inhibition of c-Met and FGFR significantly inhibited CAF-induced HNSCC growth in vitro and in vivo (P < 0.001). Our cumulative findings underscore reciprocal signaling between CAF and HNSCC involving bFGF and HGF. This contributes to metabolic symbiosis and a targetable therapeutic axis involving c-Met and FGFR.Significance: HNSCC cancer cells and CAFs have a metabolic relationship where CAFs secrete HGF to induce a glycolytic switch in HNSCC cells and HNSCC cells secrete bFGF to promote lactate consumption by CAFs. Cancer Res; 78(14); 3769-82. ©2018 AACR.

Significance of stroma in biology of oral squamous cell carcinoma

The worldwide annual incidence of oral squamous cell carcinoma (OSCC) is over 300,000 cases with a mortality rate of 48%. This cancer type accounts for 90% of all oral cancers, with the highest incidence in men over 50 years of age. A significantly increased risk of developing OSCC exists among smokers and people who consume alcohol daily. OSCC is an aggressive cancer that metastasizes rapidly. Despite the development of new therapies in the treatment of OSCC, no significant increase in 5-year survival has been recorded in the past decades. The latest research suggests focus should be put on examining tumor stroma activation within OSCC, as the stroma may contain cells that can produce signal molecules and a microenvironment crucial for the development of metastases. The aim of this review is to provide an insight into the factors that activate OSCC stroma and hence faciliate neoplastic progression. It is based on the currently available data on the role and interaction between metalloproteinases, cytokines, growth factors, hypoxia factor and extracellular adhesion proteins in the stroma of OSCC and neoplastic cells. Their interplay is additionally presented using the Systems Biology Graphical Notation in order to sublimate the collected knowledge and enable the more efficient recognition of possible new biomarkers in the diagnostics and follow-up of OSCC or in finding new therapeutic targets.

CXCL1 induces senescence of cancer-associated fibroblasts via autocrine loops in oral squamous cell carcinoma

Cancer-associated fibroblasts (CAFs) have emerged as one of the main factors related to cancer progression, however, the conversion mechanism of normal fibroblasts (NOFs) to CAFs has not been well elucidated. The aim of this study was to investigate the underlying mechanism of CAF transformation from NOFs in oral squamous cell carcinoma (OSCC). This study found that NOFs exposed to OSCC cells transformed to senescent cells. The cytokine antibody array showed the highest secretion levels of IL-6 and CXCL1 in NOFs co-cultured with OSCC cells. Despite that both IL-6 and CXCL1 induced the senescent phenotype of CAFs, CXCL1 secretion showed a cancer-specific response to transform NOFs into CAFs in OSCC, whereas IL-6 secretion was eventuated by common co-culture condition. Further, CXCL1 was released from NOFs co-cultured with OSCC cells, however, CXCL1 was undetectable in mono-cultured NOFs or co-cultured OSCC cells with NOFs. Taken together, this study demonstrates that CXCL1 can transform NOFs into senescent CAFs via an autocrine mechanism. These data might contribute to further understanding of CAFs and to development of a potential therapeutic approach targeting cancer cells-CAFs interactions.