Interaction between oral squamous cell carcinoma cells and fibroblasts through TGF-β1 mediated by podoplanin

Crosstalk between CAFs and tumour cells in head and neck cancer

Head and neck squamous cell carcinomas (HNSCCs) are amongst the most aggressive, complex, and heterogeneous malignancies. The standard of care treatments for HNC patients include surgery, radiotherapy, chemotherapy, or their combination. However, around 50% do not benefit while suffering severe toxic side effects, costing the individuals and society. Decades have been spent to improve HNSCC treatment outcomes with only limited success. Much of the research in HNSCC treatment has focused on understanding the genetics of the HNSCC malignant cells, but it has become clear that tumour microenvironment (TME) plays an important role in the progression as well as treatment response in HNSCC. Understanding the crosstalk between cancer cells and TME is crucial for inhibiting progression and treatment resistance. Cancer-associated fibroblasts (CAFs), the predominant component of stroma in HNSCC, serve as the primary source of extra-cellular matrix (ECM) and various pro-tumoral composites in TME. The activation of CAFs in HNSCC is primarily driven by cancer cell-secreted molecules, which in turn induce phenotypic changes, elevated secretive status, and altered ECM production profile. Concurrently, CAFs play a pivotal role in modulating the cell cycle, stemness, epithelial-mesenchymal transition (EMT), and resistance to targeted and chemoradiotherapy in HNSCC cells. This modulation occurs through interactions with secreted molecules or direct contact with the ECM or CAF. Co-culture and 3D models of tumour cells and other TME cell types allows to mimic the HNSCC tumour milieu and enable modulating tumour hypoxia and reprograming cancer stem cells (CSC). This review aims to provide an update on the development of HNSCC tumour models comprising CAFs to obtain better understanding of the interaction between CAFs and tumour cells, and for providing preclinical testing platforms of current and combination with emerging therapeutics.

PDPN+ CAFs facilitate the motility of OSCC cells by inhibiting ferroptosis via transferring exosomal lncRNA FTX

Cancer-associated fibroblasts (CAFs) are abundant and heterogeneous in tumor microenvironment (TME). Cross-talk between cancer cells and CAFs results in cancer progression. Here, we demonstrated that a distinct cancer-associated fibroblasts subset with podoplanin (PDPN) positive expression (PDPN+ CAFs) was correlated with poor survival in oral squamous cell carcinoma (OSCC). PDPN+ CAFs promoted the progression of OSCC by transferring exosomal lncRNA FTX to OSCC cells. Mechanically, FTX bound to flap endonuclease-1 (FEN1), forming an RNA‒protein complex. FTX enhanced promoter demethylation of FEN1 by recruiting ten-eleven translocation-2 (TET2). In addition, FTX/FEN1 axis promoted OSCC cells motility by inhibiting ferroptosis. In xenograft experiments, RSL-3, a ferroptosis-inducing agent, suppressed the tumorigenesis potential of FEN1-overexpressed OSCC cells. Furthermore, Acyl-CoA synthetase long-chain family member 4 (ACSL4) was confirmed to participate in the motility promotion induced by FEN1 overexpression. FEN1 could bind to promoter region of ACSL4 and then inhibit ferroptosis in OSCC cells. Our study reveals that PDPN+ CAFs promote the invasiveness of OSCC cells by inhibiting ferroptosis through FTX/FEN1/ACSL4 signaling cascade. PDPN+ CAFs may serve as a novel potential therapeutic target for OSCC.

Transcutaneous carbon dioxide application suppresses the expression of cancer-associated fibroblasts markers in oral squamous cell carcinoma xenograft mouse model

Oral squamous cell carcinoma (OSCC) is the most common head and neck cancer. Cancer-associated fibroblasts (CAFs) are the main stromal cells in the tumor microenvironment (TME). As CAFs promote tumor progression and hypoxia in the TME, regulating the conversion of normal fibroblasts (NFs) into CAFs is essential for improving the prognosis of patients with OSCC. We have previously reported the antitumor effects of transcutaneous carbon dioxide (CO2) application in OSCC. However, the effects of reducing hypoxia in the TME remain unclear. In this study, we investigated whether CO2 administration improves the TME by evaluating CAFs marker expression. Human OSCC cells (HSC-3) and normal human dermal fibroblasts (NHDF) were coinjected subcutaneously into the dorsal region of mice. CO2 gas was applied twice a week for 3 weeks. The tumors were harvested six times after transcutaneous CO2 application. The expression of CAFs markers (α-SMA, FAP, PDPN, and TGF-β) were evaluated by using real-time polymerase chain reaction and immunohistochemical staining. The expression of α-SMA, FAP, PDPN, and TGF-β was significantly increased over time after co-injection. In the CO2-treated group, tumor growth was significantly suppressed after treatment initiation. In addition, the mRNA expression of these markers was significantly inhibited. Furthermore, immunohistochemical staining revealed a significant decrease in the protein expression of all CAFs markers in the CO2-treated group. We confirmed that transcutaneous CO2 application suppressed CAFs marker expression and tumor growth in OSCC xenograft mouse model.

Heterogeneity of cancer-associated fibroblasts in head and neck squamous cell carcinoma: opportunities and challenges

Head and neck squamous cell carcinoma (HNSCC) is among the most severe and complex malignant diseases with a high level of heterogeneity and, as a result, a wide range of therapeutic responses, regardless of clinical stage. Tumor progression depends on ongoing co-evolution and cross-talk with the tumor microenvironment (TME). In particular, cancer-associated fibroblasts (CAFs), embedded in the extracellular matrix (ECM), induce tumor growth and survival by interacting with tumor cells. Origin of CAFs is quite varied, and the activation patterns of CAFs are also heterogeneous. Crucially, the heterogeneity of CAFs appears to play a key role in ongoing tumor expansion, including facilitating proliferation, enhancing angiogenesis and invasion, and promoting therapy resistance, through the production of cytokines, chemokines, and other tumor-promotive molecules in the TME. This review describes the various origin and heterogeneous activation mechanisms of CAFs, and biological heterogeneity of CAFs in HNSCC is also included. Moreover, we have highlighted versatility of CAFs heterogeneity in HNSCC progression, and have discussed different tumor-promotive functions of CAFs respectively. In the future, it is a promising strategy for the therapy of HNSCC that specifically targeting tumor-promoting CAF subsets or the tumor-promoting functional targets of CAFs.

Cancer-Associated Fibroblasts: Master Tumor Microenvironment Modifiers

Cancer cells rely on the tumor microenvironment (TME), a composite of non-malignant cells, and extracellular matrix (ECM), for survival, growth, and metastasis. The ECM contributes to the biomechanical properties of the surrounding tissue, in addition to providing signals for tissue development. Cancer-associated fibroblasts (CAFs) are stromal cells in the TME that are integral to cancer progression. Subtypes of CAFs across a variety of cancers have been revealed, and each play a different role in cancer progression or suppression. CAFs secrete signaling molecules and remodel the surrounding ECM by depositing its constituents as well as degrading enzymes. In cancer, a remodeled ECM can lead to tumor-promoting effects. Not only does the remodeled ECM promote growth and allow for easier metastasis, but it can also modulate the immune system. A better understanding of how CAFs remodel the ECM will likely yield novel therapeutic targets. In this review, we summarize the key factors secreted by CAFs that facilitate tumor progression, ECM remodeling, and immune suppression.

Loss of exosomal miR-200b-3p from hypoxia cancer-associated fibroblasts promotes tumorigenesis and reduces sensitivity to 5-Flourouracil in colorectal cancer via upregulation of ZEB1 and E2F3

Hypoxia-mediated tumor progression is a major clinical challenge in human cancers including colorectal cancer (CRC). In addition, exosome-mediated transfer of miRNAs from cancer-associated fibroblasts (CAFs) to cancer cells could promote tumor progression. However, the mechanisms by which hypoxia CAFs promotes CRC progression remain largely unknown. CAFs and normal fibroblasts (NFs) were isolated from CRC tissues and adjacent normal tissues. Next, exosomes were isolated from the supernatant of CAFs that cultured under normoxia (CAFs-N-Exo) and hypoxia (CAFs-H-Exo). RNA-sequencing was then performed to identify differentially expressed miRNAs (DEMs) between CAFs-N-Exo and CAFs-H-Exo. Compared with exosomes derived from normoxia CAFs, exosomes derived from hypoxic CAFs were able to promote CRC cell proliferation, migration, invasion, stemness and reduce the sensitivity of CRC cells to 5-fluorouracil (5-FU). In addition, miR-200b-3p levels were dramatically decreased in exosomes derived from hypoxic CAFs. Remarkably, increasing exosomal miR-200b-3p in hypoxic CAFs reversed the promoting effects of hypoxic CAFs on CRC cell growth in vitro and in vivo. Furthermore, miR-200b-3p agomir could inhibit CRC cell migration, invasion, stemness and increase the sensitivity of SW480 cells to 5-FU via downregulating ZEB1 and E2F3. Collectively, loss of exosomal miR-200b-3p in hypoxia CAFs could contribute to CRC progression via upregulation of ZEB1 and E2F3. Thus, increasing exosomal miR-200b-3p might serve as an alternative approach for the treatment of CRC.

LRRC superfamily expression in stromal cells predicts the clinical prognosis and platinum resistance of ovarian cancer

BACKGROUND

Leucine-rich repeat sequence domains are known to mediate protein‒protein interactions. Recently, some studies showed that members of the leucine rich repeat containing (LRRC) protein superfamily may become new targets for the diagnosis and treatment of tumours. However, it is not known whether any of the LRRC superfamily genes is expressed in the stroma of ovarian cancer (OC) and is associated with prognosis.

METHODS

The clinical data and transcriptional profiles of OC patients from the public databases TCGA (n = 427), GTEx (n = 88) and GEO (GSE40266 and GSE40595) were analysed by R software. A nomogram model was also generated through R. An online public database was used for auxiliary analysis of prognosis, immune infiltration and protein‒protein interaction (PPI) networks. Immunohistochemistry and qPCR were performed to determine the protein and mRNA levels of genes in high-grade serous ovarian cancer (HGSC) tissues of participants and the MRC-5 cell line induced by TGF-β.

RESULTS

LRRC15 and LRRC32 were identified as differentially expressed genes from the LRRC superfamily by GEO transcriptome analysis. PPI network analysis suggested that they were most enriched in TGF-β signalling. The TCGA-GTEx analysis results showed that only LRRC15 was highly expressed in both cancer-associated fibroblasts (CAFs) and the tumour stroma of OC and was related to clinical prognosis. Based on this, we developed a nomogram model to predict the incidence of adverse outcomes in OC. Moreover, LRRC15 was positively correlated with CAF infiltration and negatively correlated with CD8 + T-cell infiltration. As a single indicator, LRRC15 had the highest accuracy (AUC = 0.920) in predicting the outcome of primary platinum resistance.

CONCLUSIONS

The LRRC superfamily is related to the TGF-β pathway in the microenvironment of OC. LRRC15, as a stromal biomarker, can predict the clinical prognosis of HGSC and promote the immunosuppressive microenvironment. LRRC15 may be a potential therapeutic target for reversing primary resistance in OC.

Loss of exosomal micro-RNA-200b-3p from hypoxia cancer-associated fibroblasts reduces sensitivity to 5-flourouracil in colorectal cancer through targeting high-mobility group box 3

Hypoxia-mediated tumor progression is a major problem in colorectal cancer (CRC). MicroRNA (miR)-200b-3p can attenuate tumorigenesis in CRC, while exosomal miRNAs derived from cancer-associated fibroblasts (CAFs) can promote cancer progression. Nevertheless, the function of exosomal miR-200b-3p derived from CAFs in CRC remains unclear. In this study, CAFs and normal fibroblasts (NFs) were isolated from CRC and adjacent normal tissues. Next, exosomes were isolated from the supernatants of CAFs cultured under normoxia and hypoxia. Cell viability was tested using the cell counting kit-8 assay, and flow cytometry was used to assess cell apoptosis. Cell invasion and migration were evaluated using the transwell assay. Dual-luciferase was used to investigate the relationship between miR-200b-3p and high-mobility group box 3 (HMBG3). Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was performed to determine the miR-200b-3p and HMBG3 level. Our results found that the miR-200b-3p level was sharply reduced in CRC tissues compared to adjacent normal tissues. Additionally, the miR-200b-3p level was reduced in exosomes derived from hypoxic CAFs compared to exosomes derived from CAFs under normoxia. Exosomes derived from hypoxic CAFs weakened the sensitivity of CRC cells to 5-fluorouracil (5-FU) compared to hypoxic CAFs-derived exosomes. However, hypoxic CAFs-derived exosomes with upregulated miR-200b-3p increased the sensitivity of CRC cells to 5-fluorouracil (5-FU) compared to hypoxic CAFs-derived exosomes. In addition, HMBG3 was identified as the downstream target of miR-200b-3p in CRC cells, and its overexpression partially reversed the anti-tumor effect of the miR-200b-3p agomir on CRC via the mediation of the β-catenin/c-Myc axis. Furthermore, compared to exosomes derived from normoxia CAFs, exosomes derived from hypoxic CAFs weakened the therapeutic effects of 5-FU on CRC in vivo via the upregulation of HMGB3 levels. Collectively, the loss of exosomal miR-200b-3p in hypoxia CAFs reduced the sensitivity to 5-FU in CRC by targeting HMGB3. Thus, our research outlines a novel method for the treatment of CRC.

Cancer associated fibroblasts secreted exosomal miR-1290 contributes to prostate cancer cell growth and metastasis via targeting GSK3β

Cancer-associated fibroblasts (CAFs) play crucial roles in mediating tumor growth and metastasis via transferring exosomes to neighboring cells, whereas the mechanisms by which CAFs regulate the tumorgenesis of prostate cancer (PC) remain largely unknown. In this study, CAFs and normal fibroblasts (NFs) were isolated from PC tissues and adjacent normal tissues, respectively. Exosomes (NFs-Exo and CAFs-Exo) were then isolated from the supernatant of NFs and CAFs. Next, the differentially expressed miRNAs (DEMs) between NFs-Exo and CAFs-Exo were identified using RNA-sequencing. Cell viability, migration and invasion were detected with CCK-8 and Transwell assays. Protein expression was measured with western blot. We found that CAFs-Exo remarkably enhanced PC cell migration, invasion, stemness, epithelial-mesenchymal transition (EMT) and metastasis. Significantly, miR-1290 level was upregulated in CAFs-Exo compared to NFs-Exo. In addition, CAFs could transfer exosomes to PC cells, resulting in a marked increase of miR-1290 level in cells. Moreover, exosomal miR-1290 could inhibit GSK3β/β-catenin signaling by binding with the downstream target GSK3β mRNA. Meanwhile, miR-1290 antagomir notably reversed the effects of CAFs-Exo on PC cells through activating GSK3β/β-catenin signaling. Collectively, exosomal miR-1290 from CAFs could promote PC cell growth and metastasis via inhibiting GSK3β/β-catenin signaling, suggesting that miR-1290 may serve as potential therapeutic target for the treatment of PC.

TGFβ activating integrins β6 and β8 are dysregulated in inflammatory skin disease and cutaneous melanoma

BACKGROUND

Integrins avβ6 and avβ8 are expressed by keratinocytes and transactivate latent TGFβ. In a murine model, integrin mediated activation of TGFβ has been shown to be critical in maintaining skin homeostasis, specifically playing roles in epidermal retention of Langerhans cells and resident memory cells T cells (Trm).

OBJECTIVE

We examine expression of Integrins β6 and β8 in human skin, inflammatory skin disease, benign nevi, and melanoma and hypothesize that integrin expression is dysregulated in disease.

METHODS

Using immunohistochemistry, we stained tissue from normal human skin (n = 8), psoriasis (n = 6), atopic dermatitis (n = 6), lichen planus (n = 5), benign nevi (n = 24), and melanoma (n = 25) with anti-integrin β6 and anti-integrin β8 to survey expression pattern. We also performed a retrospective chart review in the melanoma cohort to examine if integrin β6 and β8 expression was associated with increased Breslow depth and worse prognostic staging.

RESULTS

Here, we show that human keratinocytes express integrins β6 and β8, similar to murine keratinocytes. We also found that inflammatory skin conditions have increased Integrin β6, but not Integrin β8 expression. Furthermore, we identified that melanomas have greatly increased expression of integrin β8 compared to nevi. Additionally, high expression of integrin β8 was correlated with greater Breslow depth at diagnosis and with worse prognostic staging.

CONCLUSION

These findings demonstrate that like murine keratinocytes, human keratinocytes express integrin β6 and β8 under steady state conditions. Moreover, altered integrin expression may participate in the development or maintenance of cutaneous inflammation as well as tumor immune evasion.

Roles of Podoplanin in Malignant Progression of Tumor

Podoplanin (PDPN) is a cell-surface mucin-like glycoprotein that plays a critical role in tumor development and normal development of the lung, kidney, and lymphatic vascular systems. PDPN is overexpressed in several tumors and is involved in their malignancy. PDPN induces platelet aggregation through binding to platelet receptor C-type lectin-like receptor 2. Furthermore, PDPN modulates signal transductions that regulate cell proliferation, differentiation, migration, invasion, epithelial-to-mesenchymal transition, and stemness, all of which are crucial for the malignant progression of tumor. In the tumor microenvironment (TME), PDPN expression is upregulated in the tumor stroma, including cancer-associated fibroblasts (CAFs) and immune cells. CAFs play significant roles in the extracellular matrix remodeling and the development of immunosuppressive TME. Additionally, PDPN functions as a co-inhibitory molecule on T cells, indicating its involvement with immune evasion. In this review, we describe the mechanistic basis and diverse roles of PDPN in the malignant progression of tumors and discuss the possibility of the clinical application of PDPN-targeted cancer therapy, including cancer-specific monoclonal antibodies, and chimeric antigen receptor T technologies.

The diverse role of oral fibroblasts in normal and disease

Fibroblasts are the major cellular component of the connective tissue. They differ both structurally and functionally based on their location. The oral fibroblasts vary from the dermal fibroblasts in their origin, properties and also functions. These cells play an important role in wound healing, tumor progression and metastasis, allergic reactions. In this review, the various functions of the oral fibroblasts are discussed in detail.

ERK-mediated upregulation of matrix metalloproteinase-2 promotes the invasiveness in human oral squamous cell carcinoma (OSCC)

BACKGROUND

Loco-regional invasion is commonly found in oral squamous cell carcinoma (OSCC) and is associated with its poor survival rate. Matrix metalloproteinase-2 (MMP-2) has been implicated in OSCC progression, but its regulation is poorly understood.

MATERIALS AND METHODS

Here, one hundred twenty-seven different post-operated human oral cancer tissue samples were analyzed. The messenger RNA (mRNA) expression, protein expression, and MMP-2 activity and MT1-MMP, TIMP-2, and TFs (NFκB, AP1, Sp1, and Twist) were observed semi-quantitative RT-PCR, western blotting, and gelatin zymography. In addition, OSCC derived Cal-27, SCC4/9 cells, photochemical ECGC, and MAPK-pathway inhibitor PD98059 were utilized for in vitro testing and wound healing assay.

RESULT

s: Increased protein and activity level of MMP-2 was detected in non-invasive (N₀) and invasive (N_1-3) oral tumors as compared to the control (adjacent normal) samples. MMP-2 protein and mRNA expression were positively associated with the TFs and MT1-MMP, negatively associated with TIMP-2 expression. Similarly, the MMP-2 expression/activity was related to several signal-transduction pathways like ERK1/2 and wnt-β-catenin pathways. Treatment of ECGC/MEK inhibitor (PD98059) diminished MMP-2 activity and invasion/migration potential in OSCC.

CONCLUSION

Our research suggests that the ERK1/2 driven overexpression/activation of MMP-2 was linked with the overall OSCC invasion and metastasis. Treatment of MEK inhibitor (PD98059) and ECGC diminished MMP-2 activity and thus could be exploited as a therapeutic strategy to control the invasive OSCC.

Podoplanin Expression in Odontogenic Keratocysts Associated or not Associated With Nevoid Basal Cell Carcinoma Syndrome

BACKGROUND

Podoplanin is a transmembrane glycoprotein expressed on various normal or neoplastic cells. Some studies have shown that podoplanin promotes the migration and invasion of tumor cells. This study evaluated a podoplanin expression in Odontogenic Keratocysts (OKs) associated or not associated with Nevoid Basal Cell Carcinoma Syndrome (NBCCS) and in Orthokeratinized Odontogenic Cysts (OOCs).

MATERIALS AND METHODS

A total of 50 lesions were obtained in this study, 28 OKs, 18 OKs associated with NBCCS, and 4 OOCs. Immunohistochemical expression of podoplanin in epithelial cells was evaluated using the following score: (a) intensity of immunostaining: (0: absent, 1: weak, 2: moderate, 3: strong, and 4: very strong) and (b) number of positively cells (0: 0%, 1: <25%, 2: 25% to 50%, 3: 50% to 75%, and 4: >75%). The final score was determined by adding the scores of a and b and ranged from 0 to 8 (0: absent, 1 to 4: weak, and 5 to 8: strong).

RESULTS

Podoplanin expression was significantly stronger in the basal layer OKs and NBCCS lesions. Further, podoplanin expression was the highest in the suprabasal layer of NBCCS lesions, followed by the suprabasal layers of OK and OOC lesions.

CONCLUSIONS

Podoplanin expression is different in lesions of different biological behaviors. Podoplanin seems to play a role in cell proliferation and migration.

3D Bioprinting for In Vitro Models of Oral Cancer: Toward Development and Validation

The tumor microenvironment (TME) of oral carcinomas has highly complex contents and a dynamic nature which is difficult to study using oversimplified two-dimensional (2D) cell culture systems. By contrast, three dimensional (3D) in vitro models such as spheroids, organoids, and scaffold-based constructs have been able to replicate tumors three-dimensionality and have allowed a better understanding of the role of various microenvironmental cues in the initiation and progression of cancer. However, the heterogeneity of TME cannot be fully reproduced by these traditional tissue engineering strategies since they are unable to control the organization of multiple cell types in a complex architecture. 3D bioprinting is an emerging field that can be leveraged to produce biomimetic and complex tissue structures. Bioprinting allows for controllable and precise placement of multicomponent bioinks composed of multiple biomaterials, different types of cells, and soluble factors according to the natural compartments of the target tissue, aiming to reproduce the equivalent of the complex tissue. As such, 3D bioprinting provides a unique opportunity to fabricate in vitro tumor models with a complexity similar to that of the in vivo oral carcinoma. This will facilitate a thorough investigation of cellular physiology, cancer progression, and anti-cancer drug screening with unprecedented control and reproducibility. In this review, we discuss the role of 3D bioprinting in reconstituting oral cancer, the prospects of application to fill the literature gap, and the challenges that need to be addressed in order to exploit this emerging technology for future work in oral cancer research.

Biological effects of exosome derived from Cal27 on normal human gingival fibroblasts

OBJECTIVES

The proliferation, migration capacity, and expression of activation-related proteins of NHGFs+Cal27-exo were determined by coculturing Cal27 exosome (Cal27-exo) with normal human gingival fibroblasts (NHGFs) to explore the effects of Cal27-exo on the activation and biological behavior of NHGFs.

METHODS

Cal27-exo was extracted using supercentrifugation, and exosomes were identified using Western blot, transmission electron microscopy (TEM), and particle size detection. Cal27-exo was cocultured with NHGFs to detect the uptake of Cal27-exo by NHGFs, and the proliferation and migration capacity of NHGFs+Cal27-exo were detected using CCK8 and wound healing tests, respectively. The expression levels of NHGF activation-related proteins, i.e., matrix metalloproteinase-9 (MMP-9), fibroblast-activating protein (FAP), alpha smooth muscle actin (αSMA), and transforming growth factor-β (TGF-β), were detected using real-time quantitative polymerase chain reaction (qRT-PCR).

RESULTS

Cal27-exo was extracted u-sing supercentrifugation, and Western blot showed the positive expression levels of Alix and CD63. TEM showed that Cal27-exo had a circular double-layer vesicle. The particle size was between 30 and 150 nm. Cal27-exo labeled with PKH67 entered NHGFs after the coculture method. The wound healing test showed that the migration capacity of NHGFs+Cal27-exo was stronger after the scratch compared with that of NHGFs. CCK8 results showed that the proliferation activity of NHGFs+Cal27-exo was enhanced. qRT-PCR results showed that the MMP-9 levels of NHGFs+Cal27-exo were upregulated, whereas the TGF-β and αSMA mRNA levels of NHGFs+Cal27-exo were downregulated (P<0.05).

CONCLUSIONS

The proliferation and migration ability of NHGFs+Cal27-exo are enhanced, and the mRNA expression of related proteins is changed. Cal27-exo can activate NHGFs, which suggests that Cal27-exo has potential significance in tumor invasion and metastasis.

Mechanism of tumour microenvironment in the progression and development of oral cancer

Oral cancer has been a major problem all across the globe, majorly in the developing countries. With a growing emphasis in the field of cancer research, the contribution of the tumour microenvironment has been gaining a lot of importance in identifying the role of components other than the tumour cells that cause the development of cancer, thus changing the outlook. The review will shed light on the studies that describe the role of microenvironment, its components as well as summarize the studies related to their mechanism in the progression of oral cancer. The literature for the review was derived mainly from Google Scholar and PubMed, in particular concentrating on the most recent papers published in 2019 and 2020, by using the keywords "Cancer, Oral Cancer, Metastasis, OSCC, Tumour microenvironment, CAFs, ECM, Cytokines, Hypoxia, Therapeutics targeting the microenvironment". The study provides insight into the world of micro-environmental regulation of oral cancer, the mechanism by which they interact and how to exploit it as a potential therapeutic haven for treating the disease. The components Cancer-Associated Fibroblasts (CAFs), Tumour-associated Macrophages (TAMs), Tumour-associated neutrophils (TANs), Hypoxic environment, myeloid-derived stem cells (MDSCs) and T regulatory (Tregs) cells and underlying mechanisms that control them will be the targets of study to understand the microenvironment.

TGF-β1 and IL-17A comediate the protumor phenotype of neutrophils to regulate the epithelial-mesenchymal transition in oral squamous cell carcinoma

BACKGROUND

The role of neutrophils in cancer has been the subject of intense research in recent years. One major theme that has emerged is that not all neutrophils are equal in the field of cancer. However, it remains unclear what induces the protumorigenic or antitumorigenic phenotype predominate in tumor. Therefore, this study aimed to investigate what factors induce which of these two phenotypes of neutrophil predominate in OSCC and to explore the role of neutrophil polarization on tumor.

METHODS

Immunofluorescence and immunohistochemistry staining were used to observe neutrophil infiltration and the expression of TGF-β1 and IL-17A in OSCC tissues. Recombinant human TGF-β1 and IL-17A were used to modulate neutrophil polarization. OSCC cell (SCC9 and SAS cell lines) migration, proliferation, invasion, stemness, and EMT were analyzed after treatment with conditioned medium from TGF-β1/IL-17A-activated neutrophils. The levels of neutrophil-associated markers in OSCC tissues and peripheral blood were examined by immunofluorescence staining and quantitative PCR.

RESULTS

Our data showed neutrophil infiltration and elevated expression of TGF-β1 and IL-17A in OSCC tissues. The cooperative effect of TGF-β1 and IL-17A promoted neutrophils to take on a protumor phenotype in vitro. TGF-β1/IL-17A-activated neutrophils remarkably induced cell migration, proliferation, invasion, stemness, and EMT in OSCC cells. Additionally, OSCC patients showed increased expression of MMP9 and decreased expression of CCL3 in circulating neutrophils.

CONCLUSION

TGF-β1 and IL-17A cooperated to augment the protumor functions of neutrophils, thereby promoting the progression of OSCC cells. In addition, the combination of neutrophil-associated markers may serve as a predictive method to screen for patients with OSCC.

Exosomal LncRNA LINC00659 transferred from cancer-associated fibroblasts promotes colorectal cancer cell progression via miR-342-3p/ANXA2 axis

Background

Cancer-associated fibroblasts (CAFs) play a pivotal role in regulating tumor progression by transferring exosomes to adjacent cells. Our aim was to clarify the role of LINC00659 encapsulated in CAFs-derived exosomes (CAFs-exo) in colorectal cancer (CRC).

Methods

CAFs and normal fibroblasts (NFs) were isolated and cultured. CAFs-exo and NFs-derived exosomes (NFs-exo) were characterized by transmission electron microscope and Western blot. The mRNA level of LINC00659 in CAFs-exo and NFs-exo were measured. Then we analyzed cell proliferation by CCK-8 and clone formation assay, cell migration by cell scratch, and cell invasion by Transwell. Epithelial mesenchymal transformation (EMT) related markers E-cadherin, N-cadherin, Vimentin and Snail-1 expressions were assessed by Western blot. The binding of LINC00659 and miR-342-3p, miR-342-3p and ANXA2 were analyzed by dual-luciferase reporter gene assay.

Results

CAFs and NFs showed a spindle-like morphology. CAFs-exo promoted CRC cell proliferation, migration, invasion and EMT progression. The expression of LINC00659 in CAF-derived exosomes was significantly increased, and fibroblasts could transfer exosomal LINC00659 to CRC cells. We further revealed that transfection of miR-342-3p mimic or sh-ANXA2 could obviously reverse the promotion effect of exosomal LINC00659 on CRC progression. Functional studies reveal that LINC00659 is transferred from CAFs to the cancer cells via exosomes, where it promotes CRC cell proliferation, invasion, migration and EMT progression in vitro. Mechanistically, LINC00659 interacts directly with miR-342-3p to increase ANXA2 expression in CRC cells.

Conclusion

Collected evidence supported that CAFs-derived exosomal LINC00659 promotes CRC cell proliferation, invasion and migration via miR-342-3p/ANXA2axis.

Effects of Maackia amurensis seed lectin (MASL) on oral squamous cell carcinoma (OSCC) gene expression and transcriptional signaling pathways

PURPOSE

Oral cancer causes over 120,000 deaths annually and affects the quality of life for survivors. Over 90% of oral cancers are derived from oral squamous cell carcinoma cells (OSCCs) which are generally resistant to standard cytotoxic chemotherapy agents. OSCC cells often exhibit increased TGFβ and PDPN receptor activity compared to nontransformed oral epithelial cells. Maackia amurensis seed lectin (MASL) can target the PDPN receptor and has been identified as a novel agent that can be used to treat oral cancer. However, mechanisms by which MASL inhibits OSCC progression are not yet clearly defined.

METHODS

Here, we performed cell migration and cytotoxicity assays to assess the effects of MASL on OSCC motility and viability at physiologically relevant concentrations. We then performed comprehensive transcriptome analysis combined with transcription factor reporter assays to investigate the how MASL affects OSCC gene expression at these concentration. Key data were then confirmed by western blotting to evaluate the effects of MASL on gene expression and kinase signaling activity at the protein level.

RESULTS

MASL significantly affected the expression of about 27% of approximately 15,000 genes found to be expressed by HSC-2 cells used to model OSCC cells in this study. These genes affected by MASL include members of the TGFβ-SMAD, JAK-STAT, and Wnt-βCTN signaling pathways. In particular, MASL decreased expression of PDPN, SOX2, and SMAD5 at the RNA and protein levels. MASL also inhibited SMAD and MAPK activity, and exhibited potential for combination therapy with doxorubicin and 5-fluorouracil.

CONCLUSIONS

Taken together, results from this study indicate that MASL decreases activity of JAK-STAT, TGFβ-SMAD, and Wnt-βCTN signaling pathways to inhibit OSCC growth and motility. These data suggest that further studies should be undertaken to determine how MASL may also be used alone and in combination with other agents to treat oral cancer.

Portrait of a CAF: The story of cancer-associated fibroblasts in head and neck cancer

Complex interactions take place during cancer formation and progression. In this regard, there has been increasing focus on the non-malignant cells that make up the tumour microenvironment (TME), and how they interact with malignant tumour cells. TME is highly heterogeneous and has a major influence on tumour behaviour and therapy response. Cancer-associated fibroblasts (CAFs), one of the main components of the TME, establish dangerous liaisons with cancer cells and other components of the TME to shape a tumour-supportive environment in many types of cancer. Head and neck squamous cell carcinoma (HNSCC) encompass the malignant neoplasms arising from the mucosal lining of the oral cavity, pharynx and larynx. The TME of HNSCC contributes to tumour progression and this stromal compartment may be an interesting target for treatment. There is an emerging picture of the behaviour of CAFs in HNSCC; how they affect and are affected by the TME. We aim to summarise and discuss the current understanding of CAFs in head and neck cancer, exploring CAF activation and heterogeneity, and interaction with cancer cells and other cells within the TME.

MiR-210 in exosomes derived from CAFs promotes non-small cell lung cancer migration and invasion through PTEN/PI3K/AKT pathway

OBJECTIVE

Cancer-associated fibroblasts (CAFs) function as a crucial factor in tumor progression by carrying exosomes to neighboring cells. This study was assigned to expound the underlying mechanism of CAFs-derived exosomal miR-210 in non-small cell lung cancer (NSCLC) progression.

METHOD

CAFs and normal fibroblasts (NFs) were isolated and identified. Exosomes secreted from CAFs and NFs were isolated to analyze their effects on tumor volume and epithelial-mesenchymal transition (EMT). Exosomal miR-210 expression level was measured. The effects of exosomal miR-210 and UPF1 on cell viability, EMT, PTEN/PI3K/AKT signal pathway were determined. Dual-luciferase reporter gene assay was utilized to validate the binding of UPF1 to miR-210.

RESULTS

CAFs-derived exosomes (CAFs-exo) were successfully extracted and proven to be uptake by lung cancer cells. Up-regulated expression level of miR-210 was found in CAFs-exo, which was then proved to enhance cell migration, proliferation, invasion abilities and EMT in NSCLC cells. Overexpression of miR-210 can also inhibit UPF1 and PTEN, but activate the PTEN/PI3K/AKT pathway. UPF1 was a target gene of miR-210. MiR-210 can up-regulate UPF1 expression level to activate PTEN/PI3K/AKT pathway.

CONCLUSION

MiR-210 secreted by CAFs-exo could promote EMT by targeting UPF1 and activating PTEN/PI3K/AKT pathway, thereby promoting NSCLC migration and invasion.

Immunohistochemical analysis of cancer-associated fibroblasts and podoplanin in head and neck cancer

Background

To immunohistochemically evaluate the association between the presence of cancer-associated fibroblasts (CAFs) and the tumour expression of podoplanin (PDPN) in head and neck squamous cell carcinoma (HNSCC) and their association with clinicopathological variables.

Material and Methods

A tissue microarray (TMA) with biopsy sections from patients diagnosed with HNSCC was stained with antibodies against the CAFs marker, α-smooth muscle actin (α-SMA), and PDPN. We subsequently evaluated their expression to determine the association between them and with clinicopathological variables including age, primary tumour site, TNM stage, and tumour differentiation grade.

Results

Positive reaction to α-SMA was observed in the tumour stroma, revealing spindle-shaped cells compatible with CAFs, which showed a high expression in 62% of cases and a significant association with laryngeal carcinomas, advanced clinical stages, and lower tumour differentiation (P ≤ 0.05). PDPN staining on tumour cells showed low expression in 72% of cases, and it was not associated with any clinicopathological variable or with the presence of CAFs.

Conclusions

The presence of CAFs in the tumour stroma is related to an aggressive phenotype and could increase as the disease progresses, although based on our findings, it would have no relationship, at least directly, with the expression of PDPN.

Key words:Cancer-associated fibroblasts, myofibroblasts, head and neck neoplasms, podoplanin, immunohistochemistry.

Tumour Microenvironment in Skin Carcinogenesis

Tumour microenvironment is a complex system comprising cells and molecules that will provide the necessary conditions for tumour development and progression. Cells residing in the tumour microenvironment gain specific phenotypes and specific functions that are pro-tumorigenic. Tumour progression is in fact a combination between tumour cell characteristics and its interplay with tumour microenvironment. This dynamic network will allow tumour cells to grow, migrate and invade tissues. In the present chapter, we are highlighting some traits that characterise tumour microenvironment in basal cell carcinoma, squamous cell carcinoma and cutaneous melanoma. In skin cancers, there are some common tumour microenvironment characteristics such as the presence of tumour-associated macrophages and regulatory T lymphocytes that are non-tumour cells promoting tumorigenesis. There are also skin cancer type differences in terms of tumour microenvironment characteristics. Thus, markers such as macrophage migration inhibitory factor in melanoma or the extraordinary diverse genetic make-up in the cancer-associated fibroblasts associated to squamous cell carcinoma are just a few of specific traits in skin cancer types. New technological advances for evaluation of tumour environment are presented. Thus, non-invasive skin imaging techniques such as reflectance confocal microscopy can evaluate skin tumour inflammatory infiltrates for density and cellular populations. Analysing tumour micromedium in depth may offer new insights into cancer therapy and identify new therapy targets.

Evaluation of SOX2 and podoplanin expression in oral epithelial dysplasia and its correlation with malignant transformation

AIM

Oral carcinogenesis cascade is a complex process, characterized by variable numbers of genetic and epigenetic alterations of various genes with manifold roles that could serve as biological hallmarks. This study was undertaken to assess the protein expression of SOX2 and podoplanin in oral epithelial dysplasia and correlate the expression with clinicopathological parameters and risk of malignant transformation.

METHODS

SOX2 and podoplanin expression were analyzed in 60 cases of oral epithelial dysplasia. The association between SOX2 and podoplanin expression with various clinicopathological parameters and transformation to oral cancer was analyzed.

RESULTS

A higher Histoscore was seen in 55% of moderate and 30% of severe dysplasia. 25% of the cases showed a negative podoplanin expression and 30% of patients had higher podoplanin expression (score 2 and 3). Though there was significant association of both SOX2 and podoplanin expression with the degree of dysplasia, the association of their expression with transformation to oral squamous cell carcinoma did not reach statistical significance.

CONCLUSION

Alteration in SOX2 and podoplanin is likely an important event in head and neck carcinogenesis; however, their expression may be valuable only in a few cases of oral epithelial dysplasia to assess the risk of malignant transformation.

Podoplanin in Inflammation and Cancer

Podoplanin is a small cell-surface mucin-like glycoprotein that plays a crucial role in the development of the alveoli, heart, and lymphatic vascular system. Emerging evidence indicates that it is also involved in the control of mammary stem-cell activity and biogenesis of platelets in the bone marrow, and exerts an important function in the immune response. Podoplanin expression is upregulated in different cell types, including fibroblasts, macrophages, T helper cells, and epithelial cells, during inflammation and cancer, where it plays important roles. Podoplanin is implicated in chronic inflammatory diseases, such as psoriasis, multiple sclerosis, and rheumatoid arthritis, promotes inflammation-driven and cancer-associated thrombosis, and stimulates cancer cell invasion and metastasis through a variety of strategies. To accomplish its biological functions, podoplanin must interact with other proteins located in the same cell or in neighbor cells. The binding of podoplanin to its ligands leads to modulation of signaling pathways that regulate proliferation, contractility, migration, epithelial⁻mesenchymal transition, and remodeling of the extracellular matrix. In this review, we describe the diverse roles of podoplanin in inflammation and cancer, depict the protein ligands of podoplanin identified so far, and discuss the mechanistic basis for the involvement of podoplanin in all these processes.

Cancer-associated fibroblasts contribute to oral cancer cells proliferation and metastasis via exosome-mediated paracrine miR-34a-5p

Background

Cancer-associated fibroblasts (CAFs) play an important role in regulating tumor progression by transferring exosomes to neighboring cells. Our aim was to clarify the role of microRNA encapsulated in the exosomes derived from CAFs in oral squamous cell carcinoma (OSCC).

Methods

We examined the microRNA expression profiles of exosomes derived from CAFs and donor-matched normal fibroblasts (NFs) from patients with OSCC. We used confocal microscopy to examine the transportation of exosomal miR-34a-5p between CAFs and OSCC cells. Next, luciferase reporter and its mutant plasmids were used to confirm direct target gene of miR-34a-5p. Phenotypic assays and in vivo tumor growth experiments were used to investigate the functional significance of exosomal miR-34a-5p.

Findings

We found that the expression of miR-34a-5p in CAF-derived exosomes was significantly reduced, and fibroblasts could transfer exosomal miR-34a-5p to OSCC cells. In xenograft experiments, miR-34a-5p overexpression in CAFs could inhibit the tumorigenesis of OSCC cells. We further revealed that miR-34a-5p binds to its direct downstream target AXL to suppress OSCC cell proliferation and metastasis. Stable ectopic expression of AXL in OSCC cells overexpressing miR-34a-5p restored proliferation and motility abolished by the miRNA. The miR-34a-5p/AXL axis promoted OSCC progression via the AKT/GSK-3β/β-catenin signaling pathway, which could induce the epithelial-mesenchymal transition (EMT) to promote cancer cells metastasis. The miR-34a-5p/AXL axis enhanced nuclear translocation of β-catenin and then induced transcriptional upregulation of SNAIL, which in turn activated both MMP-2 and MMP-9.

Interpretation

The miR-34a-5p/AXL axis confers aggressiveness in oral cancer cells through the AKT/GSK-3β/β-catenin/Snail signaling cascade and might represent a therapeutic target for OSCC.

Fund

National Natural Science Foundation of China.

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CAFs transfer miR-34a-5p-devoid exosomes to OSCC cells.

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Exosomal miR-34a-5p mediates the proliferation and motility of OSCC cells through regulating AXL.

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MiR-34a-5p/AXL axis confers aggressiveness in OSCC through AKT/GSK-3β/β-catenin/Snail signaling cascade.