Sixteen Cellular Senescence-associated DNA Methylation Signature Predicts Overall Survival in Patients with Head and Neck Squamous Cell Carcinoma.

OBJECTIVE: To construct a cellular senescence-related DNA methylation model to act as an independent prognosis predictor for patients with head and neck squamous cell carcinoma (HNSCC). METHODS: Methylome, transcriptome and clinical information for 499 HNSCC patients were received from The Cancer Genome Atlas (TCGA) as a training set. An extra independent methylation dataset of 54 patients with oral squamous cell carcinoma (OSCC) was downloaded from the NCBI Gene Expression Omnibus (GEO) database as the validation set. To assess the cellular senescence level of each sample, the senescence score (SS) of each patient was calculated using the transcriptome data via single-sample gene set enrichment analysis (ssGSEA). Least absolute shrinkage and selection operator (LASSO) Cox regression analyses were conducted to confirm Cytosine, phosphoric acid and Guanine (CpG) sites for the development of a cellular senescence-related DNA methylation signature. RESULTS: Based on the SS of each HNSCC patient in the TCGA cohort, the patients were divided into high- and low-SS subgroups. The high-SS group showed a better prognosis than the low-SS group. Moreover, 3,261 differentially methylated CpG sites (DMCs) were confirmed between the two groups. Among them, 16 DMCs were included to develop a 16-DNA methylation signature for evaluation of HNSCC prognosis using LASSO and multivariate Cox regression analysis. CONCLUSION: A novel cellular senescence-related 16-DNA methylation signature was determined, which can be used as an independent index to evaluate the prognosis of HNSCC patients and select appropriate treatment strategies.

Gasless Endoscopic Submandibular Gland Excision Through Hairline Approach.

BACKGROUND: The aim of this study was to evaluate the therapeutic effect of gasless endoscopic submandibular gland excision through hairline approach and the safety, feasibility and practicability of this technique. METHODS: Twenty-five patients with submandibular gland lesions who underwent gasless endoscopic submandibular gland excision through hairline approach at the Department of Head and Neck Oncology of the West China Hospital of Stomatology from May 1 st 2021 to May 31 st 2022 were included in this prospective study. The variables were analyzed statistically with SPSS software version 23.0 (IBM Corp, Armonk, New York, USA). RESULTS: There was a female predominance (72%), female to male ratio was 2.6. The mean age was 30.6±10.2 years (range: 11 to 52 year). All 25 cases of endoscopic submandibular gland excision through hairline approach were done without conversion to conventional approach. This approach was indicated in 14 cases (56%) for pleomorphic adenoma, 8 cases (32%) for chronic sialadenitis, 2 cases (8%) for adenoid cystic carcinoma, and 1 case (4%) for lymphadenitis. The incision length mean was 4.8±0.4 mm (range: 4 to 5 mm); the operation duration mean was 100.6±39.7 min (range: 51 to 197 min); the intraoperative bleeding mean was 13.2±5.7 ml (range: 5 to 20 ml); the hospital length of stay mean was 4.5±0.8 days (range: 3 to 6 days). The follow-up mean was 10±3.4 months (range: 5 to 16 months). The patients were very satisfied with postoperative cosmetic result (score mean: 9.2±1). No recurrence of disease and complications such as postoperative bleeding, hematoma, nerve damage, skin necrosis, infection, and hair loss occurred. CONCLUSIONS: Gasless endoscopic submandibular gland excision through hairline approach is safe, feasible and practicable, resulting in a very satisfied cosmetic result without significant complications; the intraoperative bleeding is less, the operative field is clear, the operation duration decreases with accumulation of experience.

Single incision-plus approach for gasless endoscopic parotidectomy: a seven-step procedure.

Endoscopic parotidectomy has the potential to become a reliable procedure for benign and low-grade malignant parotid gland tumors. Based on the previous literature review and our own clinical experience, we introduced in detail the surgical procedure of single incision-plus approach for gasless endoscopic parotidectomy. This method contributes a logical approach to achieving endoscopic resection of parotid gland tumor and preservation of facial nerve, which can be summarized into the following seven-step method: preoperative preparation; design of retroauricular-hairline incision and plus-incision; surgical cavities creation and coalescence; separation of surgical boundaries; separation and protection of the facial nerve trunk; processing of the branches of facial nerve; en bloc resection of the superficial parotid gland and tumor. Endoscopic parotidectomy is a more difficult procedure than conventional parotid surgery, requiring more precision as well as more experience and equipment. The learning curve of time and frequency is influenced by many factors, like anatomy, instruments, procedures and patience. We contribute our clinical exploration of anatomical precautions, feasible instruments, and surgical procedures and summarize precautions under single incision-plus in gasless endoscopic parotidectomy. Given the growing interest in the aesthetic process of the parotid region, the seven-step method may have the potential to be a method for teaching gasless endoscopic parotidectomy.

Preoperative high-frequency color Doppler ultrasound assessment of the blood vessels of the fibular myocutaneous flap.

OBJECTIVE: The fibular myocutaneous flap is a classic flap used to reconstruct oral and maxillofacial defects. This study aimed to evaluate the effectiveness of high-frequency color Doppler ultrasound in detecting the blood vessels in the fibular myocutaneous flap, analyze the influence of variations in the peroneal vessels and perforating peroneal arteries on the surgical design, and explore the value of this technology in preoperatively assessing the blood vessels of the fibular myocutaneous flap. METHODS: Twenty-five patients with mandibular disease or defect underwent preoperative evaluation of the blood vessels of the calf by high-frequency color Doppler ultrasound. The inner diameter and peak systolic velocity (PSV) of the peroneal arteries and veins and the perforating peroneal arteries were compared between different groups. The consistency between the perforating peroneal arteries marked by ultrasonography and the intraoperative findings was analyzed. RESULTS: The initial segment of the peroneal artery had a larger inner diameter (p<0.001) and lower PSV (p<0.05) than the middle segment. The perforating peroneal arteries were mainly distributed in the middle of the fibula. The inner diameter of the perforating peroneal artery was larger in men than in women (p<0.05). In comparison with surgical exploration as the gold standard, high-frequency color Doppler ultrasound results showed good consistency (Kappa=0.684, 95% CI: 0.512-0.856, p<0.001), with a sensitivity of 89.36%, specificity of 78.57%, and accuracy of 85.33%. CONCLUSION: High-frequency color Doppler ultrasound can detect, quantitatively evaluate, and accurately mark the peroneal artery and vein and perforating peroneal artery before fibular myocutaneous flap transplantation.

Interactions Among Non-Coding RNAs and mRNAs in the Trigeminal Ganglion Associated with Neuropathic Pain.

Background: Recent studies have demonstrated the contribution of non-coding RNAs (ncRNAs) to neuropathic pain. However, the expression profile of ncRNAs in the trigeminal ganglion (TG) and their functional mechanism underlying trigeminal neuropathic pain are still unclear. Methods: In the present study, the trigeminal neuropathic pain model induced by chronic constriction injury of the infraorbital nerve (CCI-ION) was used to study the expression profile and potential regulatory mechanism of miRNAs, lncRNAs, circRNAs, and mRNAs in the TG by RNA-sequencing (RNA-seq) and bioinformatics analysis. CCI-ION mice suffered from mechanical allodynia from 3 days to 28 days after surgery. Results: The RNA-seq results discovered 67 miRNAs, 216 lncRNAs, 14 circRNAs, 595 mRNAs, and 421 genes were differentially expressed (DE) in the TG of CCI-ION mice 7 days after surgery. And 39 DEGs were known pain genes. Besides, 5 and 35 pain-related DE mRNAs could be targeted by 6 DE miRNAs and 107 DE lncRNAs, respectively. And 23 pain-related DEGs had protein-protein interactions (PPI) with each other. GO analysis indicated membrane-related cell components and binding-related molecular functions were significantly enriched. KEGG analysis showed that nociception-related signaling pathways were significantly enriched for DE ncRNAs and DEGs. Finally, the competing endogenous RNA (ceRNA) regulatory network of DE lncRNA/DE circRNA-DE miRNA-DE mRNA existed in the TG of mice with trigeminal neuropathic pain. Conclusion: Our findings demonstrate ncRNAs are involved in the development of trigeminal neuropathic pain, possibly through the ceRNA mechanism, which brings a new bright into the study of trigeminal neuropathic pain and the development of novel treatments targeting ncRNAs.

Activation of the N-methyl-D-aspartate receptor contributes to orofacial neuropathic and inflammatory allodynia by facilitating calcium-calmodulin-dependent protein kinase II phosphorylation in mice.

Neuropathic and inflammatory pain are major clinical challenges due to their ambiguous mechanisms and limited treatment approaches. N-methyl-D-aspartate receptor (NMDAR) and calcium-calmodulin-dependent protein kinase II (CaMKII) are responsible for nerve system sensation and are required for the induction and maintenance of pain. However, the roles of NMDAR and CaMKII in regulating orofacial pain are still less well known. Here, we established a neuropathic pain model by transecting a mouse inferior alveolar nerve (IAN) and an inflammatory pain model by injecting complete Freund's adjuvant (CFA) into its whisker pad. The Cre/loxp site-specific recombination system was used to conditionally knock out (KO) NR2B in the trigeminal ganglion (TG). Von Frey filament behavioral tests showed that IANX and CFA-induced mechanical allodynia were altered in NR2B-deficient mice. CFA upregulated CaMKIIα and CaMKIIß in the mouse TG and spinal trigeminal caudate nucleus (SpVc). CaMKIIα first decreased and then increased in the TG after IANX, and CaMKIIß decreased in the TG and SpVc. CFA and IANX both greatly enhanced the expression of phospho (p)-NR2B, p-CaMKII, cyclic adenosine monophosphate (cAMP), p-ERK, and p-cAMP response element binding protein (CREB) in the TG and SpVc. These neurochemical signal pathway alterations were reversed by the conditional KO of NR2B and inhibition of CaMKII. Similarly, IANX- and CFA-related behavioral alterations were reversed by intra-ganglionic (i.g.) -application of inhibitors of CaMKII, cAMP, and ERK. These findings revealed novel molecular signaling pathways (NR2B-CaMKII-cAMP-ERK-CREB) in the TG- and SpVc-derived latent subsequent peripheral and spinal central sensitization under nerve injury and inflammation, which might be beneficial for the treatment of orofacial allodynia.

C-X-C motif chemokine ligand 1 and its receptor C-X-C motif chemokine receptor 2 in trigeminal ganglion contribute to nerve injury-induced orofacial mechanical allodynia.

BACKGROUND: Orofacial ectopic pain induced by trigeminal nerve injury is a serious complication of dental treatment. C-X-C motif chemokine ligand 1 (CXCL1) and its primary receptor C-X-C motif chemokine receptor 2 (CXCR2) contribute to the development and maintenance of neuropathic pain in the spinal nervous system, but their roles in trigeminal neuropathic sensation are still poorly understood. OBJECTIVES: This study aimed to investigate the exact role of CXCL1 and CXCR2 in the regulation of orofacial ectopic mechanical allodynia and their potential downstream mechanisms in the trigeminal ganglion (TG). METHODS: The head withdrawal threshold (HWT) of C57BL/6 mice was evaluated after inferior alveolar nerve (IAN) transection (IANX). Then, the distribution and expression of CXCL1 and CXCR2, and their potential downstream mechanisms in the TG were further measured using immunohistochemistry, real-time reverse transcription-quantitative polymerase chain reaction and Western blotting. Moreover, the effect of SB225002 (an inhibitor of CXCR2) on mechanical allodynia was examined. The data were analysed using the Student's t test and a analysis of variance (ANOVA). RESULTS: IANX triggered persistent (>21 days) mechanical allodynia and upregulation of CXCL1 and CXCR2 in the TG. In addition, exogenous CXCL1 also lowered the HWT, which was alleviated by CXCR2 and protein kinase C (PKC) antagonists (p < .05). In addition, IANX increased the phosphorylated PKC (p-PKC) levels and decreased the expression of voltage-gated potassium channels (Kv), and these effects were reversed by inhibition of CXCR2 (p < .05). CONCLUSION: Our results demonstrated that CXCR2 participated in orofacial ectopic mechanical allodynia via downregulation of Kv1.4 and Kv1.1 through the PKC signalling pathway. This mechanism may be a potential target in developing a treatment strategy for ectopic orofacial pain.

Peripheral odontogenic keratocysts in buccal soft tissues: two cases report.

Peripheral odontogenic keratocysts are rarely observed, and cases of odontogenic keratocysts of buccal soft tissues are even rarer. This study was performed to present two rare cases of odontogenic keratocysts in buccal soft tissues and review related literature.

Effect of piceatannol against malignant melanoma in vivo and in vitro.

OBJECTIVES: To study the antitumor effect of piceatannol (PIC) on malignant melanoma in vitro and in vivo. METHODS: B16F10 cells were cultured in vitro and treated with gradient concentrations of PIC. Cell viability was detected with methyl thiazolyl tetrazolium (MTT) assay; matrix metalloproteinase (MMP)-2, MMP-9, vascular endothelial growth factor (VEGF), spleen tyrosine kinase (Syk), and p-Syk were detected with Western blot; migration ability was detected with wound healing assay; invasion ability was detected with Transwell assay. Syk expression was suppressed through RNA interference for the detection of the possible mechanism of PIC in melanoma. An in vivo study was established by creating B16F10-bearing mice with intraperitoneal injection of PIC. RESULTS: The cell viability of B16F10 decreased with increasing PIC concentration. The results of the Transwell assay showed that invasion ability decreased with increasing PIC concentration, and healing time was prolonged at increased PIC concentration in the wound healing assay. Western blot results showed that PIC mainly inhibited the phosphorylation of Syk and inhibited the expression of MMP-2, MMP-9, and VEGF. RNA interference pointed out that blocking the expression of Syk can reveal the same inhibition effect on B16F10 cells as PIC. In vivo study revealed that different concentrations of PIC cangreatly inhibit melanoma progression. CONCLUSIONS: PIC might block the progression of malignant melanoma by inhibiting spleen tyrosine kinase.

[Advances in molecular mechanisms of bone invasion by oral cancer].

Bone invasion by oral cancer is a common clinical problem, which affects the choice of treatment and predicts a poor prognosis. Unfortunately, the molecular mechanism of this phenomenon has not been fully elucidated. Current studies have revealed that oral cancer cells modulate the formation and function of osteoclasts through the expression of a series of signal molecules. Many signal pathways are involved in this process, of which receptor activator of nuclear factor-κB ligand/receptor activator of nuclear factor-κB/osteoprotegerin signaling pathway attracted much attention. In this review, we introduce recent progress in molecular mechanisms of bone invasion by oral cancer.

Advances on mechanism and treatment of salivary gland in radiation injury.

Oral squamous cell carcinoma (OSCC) is the most frequent tumour in head and neck malignant. The current treatment is mainly based on surgery therapy, radiation therapy and chemical therapy. Meanwhile, there are many a defect in the treatment. For example, there are many defects in radiotherapy. Radioactive salivatitis is the most common. In addition, there are a series of changes such as dry mouth, oral mucositis, rampant dental caries, and radioactive osteomyelitis of jaw, which cause swallowing, chewing problems, and taste dysfunction. Currently, the research on radioactive salivatitis is progressing rapidly, but its mechanism is more complication. This paper review aims to summarize the research progress in this field.

Activation of oxytocin receptor in the trigeminal ganglion attenuates orofacial ectopic pain attributed to inferior alveolar nerve injury.

This study explores the effects of oxytocin receptor (OXTR) in the trigeminal ganglion (TG) on orofacial neuropathic pain. We demonstrate that OXTR activation in the TG relieves the orofacial ectopic pain as well as inhibits the upregulated expression of calcitonin gene-related peptide (CGRP), IL-1ß, and TNFα in the TG and spinal trigeminal nucleus caudalis (SpVc) of rats with inferior alveolar nerve transection. OXTR, a G protein-coupled receptor, has been demonstrated to play a significant role in analgesia after activation by its canonical agonist oxytocin (OXT) in the dorsal root ganglion. However, the role of OXTR in the trigeminal nervous system on the orofacial neuropathic pain is still little known. In the present study, we aimed to investigate the regulation effect and mechanism of OXTR in the TG) and SpVc) on orofacial ectopic pain induced by trigeminal nerve injury. The inferior alveolar nerve (IAN) was transected to establish a ectopic pain model. A behavioral test with electronic von Frey filament demonstrated IAN transection (IANX) evoked mechanical hypersensitivity in the whisker pad from day 1 to at least day 14 after surgery. In addition, administration of OXT (50 and 100 µM) into the TG attenuated the mechanical hypersensitivity induced by IANX, which was reversed by pretreatment with L-368,899 (a selective antagonist of OXTR) into the TG. In addition, immunofluorescence showed the expression of OXTR in neurons in the TG and SpVc. Furthermore, Western blot analysis indicated that the upregulated expression of OXTR, CGRP, IL-1ß, and TNFα in the TG and SpVc after IANX was inhibited by the administration of OXT into the TG. And the inhibition effect of OXT on the expression of CGRP, IL-1ß, and TNFα was abolished by preapplication of OXTR antagonist L-368,899 into the TG.NEW & NOTEWORTHY This study explores the effects of oxytocin receptor (OXTR) in the trigeminal ganglion (TG) on orofacial neuropathic pain. We demonstrate that OXTR activation in the TG relieves the orofacial ectopic pain as well as inhibits the upregulated expression of calcitonin gene-related peptide, IL-1ß, and TNF-α in the TG and spinal trigeminal nucleus caudalis of rats with inferior alveolar nerve transection.

Nerve growth factor protects salivary glands from irradiation-induced damage.

AIMS: Radiotherapy has become a basic treatment modality for head and neck cancer. However, radiotherapy results in inevitable side effects, particularly radiation sialadenitis, that significantly impairs quality of life. A previous study indicated that nerve growth factor (NGF) has a radio-protective effect, but the mechanism was not determined in salivary glands. In this study, we explored the functional role and mechanism regarding how NGF protects salivary glands against IR-induced damage. MAIN METHODS: Human salivary gland (HSG) cells and C57BL/6 mice were selected to establish an IR-induced salivary gland damage model in vitro and in vivo. Recombinant NGF protein and NGF siRNA and over-expression plasmids were applied to manipulate NGF expression in vitro. AAV-NGF was retrogradely perfused into the submandibular gland (SMG) through the SMG duct to manipulate NGF expression in vitro. Small-molecule inhibitors and siRNAs were applied to inhibit AKT and JNK. Western blotting, quantitative PCR, flow cytometry and histology assays were performed to analyse the functional role and mechanism of NGF. KEY FINDINGS: Our study demonstrated that NGF expression was upregulated following radiotherapy both in human HSG cells and mouse SMG tissues. NGF could reduce IR-induced HSG cell apoptosis, and AAV-mediated gene therapy could restore the salivary flow rate and protect the salivary gland against IR-induced apoptosis in vivo. Mechanistically, NGF protects salivary glands from IR-induced apoptosis by de-phosphorylating JNK kinase rather than promoting AKT phosphorylation. SIGNIFICANCE: The current study findings indicated that the modulation of the NGF pathway might prevent IR-induced salivary hypo-function.

[Application of mixed reality in oromaxillofacial head and neck oncology surgery: a preliminary study].

Mixed reality (MR), characterized by the ability to integrate digital data into human real feeling, is a new technique in medical imaging and surgical navigation. MR has tremendous value in surgery, but its application in oromaxillofacial head and neck oncology surgery is not yet reported. This paper reports the application of MR in oromaxillofacial head and neck oncology surgery. The merits, demerits, and present research situations and prospects of MR are further discussed.

Rapid diagnosis of IDH1-mutated gliomas by 2-HG detection with gas chromatography mass spectrometry.

The metabolic genes encoding isocitrate dehydrogenase (IDH1, 2) are frequently mutated in gliomas. Mutation of IDH defines a distinct subtype of glioma and predicts therapeutic response. IDH mutation has a remarkable neomorphic activity of converting α-ketoglutarate (α-KG) to 2-hydroxyglutarate (2-HG), which is now commonly referred to as an oncometabolite and biomarker for gliomas. PCR-sequencing (n = 220), immunohistochemistry staining (IHC, n = 220), and gas chromatography mass spectrometry (GC-MS, n = 87) were applied to identify IDH mutation in gliomas, and the sensitivity and specificity of these strategies were compared. PCR-sequencing and IHC staining are reliable for retrospective assessment of IDH1 mutation in gliomas, but both methods usually take 1-2 days, which hinders their application for rapid diagnosis. GC-MS-based methods can detect 2-HG qualitatively and quantitatively, offering information on the IDH1 mutation status in gliomas with the sensitivity and specificity being 100%. Further optimization of the GC-MS based methodology (so called as the mini-column method) enabled us to determine 2-HG within 40 min in glioma samples without complex or time-consuming preparation. Most importantly, the ratio of 2-HG/glutamic acid was shown to be a reliable parameter for determination of mutation status. The mini-column method enables rapid identification of 2-HG, providing a promising strategy for intraoperative diagnosis of IDH1-mutated gliomas in the future.

[Clavicle fracture after radical neck dissection of mouth floor carcinoma misdiagnosed as cervical metastasis: a case report].

Clavicle fracture, a very rare delayed complication following radical neck dissection of oral carcinoma, is normally ignored by oral and maxillofacial surgeons. We report and analyze a male patient with clavicle fracture after primary extended excision and bilateral radical neck dissection. This case was misdiagnosed as cervical metastasis.

[Contrast-enhanced CT for the diagnosis of extracapsular spread by head and neck cancers: a systematic review and meta analysis].

PURPOSE: This study aimed to assess the diagnostic efficacy of contrast-enhanced CT in the screening of extracapsular spread by head and neck cancers. METHODS: Electronic databases, including MEDLINE, EMBASE,CBM,CNKI and SciencePaper Online were searched electronically. Hand-searching was also performed. QUADAS-2 was used by two independent reviewers to assess the methodological quality, and data extraction of included studies was delivered. Meta analysis was conducted via MetaDisc1.4 and STATA 11.0. RESULTS: A total of 8 studies involving 639 participants were included. All studies were retrospective, 1 had high risk of bias, and the remaining had unclear risk of bias. Meta analysis showed that when screening extracapsular spread, contrast-enhanced CT had a pooled sensitivity of 0.67, pooled specificity of 0.84, area under curve of 0.83. CONCLUSIONS: Contrast-enhanced CT is a good tool for diagnosing extracapsular spread by head and neck cancers.

The proto-oncogene tyrosine protein kinase Src is essential for macrophage-myofibroblast transition during renal scarring.

Src activation has been associated with fibrogenesis after kidney injury. Macrophage-myofibroblast transition is a newly identified process to generate collagen-producing myofibroblasts locally in the kidney undergoing fibrosis in a TGF-ß/Smad3-dependent manner. The potential role of the macrophage-myofibroblast transition in Src-mediated renal fibrosis is unknown. In studying this by RNA sequencing at single-cell resolution, we uncovered a unique Src-centric regulatory gene network as a key underlying mechanism of macrophage-myofibroblast transition. A total of 501 differentially expressed genes associated with macrophage-myofibroblast transition were identified. However, Smad3-knockout largely reduced the transcriptome diversity. More importantly, inhibition of Src largely suppresses ureteral obstruction-induced macrophage-myofibroblast transition in the injured kidney in vivo along with transforming growth factor-ß1-induced elongated fibroblast-like morphology, α-smooth muscle actin expression and collagen production in bone marrow derived macrophages in vitro. Unexpectedly, we further uncovered that Src serves as a direct Smad3 target gene and also specifically up-regulated in macrophages during macrophage-myofibroblast transition. Thus, macrophage-myofibroblast transition contributes to Src-mediated tissue fibrosis. Hence, targeting Src may represent as a precision therapeutic strategy for macrophage-myofibroblast transition-driven fibrotic diseases.

[Investigation of the effect of nuclear factor κB on inflammatory cell recruitment phenotype of oral cancer associated macrophage].

PURPOSE: To explore the ability of nuclear factor κB (NFκB) in sustaining inflammatory cell recruitment phenotype of oral cancer associated macrophages, by using NFκB inhibitor(-Bay11-7082). METHODS: By primary culture, murine macrophages were harvested. Cal27 conditioned medium (CM) and Bay11-7082 were applied for stimulation of the macrophages. RT-PCR and ELISA were used for detecting the inflammatory cell recruitment related chemotactic factors. GraphPadPrism5 was used for statistical analysis. RESULTS: Bay11-7082 prevented the contour change into a spindle shape via Cal 27 CM. It also attenuated MCP-1, GM-CSF, MCP-5 and CCL-5 mRNA increase after Cal 27 CM stimulation (P<0.05). At protein level, impeding NFκB activation could significantly prevent MCP-1 and GM-CSF secretion from oral cancer associated macrophage (P<0.001). CONCLUSIONS: NFκB signaling may play a key role in sustaining the inflammatory cell recruitment phenotype of oral cancer associated macrophages.

Smad3 promotes cancer progression by inhibiting E4BP4-mediated NK cell development.

TGF-ß is known to influence tumour progression. Here we report an additional role of Smad3 in the tumour microenvironment regulating cancer progression. Deletion or inhibition of Smad3 in the tumour microenvironment suppresses tumour growth, invasion and metastasis in two syngeneic mouse tumour models. Smad3-/- bone marrow gives rise to an expanded NK cell population with enhanced tumour-suppressive activities in vivo, and promotes differentiation of NK cells ex vivo. We identify E4BP4/NFIL3 as a direct Smad3 target gene critical for NK cell differentiation. Smad3 suppresses transcription of IFN-γ via E4BP4 in a T-bet independent manner. Therefore disruption of Smad3 enhances both the E4BP4-mediated NK cell differentiation and anti-cancer effector functions in vivo and in vitro. Furthermore, systemic treatment with a Smad3 inhibitor SIS3 effectively suppresses cancer progression. In summary, suppression of NK cell-mediated immunosurveillance via the Smad3-E4BP4 axis contributes to cancer progression. We propose targeting Smad3-dependent tumour microenvironment may represent an effective anti-cancer strategy.