Central malignant salivary gland tumor of the mandible is rarely observed with adenoid cystic carcinoma, which only comprises a small proportion of cancer patients. In this study, a patient with central adenoid cystic carcinoma of the mandible is presented, and relevant literature is reviewed.
Carcinoma, Adenoid Cystic ; diagnosis ; Humans ; Mandible ; pathology ; Salivary Gland Neoplasms ; diagnosis

Osgood-Schlatter disease (OSD) is a common strain disease in adolescents, which is more common in youth sports enthusiasts, athletes and soldiers. The clinical manifestations of OSD are typical, and the diagnosis can be made based on the medical history, physical examination and knee X-ray examination, but it needs to be differentiated from other diseases that may cause anterior knee pain. The risk factors of OSD development include males, 12-15 years of age in males and 8-12 years of age in females, high body mass index, skeletal-muscular anatomical variants, and large amount of exercise, etc. OSD is a self-limited disorder that gradually resolves as the skeleton maturates. Most patients do not need treatment or can also be treated with conservative methods such as exercise therapy, medications and physical therapy, but may be left with sequelae that affect motor function and quality of life. Clinical attention should be paid to it adequately. If the conservative treatment is ineffective, active operation should be performed. The principle of operation is to remove bone fragments and reconstruct tibial tuberosity. Common surgical procedures include traditional open surgery and arthroscopic surgery. Arthroscopic surgery, with its advantages of minimally invasive and rapid recovery, is currently advocated as the best surgical procedure, but the mid- and long-term efficacy is unclear.

As an important component of the tumor microenvironment, cancer-associated fibroblasts (CAFs) secrete energy metabolites to supply energy for tumor progression. Abnormal regulation of long noncoding RNAs (lncRNAs) is thought to contribute to glucose metabolism, but the role of lncRNAs in glycolysis in oral CAFs has not been systematically examined. In the present study, by using RNA sequencing and bioinformatics analysis, we analyzed the lncRNA/mRNA profiles of normal fibroblasts (NFs) derived from normal tissues and CAFs derived from patients with oral squamous cell carcinoma (OSCC). LncRNA H19 was identified as a key lncRNA in oral CAFs and was synchronously upregulated in both oral cancer cell lines and CAFs. Using small interfering RNA (siRNA) strategies, we determined that lncRNA H19 knockdown affected proliferation, migration, and glycolysis in oral CAFs. We found that knockdown of lncRNA H19 by siRNA suppressed the MAPK signaling pathway, 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3) and miR-675-5p. Furthermore, the lncRNA H19/miR-675-5p/PFKFB3 axis was involved in promoting the glycolysis pathway in oral CAFs, as demonstrated by a luciferase reporter system assay and treatment with a miRNA-specific inhibitor. Our study presents a new way to understand glucose metabolism in oral CAFs, theoretically providing a novel biomarker for OSCC molecular diagnosis and a new target for antitumor therapy.
Cancer-Associated Fibroblasts/metabolism* ; Carcinoma, Squamous Cell/genetics* ; Cell Line, Tumor ; Cell Proliferation ; Gene Expression Regulation, Neoplastic ; Glycolysis ; Head and Neck Neoplasms ; Humans ; MicroRNAs/metabolism* ; Mouth Neoplasms/genetics* ; Phosphofructokinase-2/genetics* ; RNA, Long Noncoding/genetics* ; Signal Transduction ; Tumor Microenvironment

Oral squamous cell carcinoma (OSCC) escape from the immune system is mediated through several immunosuppressive phenotypes that are critical to the initiation and progression of tumors. As a hallmark of cancer, DNA damage repair is closely related to changes in the immunophenotypes of tumor cells. Although flap endonuclease-1 (FEN1), a pivotal DNA-related enzyme is involved in DNA base excision repair to maintain the stability of the cell genome, the correlation between FEN1 and tumor immunity has been unexplored. In the current study, by analyzing the clinicopathological characteristics of FEN1, we demonstrated that FEN1 overexpressed and that an inhibitory immune microenvironment was established in OSCC. In addition, we found that downregulating FEN1 inhibited the growth of OSCC tumors. In vitro studies provided evidence that FEN1 knockdown inhibited the biological behaviors of OSCC and caused DNA damage. Performing multiplex immunohistochemistry (mIHC), we directly observed that the acquisition of critical immunosuppressive phenotypes was correlated with the expression of FEN1. More importantly, FEN1 directly or indirectly regulated two typical immunosuppressive phenotype-related proteins human leukocyte antigen (HLA-DR) and programmed death receptor ligand 1 (PD-L1), through the interferon-gamma (IFN-γ)/janus kinase (JAK)/signal transducer and activator transcription 1 (STAT1) pathway. Our study highlights a new perspective on FEN1 action for the first time, providing theoretical evidence that it may be a potential immunotherapy target for OSCC.
Humans ; Carcinoma, Squamous Cell/pathology* ; DNA ; Down-Regulation ; Flap Endonucleases/metabolism* ; Head and Neck Neoplasms ; Interferon-gamma/metabolism* ; Mouth Neoplasms/pathology* ; Phenotype ; Squamous Cell Carcinoma of Head and Neck ; Tumor Microenvironment ; Janus Kinases/metabolism*