Genomic alterations in oral multiple primary cancers

Oral squamous cell carcinoma (OSCC) is the predominant type of oral cancer, while some patients may develop oral multiple primary cancers (MPCs) with unclear etiology. This study aimed to investigate the clinicopathological characteristics and genomic alterations of oral MPCs. Clinicopathological data from patients with oral single primary carcinoma (SPC, n=202) and oral MPCs (n=34) were collected and compared. Copy number alteration (CNA) analysis was conducted to identify chromosomal-instability differences among oral MPCs, recurrent OSCC cases, and OSCC patients with lymph node metastasis. Whole-exome sequencing was employed to identify potential unique gene mutations in oral MPCs patients. Additionally, CNA and phylogenetic tree analyses were used to gain preliminary insights into the molecular characteristics of different primary tumors within individual patients. Our findings revealed that, in contrast to oral SPC, females predominated the oral MPCs (70.59%), while smoking and alcohol use were not frequent in MPCs.Moreover, long-term survival outcomes were poorer in oral MPCs. From a CNA perspective, no significant differences were observed between oral MPCs patients and those with recurrence and lymph node metastasis. In addition to commonly mutated genes such as CASP8, TP53 and MUC16, in oral MPCs we also detected relatively rare mutations, such as HS3ST6 and RFPL4A. Furthermore, this study also demonstrated that most MPCs patients exhibited similarities in certain genomic regions within individuals, and distinct differences of the similarity degree were observed between synchronous and metachronous oral MPCs.

Mapping the immune microenvironment for mandibular alveolar bone homeostasis at single-cell resolution

Alveolar bone is the thickened ridge of jaw bone that supports teeth.It is subject to constant occlusal force and pathogens invasion,and is therefore under active bone remodeling and immunomodulation.Alveolar bone holds a distinct niche from long bone considering their different developmental origin and postnatal remodeling pattern.However,a systematic explanation of alveolar bone at single-cell level is still lacking.Here,we construct a single-cell atlas of mouse mandibular alveolar bone through single-cell RNA sequencing(scRNA-seq).A more active immune microenvironment is identified in alveolar bone,with a higher proportion of mature immune cells than in long bone.Among all immune cell populations,the monocyte/macrophage subpopulation most actively interacts with mesenchymal stem cells(MSCs)subpopulation.Alveolar bone monocytes/macrophages express a higher level of Oncostatin M(Osm)compared to long bone,which promotes osteogenic differentiation and inhibits adipogenic differentiation of MSCs.In summary,our study reveals a unique immune microenvironment of alveolar bone,which may provide a more precise immune-modulatory target for therapeutic treatment of oral diseases.

Insights into skeletal stem cells

The tissue-resident skeletal stem cells(SSCs),which are self-renewal and multipotent,continuously provide cells(including chondrocytes,bone cells,marrow adipocytes,and stromal cells)for the development and homeostasis of the skeletal system.In recent decade,utilizing fluorescence-activated cell sorting,lineage tracing,and single-cell sequencing,studies have identified various types of SSCs,plotted the lineage commitment trajectory,and partially revealed their properties under physiological and pathological conditions.In this review,we retrospect to SSCs identification and functional studies.We discuss the principles and approaches to identify bona fide SSCs,highlighting pioneering findings that plot the lineage atlas of SSCs.The roles of SSCs and progenitors in long bone,craniofacial tissues,and periosteum are systematically discussed.We further focus on disputes and challenges in SSC research.

Management of extramedullary plasmacytoma: Role of radiotherapy and prognostic factor analysis in 55 patients

Objective： To investigate potential prognostic factors affecting patient outcomes and to evaluate the optimal methods and effects of radiotherapy（RT） in the management of extramedullary plasmacytoma（EMP）.Methods： Data from 55 patients with EMP between November 1999 and August 2015 were collected. The median age was 51（range, 22–77） years. The median tumor size was 3.5（range, 1.0–15.0） cm. The median applied dose was 50.0（range, 30.0–70.0） Gy. Thirty-nine patients（70.9%） presented with disease in the head or neck region. Twelve patients received RT alone, 9 received surgery（S） alone, 3 received chemotherapy（CT） alone, and 3 patients did not receive any treatment. Combination therapies were applied in 28 patients.Results：The median follow-up duration was 56 months.The 5-year local recurrence-free survival（LRFS）,multiple myeloma-free survival（MMFS）,progression-free survival（PFS）and overall survival（OS）rates were 79.8%,78.6%,65.2% and 76.0%,respectively.Univariate analysis revealed that RT was a favourable factor for all examined endpoints.Furthermore,head and neck EMPs were associated with superior LRFS,MMFS and PFS.Tumor size〈4 cm was associated with superior MMFS,PFS and OS;serum M protein negativity was associated with superior MMFS and PFS;age≥50 years and local recurrence were associated with poor MMFS.The dose≥45 Gy group exhibited superior 5-year LRFS,MMFS and PFS rates（94.7%,94.4%,90.0%,respectively）,while the corresponding values for the dose〈45 Gy group were 62.5%（P=0.008）,53.3%（P=0.036）and 41.7%（P〈0.001）.Conclusions：Involved-site RT of at least 45 Gy should be considered for EMP.Furthermore,patients with head and neck EMP,tumor size〈4 cm,age〈50 years and serum M protein negativity had better outcomes.

The design,mechanism and biomedical application of self-healing hydrogels

Hydrogels are promising materials with outstanding characteristics such as tunable and reversible physical/chemical properties,stimuli-responsiveness,biomimetic,and biocompatibility.However,the structural and functional integrity of the hydrogels can be compromised by external mechanical forces or chemical erosion when used,especially in sophisticated in vivo environment.To address this problem,self-healing hydrogels which possess the intrinsic ability of self-repair have been developed to adapt to destructive factors.In this review,we focused on the current advances made in self-healing hydrogels.First,the testing methods for self-healing hydrogels were summarized.Then,we looked into the designing strategies of self-healing hydrogels and illustrated the self-healing mechanism.What＇s more,the biomedical application of self-healing hydrogels in vivo was discussed.

METTL5 regulates cranial suture fusion via Wnt signaling

METTL5 is a methyltransferase that mediates eukaryotic 18S ribosomal RNA m^(6)A modification,and its mutations lead to intellectual disability,microcephaly,and facial dysmorphism in patients.However,the role of METTL5 in craniofacial development remains poorly understood.This study demonstrates that Mettl5 knockout mice exhibit poor ossification,widened cranial sutures,and a cleidocranial dysplasia-like phenotype.Deletion of Mettl5 leads to increased proliferation and decreased osteogenic differentiation of suture mesenchymal stem cells.Mechanistically,we find that Wnt signaling is significantly downregulated after Mettl5 knockout.Overall,we reveal an essential role of METTL5 in craniofacial development and osteogenic differentiation of suture mesenchymal stem cells,making METTL5 a potential diagnostic and therapeutic target for craniofacial developmental diseases.