Interplay between innate and adaptive immune cells is important for the antitumor immune response. However, the tumor microenvironment may turn immune suppressive, and tumor associated macrophages are playing a role in this transition. Here, we show that CD276, expressed on tumor-associated macrophages (TAM), play a role in diminishing the immune response against tumors. Using a model of tumors induced by N-butyl-N-(4-hydroxybutyl) nitrosamine in BLCA male mice we show that genetic ablation of CD276 in TAMs blocks efferocytosis and enhances the expression of the major histocompatibility complex class II (MHCII) of TAMs. This in turn increases CD4 + and cytotoxic CD8 + T cell infiltration of the tumor. Combined single cell RNA sequencing and functional experiments reveal that CD276 activates the lysosomal signaling pathway and the transcription factor JUN to regulate the expression of AXL and MerTK, resulting in enhanced efferocytosis in TAMs. Proving the principle, we show that simultaneous blockade of CD276 and PD-1 restrain tumor growth better than any of the components as a single intervention. Taken together, our study supports a role for CD276 in efferocytosis by TAMs, which is potentially targetable for combination immune therapy. Tumor associated macrophages (TAM) are playing an active role in tumor immune evasion in multiple cancer type. Here authors show that CD276 expression by TAMs may underpin this immune-suppressive role via promoting efferocytosis and suppressing MHC class II expression, which result in decreased CD4+ and CD8 + T cell infiltration.

Liver cancer, characterized as a kind of malignant tumor within the digestive system, poses great health harm, and immune escape stands out as an important reason for its occurrence and development. Chemokines, pivotal in guiding immune cells' migration, is necessary to initiate and deliver an effective anti-tumor immune response. Therefore, understanding the chemotactic environment and identifying chemokines that regulate recruitment of immune cells to the tumor microenvironment (TME) are critical to improve current immunotherapy interventions. Herein, we report a well-defined inverse opal scaffold generated with a microfluidic emulsion template for the construction of a vascularized liver tumor model, offering insights into immune cells' recruitment. Due to the excellent 3D porous morphology of the inverse opal scaffold, human hepatocellular carcinoma cells can aggregate in the pores of the scaffold to form uniform multicellular tumor spheroids. More attractively, the vascularized liver tumor model can be achieved by constructing a 3D co-culture system involving endothelial cells and hepatocellular carcinoma cells. The results demonstrate that the 3D co-cultured tumor cells increase the neutrophil chemokines remarkably and recruit neutrophils to tumor tissues, then promote tumor progression. This approach opens a feasible avenue for realizing a vascularized liver tumor model with a reliable immune microenvironment close to that of a solid tumor of liver cancer.

As the pivotal components of the immune system, immune cells can migrate rapidly and with flexibility to fulfill their critical functions. The cytoskeleton and mechano-sensitive proteins anchored within them play a crucial role in mechano-transduction, facilitating the conversion of mechanical signals into responses within the immune cells when they encounter external stimuli. In recent years, an increasing number of studies have revealed that mechanical signals play important roles in the immune response. This article reviews advanced techniques for analyzing cellular-level mechanical forces and provides insights into the current understanding of mechanical signals in the immune system. It describes how mechano-sensitive proteins collaborate to mediate mechano-transduction and examines the profound impact of mechanical signals on immune cell functions. This review highlights the growing importance of mechano-biology in the immune system and offers a glimpse of exciting future developments in this emerging field.

The significance of biochemical cues in the tumor immune microenvironment in affecting cancer metastasis is well established, but the role of physical factors in the microenvironment remains largely unexplored. In this article, we investigated how the mechanical interaction between cancer cells and immune cells, mediated by extracellular matrix (ECM), influences immune escape of cancer cells. We focus on the mechanical regulation of macrophages’ targeting ability on two distinct types of colorectal carcinoma (CRC) cells with different metastatic potentials. Our results show that macrophages can effectively target CRC cells with low metastatic potential, due to the strong contraction exhibited by the cancer cells on the ECM, and that cancer cells with high metastatic potential demonstrated weakened contractions on the ECM and can thus evade macrophage attack to achieve immune escape. Our findings regarding the intricate mechanical interactions between immune cells and cancer cells can serve as a crucial reference for further exploration of cancer immunotherapy strategies.

Existing studies have underscored the pivotal role of N-acetyltransferase 10 (NAT10) in various cancers. However, the outcomes of protein-protein interactions between NAT10 and its protein partners in head and neck squamous cell carcinoma (HNSCC) remain unexplored. In this study, we identified a significant upregulation of RNA-binding protein with serine-rich domain 1 (RNPS1) in HNSCC, where RNPS1 inhibits the ubiquitination degradation of NAT10 by E3 ubiquitin ligase, zinc finger SWIM domain-containing protein 6 (ZSWIM6), through direct protein interaction, thereby promoting high NAT10 expression in HNSCC. This upregulated NAT10 stability mediates the enhancement of specific tRNA ac 4 C modifications, subsequently boosting the translation process of genes involved in pathways such as IL-6 signaling, IL-8 signaling, and PTEN signaling that play roles in regulating HNSCC malignant progression, ultimately influencing the survival and prognosis of HNSCC patients. Additionally, we pioneered the development of TRMC-seq, leading to the discovery of novel tRNA-ac 4 C modification sites, thereby providing a potent sequencing tool for tRNA-ac 4 C research. Our findings expand the repertoire of tRNA ac 4 C modifications and identify a role of tRNA ac 4 C in the regulation of mRNA translation in HNSCC.

Constructing proper in vitro tumor immune microenvironment (TIME) is important for cancer immune-therapy studies, while the selection of biomaterials is critical. As innate immune cells, macrophages can target and kill cancer cells in vivo at the early stage of tumor development. However, this targeting phenomenon has not been observed in vitro. Herein, a quasi-3D in vitro cell culture model is constructed to mimic TIME by integrating hydrogel collagen as extracellular matrix for cells. In the collagen-based quasi-3D in vitro system, for the first time, it is found that macrophages can be attracted toward cancer cells along the dynamically reconstructed collagen fibers. By combining traction force microscopy and customized micro-manipulator system, it is revealed that the collagen matrix-transmitted tensile force signaling precisely guides the migration of macrophages toward cancer cells. The mechano-responsiveness mechanism is related to the activation of mechanosensitive ion channels, and the induced local increase of calcium signal, which is proved to enhance the F-actin assembly and to guide the cell migration. This novel mechanism advances the understanding of the role of collagen fibers in mechanotaxis of macrophages. Taken together, it has great potential for assisting biomaterial designs in developing new drug-screening models and clinical strategies for cancer immune-therapy.

Cells in vivo are surrounded by fibrous extracellular matrix (ECM), which can mediate the propagation of active cellular forces through stressed fiber bundles and regulate various biological processes. However, the mechanisms for multi-cellular organization and collective dynamics induced by cell-ECM mechanical couplings, which are crucial for the development of novel ECM-based biomaterial for cell manipulation and biomechanical applications, remain poorly understood. Herein, the authors design an in vitro quasi-3D experimental system and demonstrate a transition between spreading and aggregating in collective organizational behaviors of discrete multi-cellular systems, induced by engineered ECM-cell mechanical coupling, with the observed phenomena and underlying mechanisms differing fundamentally from those of cell monolayers. During the process of collective cell organization, the collagen substrate undergoes reconstruction into a dense fiber network structure, which is correlated with local cellular density and consistent with observed enhanced cells' motility; and the weakening of fiber bundle formation within the hydrogel reduces cells' movement. Moreover, cells can respond to the curvature and shape of the original cell population and form different aggregation patterns. These results elucidate important physical factors involved in collective cell organization and provide important references for potential applications of biomaterials in new therapies and tissue engineering.

PCIF1 can mediate the methylation of N6,2'-O-dimethyladenosine (m6Am) in mRNA. Yet, the detailed interplay between PCIF1 and the potential cofactors and its pathological significance remain elusive. Here, we demonstrated that PCIF1-mediated cap mRNA m6Am modification promoted head and neck squamous cell carcinoma progression both in vitro and in vivo. CTBP2 was identified as a cofactor of PCIF1 to catalyze m6Am deposition on mRNA. CLIP-Seq data demonstrated that CTBP2 bound to similar mRNAs as compared with PCIF1. We then used the m6Am-Seq method to profile the mRNA m6Am site at single-base resolution and found that mRNA of TET2, a well-known tumor suppressor, was a major target substrate of the PCIF1-CTBP2 complex. Mechanistically, knockout of CTBP2 reduced PCIF1 occupancy on TET2 mRNA, and the PCIF1-CTBP2 complex negatively regulated the translation of TET2 mRNA. Collectively, our study demonstrates the oncogenic function of the epitranscriptome regulator PCIF1-CTBP2 complex, highlighting the importance of the m6Am modification in tumor progression.

NAT10 is dysregulated and plays an essential role in various types of cancers. However, the exact machenism of how NAT10 regulates cancer progression remains debatable. In this report, we show that NAT10 affects tumorigeneis mainly based on its acetylation function on tRNA. In addition, we found NAT10 regulate the ac 4 C of tRNA in cancer via interaction with RNPS1, which in turn protect NAT10 from degradation by E3 ubiquitin ligase ZSWIM6. We developed TRMC-seq method to compreshensively profile tRNA ac 4 C sites and uncovered the presence of ac 4 C in a broader range of tRNA isoacceptors than previous studies. Multi-omics analysis identified AP-1 signaling pathway as a major downstream mediator of NAT10. Mechanistically, we found NAT10 is responsible for the translation efficiency genes which contain higher ac 4 C-tRNA codon. Importantly, our genetic mouse model validated our in vitro findings of NAT10 in cancer. Our study highlights a role of NAT10 in mediating tRNA ac 4 C to regulate the translation and tumorigenesis of cancer.

Cellular collective motion in confluent epithelial monolayers is involved in many processes such as embryo development, carcinoma invasion, and wound healing. The development of new chemical strategies to achieve large-scale control of cells’ collective motion is essential for biomedical applications. Here a series of DNA nanostructures with different dimensions were synthesized and their influences on cells’ collective migration and packing behaviors in epithelial monolayers were investigated. We found that the framed DNA nanoassemblies effectively reduced the cells’ speed by increasing the rigidity of cells, while the lipid-DNA micelles had a more pronounced effect on cells’ projection area and shape factor. These DNA nanostructures all significantly enhanced the dependence of cells’ speed on their shape factor. Our results indicate that cells’ mobility in monolayers can be manipulated by chemical intercellular interactions without any genetic intervention. This may provide a new chemical strategy for tissue engineering and tumor therapy.

Synapse formation in complex neuronal network is a pivotal process for normal functioning of nervous system. Although intense research has been conducted, how neurons and axons are guided toward the target remains largely unclear. In traditional opinions, axons are directed through chemotaxis, while recently mechanotaxis has been brought up as a potential complementary mechanism, as it can provide delicately controlled signals in addition to the random diffusive chemical cues. To further explore the path-finding mechanism, a quasi-3D in vitro model for neuronal cells is constructed by integrating hydrogel collagen I as extracellular matrix (ECM), and primary mouse cortical neurons and PC12 cells are tested. It is strikingly found out that axons and neuronal cells can be precisely guided toward target neurites via ECM. By developing a label-free traction force microscopy technique, the force networks among neurons are presented, validating that the fibrous matrix-transmitted paratensile signals can assist the axon pathfinding. This precise axon guidance is related to the activation of mechanosensitive ion channels, calcium signaling, and probably the following F-actin assembly. This mechanism can potentially assist developing clinical applications and designing biomaterials in near future.

Ribosome RNA (rRNA) accounts for more than 80% of the cell's total RNA, while the physiological functions of rRNA modifications are poorly understood. Mutations of 18S rRNA m6A methyltransferase METTL5 cause intellectual disability, microcephaly, and facial dysmorphisms in patients, however, little is known about the underlying mechanisms. In this study, we identified METTL5 protein complex and revealed that METTL5 mainly interacts with RNA binding proteins and ribosome proteins. Functionally, we found that Mettl5 knockout in mESCs leads to the abnormal craniofacial and nervous development. Moreover, using Mettl5 knockout mouse model, we further demonstrated that Mettl5 knockout mice exhibit intellectual disability, recapitulating the human phenotype. Mechanistically, we found that Mettl5 maintains brain function and intelligence by regulating the myelination process. Our study uncovered the causal correlation between mis-regulated 18S rRNA m6A modification and neural function defects, supporting the important physiological functions of rRNA modifications in human diseases.

BACKGROUND/OBJECTIVES:Ribonucleotide Reductase M2 subunit (RRM2) is elevated in pancreatic cancer and involved in DNA synthesis and cell proliferation. But its specific mechanism including genetic differences and upstream regulatory pathways remains unclear.METHODS:We analyzed RRM2 expression of 178 pancreatic cancer patients in Gene Expression Profiling Interactive Analysis (GEPIA) database. Besides, more pancreatic cancer specimens were collected and detected RRM2 expression by immunohistochemistry. RRM2 knockdown by shRNA was applied for functional and mechanism analysis in vitro. Xenograft tumor growth was significantly slower by RRM2 silencing in vivo.RESULTS:It showed that high RRM2 expression had a poorer overall survival and disease free survival. RRM2 expression was higher in tumor grade 2 and 3 than grade 1. Immunohistochemistry data validated that high RRM2 expression predicted worse survival. RRM2 knockdown significantly reduced cell proliferation, inhibited colony formation and suppressed cell cycle progress. Further mechanism assay showed silencing RRM2 lead to inactivation of PI3K/AKT/mTOR pathway and inhibition of mutant p53, which induce S phase arrest and/or apoptosis. In panc-1 cells, S-phase arrest mediated by mutant p53 inhibition, p21 increase and cell cycle related proteins change. While in miapaca-2 cells, induction of apoptosis and S-phase arrest mediated by CDK1 played a coordinated role.CONCLUSION:Taken together, high RRM2 expression was associated with worse prognosis. Importantly, RRM2 knockdown deactivated PI3K/AKT/mTOR pathway, resulting in cell cycle arrest and/or apoptosis. This study shed light on the molecular mechanism of RRM2 in pancreatic tumor progression and is expected to provide a new theoretical basis for pancreatic cancer treatment.

Osteoarthritis (OA) is a common disease that endangers millions of middle-aged and elderly people worldwide. Researchers from different fields have made great efforts and achieved remarkable progress in the pathogenesis and treatment of OA. However, there is still no cure for OA. In this review, we discuss the pathogenesis of OA and summarize the current clinical therapies. Moreover, we introduce various natural and synthetic biomaterials for drug release, cartilage transplantation, and joint lubricant during the OA treatment. We also present our perspectives and insights on OA treatment in the future. We hope that this review will foster communication and collaboration among biological, clinical, and biomaterial researchers, paving the way for OA therapeutic breakthroughs.

Exosomes are cell‐derived extracellular vesicles which enclose genetic substances from their origin cells, offering a good source of biomarkers. Many efforts have been made to develop non‐invasive exosome‐based clinical diagnosis, which are urgently needed for prostate cancer, as traditional methods are criticized due to the inaccuracy and discomfort. In this study, a simple, universal process for genotyping of exosome‐derived microRNAs using nanoparticles to capture exosomes and the novel photothermal droplet digital polymerase chain reaction (ddPCR) assay to detect target molecules is presented. To detect the target sensitively and simply, the smart ddPCR thermocycling of the agarose microcarriers can be controllably realized via embedding photothermal MXene and magnetic nanoparticles composite, and then irradiating with a homemade automated near‐infrared control module. Duplex photothermal‐driven ddPCR cooperating with dual TaqMan probes enabled simultaneously and quantitatively detecting copy numbers of prostate oncogenes microRNA‐21‐5p, microRNA‐375‐3p, and metastasis microRNA‐574‐3p along with the control microRNA‐30a‐5p within the extracted exosomes. The results show that the expression levels of these biomarkers in prostate cancer cell lines PC‐3 and DU145 are 7–210 folds higher than those in healthy control cells HaCaT and HUVEC. Thus, it is believed that these versatile exosomal microRNA genotyping approaches are potentially valuable for diverse clinical applications.

BACKGROUND:Cancer cells selectively promote the translation of oncogenic transcripts to stimulate cancer progression. Although growing evidence has revealed that tRNA modifications and related genes participate in this process, their roles in head and neck squamous cell carcinoma (HNSCC) remain largely uncharacterized. Here, we sought to investigate the function and mechanisms of the transfer RNA (tRNA) N7-methylguanosine (m7 G) modification in regulating the occurrence and development of HNSCC.METHODS:Cell lost-of-function and gain-of-function assays, xenograft models, conditional knockout and knockin mouse models were used to study the physiological functions of tRNA m7 G modification in HNSCC tumorigenesis. tRNA modification and expression profiling, mRNA translation profiling and rescue assays were performed to uncover the underlying molecular mechanisms. Single-cell RNA sequencing (scRNA-seq) was conducted to explore the tumor microenvironment changes.RESULTS:The tRNA m7 G methyltransferase complex components Methyltransferase-like 1 (METTL1)/WD repeat domain 4 (WDR4) were upregulated in HNSCC and associated with a poor prognosis. Functionally, METTL1/WDR4 promoted HNSCC progression and metastasis in cell-based and transgenic mouse models. Mechanistically, ablation of METTL1 reduced the m7 G levels of 16 tRNAs, inhibiting the translation of a subset of oncogenic transcripts, including genes related to the phosphatidylinositol-3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) signaling pathway. In addition, chemical modulators of the PI3K/Akt/mTOR signaling pathway reversed the effects of Mettl1 in mouse HNSCC. Furthermore, scRNA-seq results revealed that Mettl1 knockout in mouse tumor cells altered the immune landscape and cell-cell interaction between the tumor and stromal compartment.CONCLUSIONS:The tRNA m7 G methyltransferase METTL1 was found to promote the development and malignancy of HNSCC through regulating global mRNA translation, including the PI3K/AKT/mTOR signaling pathway, and found to alter immune landscape. METTL1 could be a promising treatment target for HNSCC patients.

RNA N6-methyladenosine is a key step of posttranscriptional modulation that is involved in governing gene expression. The m 6 A modification catalyzed by Mettl3 has been widely recognized as a critical epigenetic regulation process for tumorigenic properties in various cancer cell lines, including bladder cancer. However, the in vivo function of Mettl3 in bladder cancer remains largely unknown. In our study, we found that ablation of Mettl3 in bladder urothelial attenuates the oncogenesis and tumor angiogenesis of bladder cancer using transgenic mouse model. In addition, conditional knockout of Mettl3 in K14 + bladder cancer stem cell population leads to inhibition of bladder cancer progression. Coupled with the global transcriptome sequencing and methylated RNA immunoprecipitation sequencing results, we showed that deletion of Mettl3 leads to the suppression of tyrosine kinase endothelial (TEK) and vascular endothelial growth factor A (VEGF-A) through reduced abundance of m 6 A peaks on a specific region. In addition, the depletion of Mettl3 results in the decrease in both messenger RNA (mRNA) and protein levels of TEK and VEGF-A in vitro . Taken together, Mettl3-mediated m 6 A modification is required for the activation of TEK–VEGF-A-mediated tumor progression and angiogenesis. Our findings may provide theoretical basis for bladder cancer treatment targeting Mettl3.

Methyltransferase like 13 (METTL13), a kind of methyltransferase, is implicated in protein binding and synthesis. The upregulation of METTL13 has been reported in a variety of tumors. However, little was known about its potential function in head and neck squamous cell carcinoma (HNSCC) so far. In this study, we found that METTL13 was significantly upregulated in HNSCC at both mRNA and protein level. Increased METTL13 was negatively associated with clinical prognosis. And METTL13 markedly affected HNSCC cellular phenotypes in vivo and vitro. Further mechanism study revealed that METTL13 could regulate EMT signaling pathway by mediating enhancing translation efficiency of Snail, the key transcription factor in EMT, hence regulating the progression of EMT. Furthermore, Snail was verified to mediate METTL13-induced HNSCC cell malignant phenotypes. Altogether, our study had revealed the oncogenic role of METTL13 in HNSCC, and provided a potential therapeutic strategy.

Breast cancer is one of the most common malignancy among women worldwide. Metastasis is mainly responsible for treatment failure and is the cause of most breast cancer deaths. The role of metabolism in the progression and metastasis of breast cancer is gradually being emphasized. However, the regulatory mechanisms that conduce to cancer metastasis by metabolic reprogramming in breast cancer have not been expounded. Breast cancer cells exhibit different metabolic phenotypes depending on their molecular subtypes and metastatic sites. Both intrinsic factors, such as MYC amplification, PIK3CA, and TP53 mutations, and extrinsic factors, such as hypoxia, oxidative stress, and acidosis, contribute to different metabolic reprogramming phenotypes in metastatic breast cancers. Understanding the metabolic mechanisms underlying breast cancer metastasis will provide important clues to develop novel therapeutic approaches for treatment of metastatic breast cancer.

Background About 5%–10% of the breast cancer cases have a hereditary background, and this subset is referred to as familial breast cancer (FBC). In this review, we summarize the susceptibility genes and genetic syndromes associated with FBC and discuss the FBC screening and high-risk patient consulting strategies for the Chinese population. Methods We searched the PubMed database for articles published between January 2000 and August 2021. Finally, 380 pieces of literature addressing the genes and genetic syndromes related to FBC were included and reviewed. Results We identified 16 FBC-related genes and divided them into three types (high-, medium-, and low-penetrance) of genes according to their relative risk ratios. In addition, six genetic syndromes were found to be associated with FBC. We then summarized the currently available screening strategies for FBC and discussed those available for high-risk Chinese populations. Conclusion Multiple gene mutations and genetic disorders are closely related to FBC. The National Comprehensive Cancer Network (NCCN) guidelines recommend corresponding screening strategies for these genetic diseases. However, such guidelines for the Chinese population are still lacking. For screening high-risk groups in the Chinese population, genetic testing is recommended after genetic counseling.