Microwave ablation combined with PD-L1 blockade synergistically promotes Cxcl9-mediated antitumor immunity.

Although microwave ablation (MWA) is an important curative therapy in colorectal cancer liver metastasis, recurrence still occurs clinically. Our previous studies have shown that the expression of programmed cell death 1 ligand 1 (PD-L1) is upregulated following MWA, suggesting that MWA combined with anti-PD-L1 treatment can serve as a promising clinical therapeutic strategy against cancer. Using MWA-treated preclinical mice models, MWA combined with αPD-L1 treatment decreased tumor growth and prolonged overall survival (OS). Furthermore, through flow cytometry and single-cell RNA sequencing analysis, we determined that the MWA plus αPD-L1 therapy significantly suppressed CD8+ T cell exhaustion and enhanced their effector function. A significant increase in γ-interferon (IFN-γ) stimulated transcription factors, specifically Irf8, was observed. This enhancement facilitated the polarization of tumor-associated macrophages (TAM1s and TAM2s) through the nuclear factor-κB/JAK-STAT1 signaling pathway. Furthermore, the combination therapy stimulated the production of CXC motif chemokine ligand (CXCL9) by TAM1s and tumor cells, potentially increasing the chemotaxis of CD8 T cells and Th1 cells. Knocking out Cxcl9 in MC38 tumor cells or using CXCL9 blockade enhanced tumor growth of untreated tumors and shortened OS. Taken together, our study showed that blocking the IFN-γ-Cxcl9-CD8+ T axis promoted tumor progression and discovered a potential involvement of IRF8-regulated TAMs in preventing T cell exhaustion. Collectively, we identified that the combination of MWA with anti-PD-L1 treatment holds promise as a therapeutic strategy to rejuvenate the immune response against tumors. This merits further exploration in clinical studies.

Clinicopathological and molecular features of indolent natural killer-cell lymphoproliferative disorder of the gastrointestinal tract.

AIMS: Indolent natural killer (NK) cell lymphoproliferative disorder of the gastrointestinal (GI) tract (iNKLPD) is a rare, recently recognised neoplasm. Most of the reported tumours are confined to the GI tract, while a small subset of the tumours harbour JAK3 mutations. We collected four cases of iNKLPD with the goal of adding additional information to the current knowledge of this disease regarding the clinicopathological, immunohistochemical and molecular features. METHODS AND RESULTS: Similar features including medium- to large-sized lymphoid cells with variable amounts of pale or slightly eosinophilic cytoplasm, and no evidence of EBER, TCR rearrangement were found in four cases. JAK3 K563_C565del mutation was found in one of three cases that were subjected to targeted next-generation sequencing. Unique findings of our study include one iNKLPD encountered for the first time in nasopharynx, where lesions could be inadvertently diagnosed as extranodal NK/T cell lymphoma, and one iNKLPD located in the gallbladder extended deeply into muscular and adventitial layers. Exceptional CD8-positive expression was observed in one iNKLPD. In addition, positive staining of phospho-STAT5, phospho-STAT3 and phospho-p38 were found in our cases. None of the four patients received therapy for lymphoma, but all had a benign clinical outcome during a follow-up time of 20-99 months. CONCLUSIONS: We present four iNKLPDs with clinical, immunohistochemical and molecular features similar to the reported cases, as well as some unusual characters, which expand our knowledge on this disease, and further support the neoplastic nature of iNKLPDs.

Prognostic values of tissue-resident CD8+T cells in human hepatocellular carcinoma and intrahepatic cholangiocarcinoma.

BACKGROUND: Tissue-resident CD8+T cells (CD103+CD8+T cells) are the essential effector cell population of anti-tumor immune response in tissue regional immunity. And we have reported that IL-33 can promote the proliferation and effector function of tissue-resident CD103+CD8+T cells. As of now, the immunolocalization and the prognostic values of tissue-resident CD8+T cells in human hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC) still remain to be illustrated. METHODS: In our present study, we used the tissue microarrays of HCC and ICC, the multicolor immunohistochemistry (mIHC), and imaging analysis to characterize the tissue-resident CD8+T cells in HCC and ICC tissues. The prognostic values and clinical associations were also analyzed. We also studied the biological functions and the cell-cell communication between tumor-infiltrating CD103+CD8+T cells and other cell types in HCC and ICC based on the published single-cell RNA sequencing (scRNA-seq) data. RESULTS: Our work unveiled the expressions of CD8 and CD103 and immunolocalization of tissue-resident CD8+T cells in human HCC and ICC. Elevated CD8+T cells indicated a better overall survival (OS) rate, implying that tumor-infiltrating CD8+T cells in HCC and ICC could serve as an independent prognostic factor. Moreover, the number of CD103+CD8+T cells was increased in HCC and ICC tissues compared with adjacent normal tissues. HCC patients defined as CD8highCD103high had a better OS, and the CD8lowCD103low group tended to have a poorer prognosis in ICC. Evaluation of the CD103+CD8+T-cell ratio in CD8+T cells could also be a prognostic predictor for HCC and ICC patients. A higher ratio of CD103+CD8+T cells over total CD8+T cells in HCC tissues was negatively and significantly associated with the advanced pathological stage. The percentage of higher numbers of CD103+CD8+T cells in ICC tissues was negatively and significantly associated with the advanced pathological stage. In contrast, the higher ratio of CD103+CD8+T cells over total CD8+T cells in ICC tissues was negatively and significantly associated with the advanced pathological stage. In addition, single-cell transcriptomics revealed that CD103+CD8+T cells were enriched in genes associated with T-cell activation, proliferation, cytokine function, and T-cell exhaustion. CONCLUSION: The CD103+ tumor-specific T cells signified an important prognostic marker with improved OS, and the evaluation of the tissue-resident CD103+CD8+T cells might be helpful in assessing the on-treatment response of liver cancer.

The methyltransferase METTL3 promotes tumorigenesis via mediating HHLA2 mRNA m6A modification in human renal cell carcinoma.

BACKGROUND: As an important N6-methyladenosine (m6A) regulator, abnormal expression of methyltransferase-like protein 3 (METTL3) has been reported in certain human cancers. Although some data have shown that METTL3 plays an essential role in the progression of clear-cell renal cell carcinoma RCC (ccRCC), the detailed mechanism still remains largely undetermined. METHODS: Immunohistochemistry (IHC) assay was used to examine the expression of METTL3 and its clinical implications in human ccRCC by using tissue-microarray (TMA). The cellular models based on ccRCC cell lines such as 786-O and ACHN, were established by operating METTL3 and HHLA2 via knockdown or overexpression, followed by in vitro cellular function studies and in vivo subcutaneous transplantation tumor model. RESULTS: We found that METTL3 expression in ccRCC tissues was significantly higher compared with adjacent normal tissues. We also found the overall survival (OS) of the patients with low METTL3 expression was significantly better compared with the patients with high METTL3 expression. Furthermore, HHLA2highMETTL3high could serve as a better prognostic predictor for ccRCC patients. Depletion of METTL3 could significantly inhibit the cell viability, migration, and invasion abilities in ccRCC cell lines. Cellular studies further revealed that METTL3 could regulate HHLA2 expression via m6A modification of HHLA2 mRNA. In vitro studies revealed that HHLA2 overexpression could reverse the inhibition of cellular functions mediated by METTL3 depletion. The subcutaneous transplantation tumor model confirmed that HHLA2 overexpression could reverse the inhibition of tumor growth mediated by METTL3 depletion. CONCLUSION: Our study indicated that METTL3 served as an important prognostic predictor for ccRCC patients, and we demonstrated a novel regulatory mechanism of HHLA2 by mRNA epigenetic modification via METTL3. Moreover, we found that the METTL3/HHLA2 axis could promote tumorigenesis of ccRCC. Collectively, our current findings provided new insights into the therapeutic strategy against this malignancy targeting METTL3.

LAG3 blockade coordinates with microwave ablation to promote CD8+ T cell-mediated anti-tumor immunity.

BACKGROUND: The immune checkpoint inhibitors (ICIs) combined with other therapeutic strategies have shown exciting results in various malignancies, and ICIs have now become the gold standard for current cancer treatment. In several preclinical and clinical investigations, ablation coupled with immunotherapy has proved to be quite effective. Our previous studies have shown that ablation coupled with ICI is a potential anti-cancer regimen for colorectal cancer liver metastases (CRLM). Furthermore, we have reported that following microwave ablation (MWA), the expression of LAG3 is up-regulated in tumor microenvironment (TME), indicating that LAG3 is implicated in the regulation of immunosuppressive immune response, and combination therapy of MWA and LAG3 blockade can serve as a promising therapeutic strategy against cancer. METHODS: The expression of LAG3 was investigated in this study utilizing a preclinical mouse model treated with MWA. Moreover, we monitored the tumor development and survival in mice to assess the anti-cancer effects of MWA alone or in combination with LAG3 blockade. Flow cytometry was also used to phenotype the tumor-infiltrating lymphocytes (TILs) and CD8+ T cell effector molecules. We finally analyzed the single-cell RNA sequencing (scRNA-seq) data of infiltrating CD45+ immune cells in the tumors from the MWA alone and MWA combined with LAG3 blockade groups. RESULTS: After MWA, the expression of LAG3 was up-regulated on sub-populations of TILs, and introducing LAG3 blockade to MWA postponed tumor development and extended survival in the MC38 tumor model. Flow cytometry and scRNA-seq revealed that LAG3 blockade in combination with MWA markedly boosted the proliferation and the function of CD8+ TILs, leading to altered myeloid cells in the TME. CONCLUSION: Combination therapy of LAG3 blockade and MWA was a unique therapeutic regimen for some solid tumors, and such combination therapy might reprogram the TME to an anti-tumor manner.

Increased expression of METTL3 in pancreatic cancer tissues associates with poor survival of the patients.

BACKGROUND: Methyltransferase-like 3 (METTL3) expression could be found in various normal and cancerous tissues. As of now, the clinical significance of METTL3 expression in human pancreatic cancer (PC) tissues still remains to be understood. Our present study aims to investigate the prognostic value and clinical implications of METTL3 expression in PC tissues. METHODS: The TCGA, GTEx, and GEO public databases were used to study the mRNA expression level of the m6A family members and its relationship among PC tissues and normal pancreatic tissue. The immunohistochemistry was used to analyze the difference of METTL3 expression between cancer tissues and adjacent normal tissues. The prognostic value was evaluated by using the Log-rank survival analysis and Cox model analysis. PAAD samples from TCGA and GEO databases were used to perform the immune infiltration analysis and gene set enrichment analysis based on the genes that were highly correlated with METTL3. RESULTS: Based on the analysis of TCGA, GTEx, and GEO public database, we found that the m6A family members showed a higher correlation in PC tissues compared to normal pancreatic tissues, and the mRNA expression level of the m6A family members showed a significant difference between PC tissues and adjacent normal tissues. Moreover, scRNA-seq data indicated that METTL3 showed a higher expression level in malignant epithelial cells. Our immunohistochemistry results also confirmed that the intensity of METTL3 immunostaining in PC tissues was significantly higher than that in adjacent normal tissues (P = 0.015). The overall survival (OS) of PC patients with high expression of METTL3 protein were significantly poorer than those with low expression of METTL3 protein (HR = 1.788, 95% CI 1.071-2.984, P = 0.026). Further analysis of PC data from the database showed that METTL3 expression was associated with a variety of tumor-infiltrating immune cells and was involved in m6A modification and metabolism in PC tissues. CONCLUSION: Increased METTL3 expression at the protein level could be found in PC tissues, suggesting that the METTL3 expression was involved in the progression of PC and could serve as an important marker for prognostic prediction of this malignancy.

[Value of S100A8 in evaluating the prognosis of children with acute lymphoblastic leukemia].

OBJECTIVE: To study the association between S100A8 expression and prognosis in children with acute lymphoblastic leukemia (ALL). METHODS: The clinical data of 377 children with ALL who were treated with the CCLG-2008-ALL regimen were retrospectively reviewed. ELISA and PCR were used to measure serum protein levels and mRNA expression of S100A8. The Kaplan-Meier method was used for survival analysis and a Cox regression analysis was also performed. RESULTS: The children were followed up for 56 months, and the overall survival rate of the 377 children was 89.1%. The prednisone good response group had significantly lower S100A8 protein and mRNA levels than the prednisone poor response group (P<0.01). In the children with standard or median risk, both S100A8 protein and mRNA levels were associated with event-free survival rate (P<0.05). There were significant differences in S100A8 protein and mRNA levels between the children with different risk stratifications (P<0.01). The children who experienced events had significantly higher S100A8 protein and mRNA levels than those who did not (P<0.01). The Kaplan-Meier survival analysis and the Cox regression model suggested that S100A8 overexpression was an independent risk factor for the prognosis of children with ALL. CONCLUSIONS: High S100A8 expression may be associated with the poor prognosis of children with ALL and is promising as a new marker for individualized precise treatment of children with ALL.

Transient and dynamic DNA supercoiling potently stimulates the leu-500 promoter in Escherichia coli.

The inactive prokaryotic leu-500 promoter (Pleu-500) contains a single A-to-G point mutation in the -10 region of the leucine operon promoter, which causes leucine auxotrophy. This promoter can be activated by (-) DNA supercoiling in Escherichia coli topA strains. However, whether this activation arises from global, permanent, or transient, dynamic supercoiling is still not fully understood. In this article, using a newly established in vivo system carrying a pair of divergently coupled promoters, i.e. an IPTG-inducible promoter and Pleu-500 that control the expression of lacZ and luc (the firefly luciferase gene), respectively, we demonstrate that transient, dynamic (-) DNA supercoiling provided by divergent transcription in both wild-type and topA strains can potently activate Pleu-500 We found that this activation depended on the promoter strength and the length of RNA transcripts, which are functional characteristics of transcription-coupled DNA supercoiling (TCDS) precisely predicted by the twin-supercoiled domain model of transcription in which a (+) supercoiled domain is produced ahead of the RNA polymerase and a (-) supercoiled domain behind it. We also demonstrate that TCDS can be generated on topologically open DNA molecules, i.e. linear DNA molecules, in Escherichia coli, suggesting that topological boundaries or barriers are not required for the production of TCDS in vivo This work demonstrates that transient, dynamic TCDS by RNA polymerases is a major chromosome remodeling force in E. coli and greatly influences the nearby, coupled promoters/transcription.

Zinc Depletion by TPEN Induces Apoptosis in Human Acute Promyelocytic NB4 Cells.

BACKGROUND/AIMS: The effects of zinc signaling on proliferation or apoptosis of leukemia cells remain elusive. In the present study, we used N, N, N', N'-tetrakis-(2-pyridylmethyl)-ethylene-diamine (TPEN), a membrane-permeable zinc chelator, to evaluate the effect of zinc depletion on survival and apoptosis of NB4 acute promyelocytic leukemia (APL) cells. METHODS: The pro-apoptotic effects of TPEN on NB4 cells were examined by flow cytometry, and observed using an optical microscope. Intracellular labile zinc, nitric oxide (NO) or reactive oxygen species (ROS) changes caused by TPEN were measured by flow cytometry. We then explored possible roles of the crosstalk between intracellular labile zinc signaling and nitric oxide signaling in TPEN-triggered apoptosis. RESULTS: we found that TPEN induced apoptosis in NB4 APL cells in a dosage-dependent manner. We further demonstrated that TPEN triggered apoptosis by attenuating intracellular zinc and nitric oxide signaling in NB4 cells. Both exogenous zinc supplement and the nitric donor sodium nitroprusside (SNP) pre-incubation reversed TPEN-mediated inhibition of intracellular NO and Zn2+ signaling, and rescued NB4 cells from apoptosis. CONCLUSION: These results suggest for the first time that crosstalk between zinc signaling and nitric oxide pathway is essential for the survival of NB4 cells. TPEN induces apoptosis in NB4 cells via negatively regulating intracellular NO and Zn2+ signaling. Our in vitro data suggest that zinc depletion by TPEN may be a potential therapeutic strategy for APL.

[Painless skin nodules and ecchymosis in a school-aged girl].

A 7-year-old girl was admitted to Xiangya Hospital due to systemic lymphadenectasis for 2 months and skin ecchymosis for 3 days. Nine months ago, the girl experienced painless nodules in the left lower extremity with no apparent causes. Three months later, dermatorrhagia and ecchymosis occurred in many regions such as the periocular areas, conjunctiva, oral mucosa, perineal area, and groin, with a "raccoon sign" in both eyes; superficial lymphadenectasis and hepatosplenomegaly were also observed in many regions. The pathological sections for the skin nodules showed malignant tumors in lymphohematopoietic cells, and in combination with clinical manifestations, immunohistochemistry, and positive results for CD4, CD56, and CD123 by bone marrow flow cytometry, the girl was diagnosed with blastic plasmacytoid dendritic cell neoplasm. Then high-risk ALL regimen was applied as the chemotherapy for this girl. At present, the girl has been followed up for 3 months; ecchymosis has disappeared, and the enlarged lymph nodes have shrunk. No abnormal cells have been found in bone marrow morphological examination, and bone marrow flow cytometry has shown that primitive precursor cells account for 1.5% and express CD33, CD34, CD123, and CD117.

TIGIT Blockade Reshapes the Tumor Microenvironment Based on the Single-cell RNA-Sequencing Analysis.

SUMMARY: Immune checkpoint blockade therapy is a pivotal approach in treating malignant tumors. TIGIT has emerged as a focal point of interest among the diverse targets for tumor immunotherapy. Nonetheless, there is still a lack of comprehensive understanding regarding the immune microenvironment alterations following TIGIT blockade treatment. To bridge this knowledge gap, we performed single-cell sequencing on mice both before and after the administration of anti-TIGIT therapy. Our analysis revealed that TIGIT was predominantly expressed on T cells and natural killer (NK) cells. The blockade of TIGIT exhibited inhibitory effects on Treg cells by downregulating the expression of Foxp3 and reducing the secretion of immunosuppressive cytokines. In addition, TIGIT blockade facilitated the activation of NK cells, leading to an increase in cell numbers, and promoted cDC1 maturation through the secretion of XCL1 and Flt3L. This activation, in turn, stimulated the TCR signaling of CD8 + T cells, thereby enhancing their antitumor effect. Consequently, anti-TIGIT therapy demonstrated substantial potential for cancer immunotherapy. Our research provided novel insights into future therapeutic strategies targeting TIGIT for patients with cancer.

Precursor exhausted CD8+T cells in colorectal cancer tissues associated with patient's survival and immunotherapy responsiveness.

Exhausted CD8+T cells represent a distinct cellular lineage that emerges during both chronic infections and cancers. Recent studies have shown that persistent antigen exposure can drive the differentiation of precursor exhausted CD8+T cells, termed Tpex cells, which are characterized as TCF-1+PD-1+CD8+T cells. Elevated Tpex cell frequencies in the tumor microenvironment (TME) are associated with improved overall survival (OS) in cancer patients and heightened responsiveness to anti-PD-1 therapy. In our present study, we utilized multi-color immunohistochemistry (mIHC) to determine the localization and clinical implications of tumor-infiltrating Tpex cells within the TME of human colorectal cancer (CRC) tissues. We also conducted a multi-omics integrative analysis using single-cell RNA sequencing (scRNA-seq) data derived from both the murine MC38 tumor model and human CRC tissues. This analysis helped delineate the transcriptional and functional attributes of Tpex cells within the CRC TME. Furthermore, we employed spatial transcriptome sequencing data from CRC patients to investigate the interactions between Tpex cells and other immune cell subsets within the TME. In conclusion, our study not only established a method for Tpex cell detection using mIHC technology but also confirmed that assessing Tpex cells within the CRC TME could be indicative of patients' survival. We further uncovered the transcriptional and functional characteristics of Tpex cells in the TME and ascertained their pivotal role in the efficacy of immunotherapy against CRC.

Artificial intelligence-based assessment of PD-L1 expression in diffuse large B cell lymphoma.

Diffuse large B cell lymphoma (DLBCL) is an aggressive blood cancer known for its rapid progression and high incidence. The growing use of immunohistochemistry (IHC) has significantly contributed to the detailed cell characterization, thereby playing a crucial role in guiding treatment strategies for DLBCL. In this study, we developed an AI-based image analysis approach for assessing PD-L1 expression in DLBCL patients. PD-L1 expression represents as a major biomarker for screening patients who can benefit from targeted immunotherapy interventions. In particular, we performed large-scale cell annotations in IHC slides, encompassing over 5101 tissue regions and 146,439 live cells. Extensive experiments in primary and validation cohorts demonstrated the defined quantitative rule helped overcome the difficulty of identifying specific cell types. In assessing data obtained from fine needle biopsies, experiments revealed that there was a higher level of agreement in the quantitative results between Artificial Intelligence (AI) algorithms and pathologists, as well as among pathologists themselves, in comparison to the data obtained from surgical specimens. We highlight that the AI-enabled analytics enhance the objectivity and interpretability of PD-L1 quantification to improve the targeted immunotherapy development in DLBCL patients.

Collective diffusion model for ion conduction through microscopic channels.

Ion conduction through microscopic channels is of central importance in both biology and nanotechnology. To better understand the current-voltage (I-V) dependence of ion channels, here we describe and prove a collective diffusion model that quantitatively relates the spontaneous ion permeation at equilibrium to the stationary ionic fluxes driven by small voltages. The model makes it possible to determine the channel conductance in the linear I-V range from equilibrium simulations without the application of a voltage. To validate the theory, we perform molecular-dynamics simulations on two channels-a conical-shaped nanopore and the transmembrane pore of an α-hemolysin-under both equilibrium and nonequilibrium conditions. The simulations reveal substantial couplings between the motions of cations and anions, which are effectively captured by the collective coordinate in the model. Although the two channels exhibit very different linear ranges in the I-V curves, in both cases the channel conductance at small voltages is in reasonable agreement with the prediction from the equilibrium simulation. The simulations also suggest that channel charges, rather than geometric asymmetry, play a more prominent role in current rectification.

Erlotinib binds both inactive and active conformations of the EGFR tyrosine kinase domain.

Erlotinib and gefitinib, tyrosine kinase inhibitors used to block EGFR (epidermal growth factor receptor) signalling in cancer, are thought to bind only the active conformation of the EGFR-TKD (tyrosine kinase domain). Through parallel computational and crystallographic studies, we show in the present study that erlotinib also binds the inactive EGFR-TKD conformation, which may have significant implications for its use in EGFR-mutated cancers.

ErbB3/HER3 intracellular domain is competent to bind ATP and catalyze autophosphorylation.

ErbB3/HER3 is one of four members of the human epidermal growth factor receptor (EGFR/HER) or ErbB receptor tyrosine kinase family. ErbB3 binds neuregulins via its extracellular region and signals primarily by heterodimerizing with ErbB2/HER2/Neu. A recently appreciated role for ErbB3 in resistance of tumor cells to EGFR/ErbB2-targeted therapeutics has made it a focus of attention. However, efforts to inactivate ErbB3 therapeutically in parallel with other ErbB receptors are challenging because its intracellular kinase domain is thought to be an inactive pseudokinase that lacks several key conserved (and catalytically important) residues-including the catalytic base aspartate. We report here that, despite these sequence alterations, ErbB3 retains sufficient kinase activity to robustly trans-autophosphorylate its intracellular region--although it is substantially less active than EGFR and does not phosphorylate exogenous peptides. The ErbB3 kinase domain binds ATP with a K(d) of approximately 1.1 microM. We describe a crystal structure of ErbB3 kinase bound to an ATP analogue, which resembles the inactive EGFR and ErbB4 kinase domains (but with a shortened alphaC-helix). Whereas mutations that destabilize this configuration activate EGFR and ErbB4 (and promote EGFR-dependent lung cancers), a similar mutation conversely inactivates ErbB3. Using quantum mechanics/molecular mechanics simulations, we delineate a reaction pathway for ErbB3-catalyzed phosphoryl transfer that does not require the conserved catalytic base and can be catalyzed by the "inactive-like" configuration observed crystallographically. These findings suggest that ErbB3 kinase activity within receptor dimers may be crucial for signaling and could represent an important therapeutic target.

The CXCL10/CXCR3 Pathway Contributes to the Synergy of Thermal Ablation and PD-1 Blockade Therapy against Tumors.

As a practical local therapeutic approach to destroy tumor tissue, thermal ablation can activate tumor-specific T cells via enhancing tumor antigen presentation to the immune system. In the present study, we investigated changes in infiltrating immune cells in tumor tissues from the non-radiofrequency ablation (RFA) side by analyzing single-cell RNA sequencing (scRNA-seq) data of tumor-bearing mice compared with control tumors. We showed that ablation treatment could increase the proportion of CD8+T cells and the interaction between macrophages and T cells was altered. Another thermal ablation treatment, microwave ablation (MWA), increased the enrichment of signaling pathways for chemotaxis and chemokine response and was associated with the chemokine CXCL10. In addition, the immune checkpoint PD-1 was especially up-regulated in the infiltrating T cells of tumors on the non-ablation side after thermal ablation treatment. Combination therapy of ablation and PD-1 blockade had a synergistic anti-tumor effect. Furthermore, we found that the CXCL10/CXCR3 axis contributed to the therapeutic efficacy of ablation combined with anti-PD-1 therapy, and activation of the CXCL10/CXCR3 signaling pathway might improve the synergistic effect of this combination treatment against solid tumors.

N6-methyladenosine demethylase FTO promotes growth and metastasis of gastric cancer via m6A modification of caveolin-1 and metabolic regulation of mitochondrial dynamics.

Gastric cancer (GC) is the fifth most common tumor and the third most deadly cancer worldwide. N6-methyladenosine (m6A) modification has been reported to play a regulatory role in human cancers. However, the exact role of m6A in GC remains largely unknown, and the dysregulation of m6A on mitochondrial metabolism has never been studied. In the present study, we demonstrated that FTO, a key demethylase for RNA m6A modification, was up-regulated in GC tissues, especially in tissues with liver metastasis. Functionally, FTO acted as a promoter for the proliferation and metastasis in GC. Moreover, FTO enhanced the degradation of caveolin-1 mRNA via its demethylation, which regulated the mitochondrial fission/fusion and metabolism. Collectively, our current findings provided some valuable insights into FTO-mediated m6A demethylation modification and could be used as a new strategy for more careful surveillance and aggressive therapeutic intervention.

TIGIT Blockade Exerts Synergistic Effects on Microwave Ablation Against Cancer.

Background: Combination immunotherapy based on immune checkpoint inhibitors (ICIs) has shown great success in the treatment of many types of cancers and has become the mainstream in the comprehensive treatment of cancers. Ablation in combination with immunotherapy has achieved tremendous efficacy in some preclinical and clinical studies. To date, our team proved that ablation in combination with ICIs was a promising antitumor therapeutic strategy for the liver metastasis of colorectal cancer (CRC). Moreover, we found that the expression of T cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT) expression was up-regulated after microwave ablation (MWA), indicating that TIGIT was involved in immunosuppression, and the combination of MWA and TIGIT blockade represented a potential clinical treatment strategy. Methods: In the present study, we examined the expression of TIGIT using a preclinical mouse model treated with MWA. Moreover, we evaluated the antitumor functions of MWA alone or in combination with TIGIT blockade by monitoring tumor growth and survival of the mice. Besides, we also detected the numbers of tumor-infiltrating lymphocytes (TILs), and effector molecules of CD8+ T cells using flow cytometry. Finally, we analyzed the single-cell RNA sequencing (scRNA-seq) data from the MWA and MWA plus anti-TIGIT groups. Results: The expression of TIGIT in various immune cells was up-regulated after MWA, and the addition of TIGIT blockade to MWA prolonged survival and delayed tumor growth in the MC38 tumor model. Taken together, our findings showed that TIGIT blockade in combination with MWA significantly promoted the expansion and functions of CD8+ TILs and reshaped myeloid cells in the tumor microenvironment (TME) using flow cytometry and scRNA-seq analysis. Conclusions: TIGIT blockade in combination with MWA was a novel treatment strategy for the liver metastasis of CRC, and this combination therapy could reprogram the TME toward an antitumor environment.

IL1R2 promotes tumor progression via JAK2/STAT3 pathway in human clear cell renal cell carcinoma.

Clear cell renal cell carcinoma (ccRCC) is known as the most aggressive subtype of genitourinary cancers. The lack of effective therapies has prompted us to further explore the complex network of genes involved in ccRCC tumor progression and metastasis and to seek new biomarkers and therapeutic strategies to improve clinical outcomes. Interleukin-1 receptor type 2 (IL1R2), a decoy receptor of IL-1, is found to be differentially expressed in various tumors types recently. However, the role of IL1R2 in ccRCC has not been documented. Herein, we found that the expression of IL1R2 in ccRCC tissues was significantly increased as the tumor's Furman pathological grade was elevated. Compared to lower IL1R2 expression, ccRCC patients with high IL1R2 expression had a significantly worse OS rate. IL1R2 could serve as an independent prognostic predictor for ccRCC patients. Depletion of IL1R2 could inhibit cell proliferation, migration, invasion, and cell cycle arrest at the G1 phase, while overexpression of IL1R2 could reverse this effect. Moreover, depletion of IL1R2 led to changes and enrichment of several signaling pathways, as shown by RNA sequencing. We subsequently verified that Janus kinase 2 / signal transducer and activator of transcription 3 (JAK2/STAT3) pathway was involved in the IL1R2 mediated regulation of cellular functions of ccRCC cells and these functions were acted by the intracellular domain of IL1R2, not the extracellular domain. Our findings suggested that IL1R2 could serve as a potential therapeutic target for ccRCC progression and metastasis via its regulation of the JAK2/STAT3 signaling pathway.