LINC00525 enhances ZNF460-regulated CD24 expression through the sponge miR-125a-5p to promote malignant progression of breast cancer.

INTRODUCTION: CD24 is a highly glycosylated glycosylphosphatidylinositol anchored membrane protein that plays an important role in tumor progression. The aim of this study was to investigate the effect of abnormal expression of CD24 on the proliferation, migration and invasion of breast cancer (BC) cells, and the molecular mechanism of regulating CD24 expression in breast cancer. METHODOLOGY: The bioinformatics method was used to predict the expression level of CD24 in BC and its relationship with the occurrence and development of BC. IHC, RT-qPCR and WB were used to detect the expression of CD24 in BC tissues and cells. The proliferation of CD24 was evaluated by CCK-8 and colony formation assay, and the migration and invasion of CD24 were evaluated by wound healing and transwell. In addition, the effect of CD24 on the malignancy of BC in vivo was further evaluated by subcutaneous tumorigenesis assay. Molecular mechanisms were measured by luciferase reporter assays, biotin-labeled miRNA pull-down assay, RIP, and western blotting. RESULTS: The results show that CD24 is highly expressed in breast cancer tissues and cell lines, and knockdown of CD24 in vivo and in vitro can inhibit the proliferation, migration and invasion of BC cells. Mechanistically, the transcription factor ZNF460 promotes its expression by binding to the CD24 promoter, and the expression of ZNF460 is regulated by miR-125a-5p, which inhibits its expression by targeting the 3'UTR of ZNF460. In addition, LINC00525 acts as a ceRNA sponge to adsorb miR-125a-5p and regulate its expression. CONCLUSIONS: Overexpression of CD24 is involved in the development and poor prognosis of BC, which can be used as a potential target for the treatment of BC and provide a theoretical basis for the treatment of BC.

The effect of LNCRNA SHANK3 on the malignant development of gastric cancer cells by regulating the miR-4530/MNX1.

Gastric cancer (GC) has become the first malignant tumor with highest incidence rate and mortality of cancer in China, finding therapeutic targets for gastric cancer is of great significant for improving the survival rate of patients with GC. Recently, many of studies have shown that LncRNAs is involved in multiple biological progresses in the development of GC. This study, we screened for abnormally high expression of LncSHANK3 in GC through the TCGA database, and found that LncSHANK3 sponge adsorbs miR-4530, further competing with MNX1 and binding to miR-4530. We demonstrated the interaction between LncSHANK3 and miR-4530 through luciferase reporting analysis, with miR-4530 negatively regulating MNX1.Through CCK8, colony formation, transwell, and wound healing assays, it was found that LncSHANK3 affects the occurrence of GC through cell proliferation, migration and invasion. In conclusion, LncSHANK3/miR-4530/MNX1 axis is a potential mechanism for the treatment of GC.

MAGE-A11 is a potential prognostic biomarker and immunotherapeutic target in gastric cancer.

Gastric cancer poses a serious threat to human health and affects the digestive system. The lack of early symptoms and a dearth of effective identification methods make diagnosis difficult, with many patients only receiving a definitive diagnosis at a malignant stage, causing them to miss out on optimal therapeutic interventions. Melanoma-associated antigen-A (MAGE-A) is part of the MAGE family and falls under the cancer/testis antigen (CTA) category. The MAGE-A subfamily plays a significant role in tumorigenesis, proliferation and migration. The expression, prognosis and function of MAGE-A family members in GC, however, remain unclear. Our research and screening have shown that MAGE-A11 was highly expressed in GC tissues and was associated with poor patient prognosis. Additionally, MAGE-A11 functioned as an independent prognostic factor in GC through Cox regression analysis, and its expression showed significant correlation with both tumour immune cell infiltration and responsiveness to immunotherapy. Our data further indicated that MAGE-A11 regulated GC cell proliferation and migration. Subsequently, our findings propose that MAGE-A11 may operate as a prognostic factor, having potential as an immunotherapy target for GC.

MKL-1 suppresses ferroptosis by activating system Xc- and increasing glutathione synthesis.

Chemotherapy is a standard method in traditional treatment for gastric cancer. It is well known that the anti-tumor effects of chemotherapy are achieved mainly through the direct killing of cancer cells via apoptosis. However, chemotherapy often fails due to drug resistance. Therefore, non-apoptotic cell death induction by ferroptosis has recently been proposed as a new therapeutic modality to ablate cancer. In this study, we determined the role of MKL-1 in ferroptosis. In vitro and in vivo experiments showed that inhibition of MKL-1 expression significantly enhanced cell sensitivity to ferroptosis-inducing agents. It functions by targeting system Xc- to affect the synthesis of GSH in cells. Therefore, we developed an exosome-based therapeutic approach targeting MKL-1, which provides a novel insight into the treatment of gastric cancer.

Dissecting transcription of the 8q24-MYC locus in prostate cancer recognizes the equilibration between androgen receptor direct and indirect dual-functions.

BACKGROUND: Androgen receptor (AR) activation and repression dual-functionality only became known recently and still remains intriguing in prostate cancer (PCa). MYC is a prominent oncogene that functionally entangles with AR signaling in PCa. Further exploration of AR regulatory mechanisms on MYC gene transcription bears clinical and translation significance. METHODS: Bioinformatics analysis of PCa cell line and clinical RNA-Seq and ChIP-Seq (chromatin immunoprecipitation-sequencing) datasets to anchor interactions of AR and MYC transcriptional networks. ChIP-qPCR and 3C (chromosome conformation capture) analyses to probe MYC distal regulation by AR binding sites (ABSs). CRISPR/Cas9-mediated genome-editing to specify functions of ABS within the 8q24-MYC locus on androgen-mediated MYC transcription. Global FoxA1 and HoxB13 distribution profiling to advance AR transcriptional mechanisms. RESULTS: Here we recognize AR bi-directional transcription mechanisms by exploiting the prominent 8q24-MYC locus conferring androgen hyper-sensitivity. At ~ 25 Kb downstream of the MYC gene, we identified an undefined ABS, P10. By chromatin analyses, we validated androgen-dependent spatial interaction between P10 and MYC-Promoter (MYC-Pro) and temporal epigenetic repression of these MYC-proximal elements. We next designed a CRISPR/Cas9-mediated double genomic knock-out (KO) strategy to show that P10-KO slightly lessened androgen-elicited MYC transrepression in LNCaP-AR cells. In similar genomic editing assays, androgen-mediated MYC repression became slightly deepened upon KO of P11, an ABS in the PVT1 gene locus highly enriched in AR-binding motifs and peaks. We also investigated multiple ABSs in the established PCAT1 super-enhancer that distally interacts with MYC-Pro for transactivation, with each KO pool consistently shown to relieve androgen-elicited MYC repression. In the end, we systemically assessed androgen effects in the 8q24-MYC locus and along PCa genome to generalize H3K27ac and BRD4 re-distribution from pioneer factors (FoxA1 and HoxB13) to AR sites. CONCLUSION: Together, we reconciled these observations by unifying AR dual-functions that are mechanistically coupled to and equilibrated by co-factor redistribution.

NRP1 regulates autophagy and proliferation of gastric cancer through Wnt/ß-catenin signaling pathway.

Gastric cancer possesses high lethality rate, and its complex molecular mechanisms of pathogenesis lead to irrational treatment outcomes. Autophagy plays a dual role in cancer by both promoting and suppressing the cancer. However, the role of autophagy in gastric cancer is still vague. Therefore, in this study, we first obtained autophagy-related genes from the Human Autophagy Database, and then applied consensus clustering analysis to analyse the molecular subtypes of gastric cancer samples in the TCGA database. The genes obtained after subtyping were then applied to construct risk prognostic model. Following this, PCA and tSNE assessed risk scores with good discriminatory ability for gastric cancer samples. The results of Cox regression analysis and time-dependent ROC curve analysis indicated that the model had good risk prediction ability. Finally, NRP1 was selected as the final study subject in the context of expression pairwise analysis, Kaplan-Meier curves and external validation of the GEO dataset. In vitro experiments showed that NRP1 has the ability to regulate the proliferation and autophagy of gastric cancer cells by affecting the Wnt/ß-catenin signalling pathway. Similarly, in vivo experiments have shown that NRP1 can affect tumour growth in vivo. We therefore propose that NRP1 can be used as both a prognostic factor and a therapeutic target through the regulation of autophagy in gastric cancer.

Androgen receptor and MYC transcriptomes are equilibrated in multilayer regulatory circuitries in prostate cancer.

BACKGROUND: The discovery of androgen receptor (AR) having transrepression effects completes the circle of its functionalities as a typical transcription factor, which intrinsically bears dual functions of activation and repression linked to co-factor competition and redistribution. Indeed, AR dual functions are exemplified by locus-wide regulation of the oncogenic 8q24-MYC region. METHODS: RT-qPCR assay and public RNA-profiling datasets were used to assess MYC transcription in androgen-sensitive cell lines. Public ChIP-seq and RNA-Seq datasets were computed to evaluate AR-MYC direct and indirect signatures. Gene sets in typical MYC and AR pathways were monitored to validate their cross-talks. Bio-informatics and chromosome conformation capture (3C) assay were performed in the AR gene locus to examine androgen-elicited distal regulation. Finally, co-factor re-distribution were globally tracked between AR and MYC binding sites. RESULTS: In this report, we found MYC responded negatively to androgen with hypersensitivity, rivaling AR natural functions as an innate androgen effector. Furthermore, both direct and indirect AR and MYC transcriptional programs were actively in equilibration. With established androgen-mediated versus MYC-mediated gene subsets, we validated AR and MYC pathways were both bidirectional and extensively entangled. In addition, we determined that the AR gene locus resembled the MYC gene region and both loci were androgen-repressed via epigenetics and chromatin architectural alterations. Significantly, transcriptional factor profiling along the prostate cancer (PCa) genome exposed that PCa transcriptomes were dynamically equilibrated between AR-binding site and MYC-binding site. CONCLUSION: Together, our findings stratified AR-MYC interactions that are extensively wired and intricately organized to compensate for essential PCa transcriptional programs and neutralize excessive signaling.

A novel transcription factor SIPA1: identification and verification in triple-negative breast cancer.

Transcription factors (TFs) regulate the expression of genes responsible for cell growth, differentiation, and responses to environmental factors. In this study, we demonstrated that signal-induced proliferation-associated 1 (SIPA1), known as a Rap-GTPase-activating protein, bound DNA and served as a TF. Importin ß1 was found to interact with SIPA1 upon fibronectin treatment. A TGAGTCAB motif was recognized and bound by DNA-binding region (DBR) of SIPA1, which was confirmed by electrophoretic mobility shift assay. SIPA1 regulated the transcription of multiple genes responsible for signal transduction, DNA synthesis, cell adhesion, cell migration, and so on. Transcription of fibronectin 1, which is crucial for cell junction and migration of triple-negative breast cancer (TNBC) cells, was regulated by SIPA1 in a DBR-dependent manner both in vivo and in vitro. Furthermore, single-cell transcriptome sequencing analysis of specimens from a metastatic TNBC patient revealed that SIPA1 was highly expressed in metastatic TNBC. Hence, this study demonstrated that SIPA1 served as a TF, promoting TNBC migration, invasion, and metastasis.

GNPNAT1 promotes the stemness of breast cancer and serves as a potential prognostic biomarker.

Glucosamine­phosphate N­acetyltransferase 1 (GNPNAT1) is a member of the acetyltransferase superfamily, related to general control non­depressible 5 (GCN5). It has been documented that GNPNAT1 expression is increased in lung cancer, whereas its involvement in breast cancer (BC) remains to be further investigated. The present study aimed to evaluate the expression levels of GNPNAT1 in BC and its effect on BC stem cells (BCSCs). The Cancer Genome Atlas (TCGA) database was used for the analysis of the expression of GNPNAT1 and its clinical significance. Cox regression and logistic regression analyses were used to evaluate prognosis­related factors. The GNPNAT1­binding protein network was constructed using the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) application. The biological signaling pathways implicated in GNPNAT1 were investigated through function enrichment analysis including Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and gene set enrichment analysis. The single­sample GSEA method was used to investigate the connection between the level of immune infiltration and GNPNAT1 expression in BC. GNPNAT1 expression was upregulated in patients with BC and was significantly associated with a poor prognosis. GNPNAT1 and its co­expressed genes were mostly enriched in nuclear transport, Golgi vesicle transport, ubiquitin­like protein transferase activity and ribonucleoprotein complex binding, as determined using functional enrichment analysis. GNPNAT1 expression was positively associated with Th2 cells and T­helper cells, and negatively associated with plasmacytoid dendritic cells, CD8+ T­cells and cytotoxic cells. Additionally, the GNPNAT1 expression levels were considerably increased in BCSCs. GNPNAT1 knockdown markedly decreased the stemness ability of SKBR3 and Hs578T cells, including the production of CSC markers and mammosphere or clone formation, while GNPNAT1 overexpression increased the stemness level. Hence, the findings of the present study demonstrate that GNPNAT1 may be exploited as a novel prognostic biomarker and therapeutic target for BC.

GRB10 is a novel factor associated with gastric cancer proliferation and prognosis.

GRB10 and its family members GRB7 and GRB14 were important adaptor proteins. They regulated many cellular functions by interacting with various tyrosine kinase receptors and other phosphorus-containing amino acid proteins. More and more studies have shown that the abnormal expression of GRB10 is closely related to the occurrence and development of cancer. In our current research, expression data for 33 cancers from the TCGA database was downloaded for analysis. It was found that GRB10 was up-regulated in cholangiocarcinoma, colon adenocarcinoma, head and neck squamous carcinoma, renal chromophobe, clear renal carcinoma, hepatocellular carcinoma, lung adenocarcinoma, lung squamous carcinoma, gastric adenocarcinoma and thyroid carcinoma. Especially in gastric cancer, the high GRB10 expression was closely associated with poorer overall survival. Further research showed that the knockdown of GRB10 inhibited proliferation and migration ability in gastric cancer. Also, there was a potential binding site for miR-379-5p on the 3'UTR of GRB10. Overexpression of miR-379-5p in gastric cancer cells reduced GRB10-regulated gastric cancer proliferation and migration capacity. In addition, we found that tumor growth was slower in a mice xenograft model with knock down of GRB10 expression. These findings suggested that miR-379-5p suppresses gastric cancer development by downregulating GRB10 expression. Therefore, miR-379-5p and GRB10 were expected to be potential targets for the treatment of gastric cancer.

ncR2Met (lncR2metasta v2.0): An updated database for experimentally supported ncRNAs during cancer metastatic events.

Non-coding RNAs (ncRNAs) are widely involved in cancer metastatic events (CMEs, e.g., cancer cell invasion, intravasation, extravasation, proliferation), which collaboratively accelerate tumor spread and cause high patient mortality. In early 2020, we developed a manually curated database named 'lncR2metasta' to provide a comprehensive repository for long ncRNA (lncRNA) regulation during CMEs. We updated this database by supplementing other two important ncRNA types, microRNAs (miRNAs) and circular RNAs (circRNAs), for their involvement during CMEs after a thorough manual curation from published studies. ncR2metasta documents 1565 lncRNA-associated, 882 miRNA-associated, and 628 circRNA-associated entries for ncRNA-CME associations during 50 CMEs across 63 human cancer subtypes. ncR2Met has a concise web interface for researchers to easily browse, search and download as well as to submit novel ncRNA-CME associations. We anticipated that it could be a valuable resource, which will significantly improve our understanding of ncRNA functions in metastasis. It is freely available at http://ncr2met.wchoda.com.

NUF2 Promotes Breast Cancer Development as a New Tumor Stem Cell Indicator.

Multiple new subtypes of breast cancer (BRCA) are identified in women each year, rendering BRCA the most common and rapidly expanding form of cancer in females globally. NUF2 has been identified as a prognostic factor in various human cancers, regulating cell apoptosis and proliferation. However, its role in BRCA prognosis has not been clarified. This study explored the role of NUF2 in breast cancer development and prognosis using informatic analysis combined with in vivo intracellular studies. Through the online website TIMER, we evaluated the transcription profile of NUF2 across a variety of different cancer types and found that NUF2 mRNA was highly expressed in BRCA patients. Its transcription level was found to be related to the subtype, pathological stage, and prognosis of BRCA. The R program analysis showed a correlation of NUF2 with cell proliferation and tumor stemness in the BRCA patient samples. Subsequently, the association between the NUF2 expression level and immune cell infiltration was analyzed using the XIANTAO and TIMER tools. The results revealed that NUF2 expression was correlated with the responses of multiple immune cells. Furthermore, we observed the effect of NUF2 expression on tumor stemness in BRCA cell lines in vivo. The experimental results illuminated that the overexpression of NUF2 statistically upregulated the proliferation and tumor stemness ability of the BRCA cell lines MCF-7 and Hs-578T. Meanwhile, the knockdown of NUF2 inhibited the abilities of both cell lines, a finding which was verified by analyzing the subcutaneous tumorigenic ability in nude mice. In summary, this study suggests that NUF2 may play a key role in the development and progression of BRCA by affecting tumor stemness. As a stemness indicator, it has the potential to be one of the markers for the diagnosis of BRCA.

LncRNA BCAR4 promotes migration, invasion, and chemo-resistance by inhibiting miR-644a in breast cancer.

BACKGROUND: Metastasis and drug resistance of breast cancer have become a barrier to treating patients successfully. Long noncoding RNAs (lncRNAs) are known as vital players in cancer development and progression.  METHODS: The RT-qPCR were used to detect the gene expression. Colony formation assay, would healing assay, and transwell assay were performed to investigate oncogenic functions of cells. CCK8 assay was used to detect the cell viability. Western blot was applied to detect the protein level. Dual-luciferase reporter assay was used to determine the relationship between molecules. Mouse orthotopic xenograft tumor models were established to evaluate the effects of BCAR4 on tumor growth and metastasis in vivo.  RESULTS: LncRNA BCAR4 was significantly increased in breast cancer patients' tissues and plasma and upregulated in breast cancer cell lines. BCAR4 upregulation was correlated with the TNM stages and decreased after surgical removal of breast tumors. Silencing of BCAR4 suppressed breast cancer cell colony formation, migration, invasion, and xenograft tumor growth and promoted chemo-sensitivity. Mechanistically, BCAR4 facilitates breast cancer migration and invasion via the miR-644a-CCR7 axis of the MAPK pathway. BCAR4 promotes ABCB1 expression indirectly by binding to and down-regulating miR-644a to induce chemo-resistance in breast cancer. CONCLUSIONS: Our findings provide insights into the oncogenic role of BCAR4 and implicate BCAR4 as a potential diagnostic biomarker and a promising therapeutic agent to suppress metastasis and inhibit chemo-resistance of breast cancer.

Mitochondria-Targeted Nanosystem with Reactive Oxygen Species-Controlled Release of CO to Enhance Photodynamic Therapy of PCN-224 by Sensitizing Ferroptosis.

The apoptosis-resistant mechanism of photodynamic therapy (PDT) usually results in limited therapeutic efficacy. The development of new strategies for sensitizing targeted ferroptosis that bypass apoptosis resistance is of great significance to improve the antitumor efficacy of PDT. In this study, a novel amphiphilic copolymer whose main chain contains reactive oxygen species (ROS)-responsive groups and the end of side chains contains triphenylphosphine is synthesized, to encapsulate porphyrinic metal-organic framework PCN-224 via self-assembly which are hydrothermally synthesized by coordination of zirconium (IV) with tetra-kis(4-caboxyphenyl) porphyrin, and loaded carbon monoxide releasing molecule 401 (CORM-401) by their hollow structures (PCN-CORM), and finally, surface-coated with hyaluronic acid. The nanosystem can sequentially localize to mitochondria which is an important target to induce apoptosis and ferroptosis in cancer cells. Upon excitation with near-infrared light, PCN-224 is activated to produce amounts of ROS, and simultaneously triggers the rapid intracellular release of CO. More importantly, the released CO can sensitize ferroptosis and promote apoptosis to significantly enhance the antitumor efficacy of PCN-224 both in vitro and in vivo. These results illustrate that the mitochondria-targeted drug delivery system combined PDT with CO leads to an effective antitumor efficacy, which maybe a promising way to enhance the treatment efficiency of PDT.

Acid/reduction dual-sensitive amphiphilic graft polyurethane with folic acid and detachable poly(ethylene glycol) as anticancer drug delivery carrier.

In order to not only improve the stability of nanomicelles in blood circulation but also promote the cellular uptake in tumors and rapidly release the encapsulated drugs in tumor cells, a kind of acid/reduction dual-sensitive amphiphilic graft polyurethane with folic acid and detachable poly(ethylene glycol) (FA-PUSS-gimi-mPEG) was synthesized by grafting folic acid and monomethoxy poly(ethylene glycol) to the polyurethane side chain. FA-PUSS-gimi-mPEG could self-assemble in aqueous solution to form negatively charged nanomicelles, which endowed them good stability under normal physiological condition. Using ultraviolet-visible spectrometer (UV-vis) and dynamic light scattering (DLS), it was found that the hydrophilic poly(ethylene glycol) layer of FA-PUSS-gimi-mPEG micelles could be detached due to the cleavage of benzoic-imine bond under slightly acidic condition, which resulted in reversing the charge of the micellar surface and exposing folic acid to the micellar surface. FA-PUSS-gimi-mPEG micelles could load doxorubicin (DOX), moreover the drug release rate was faster at pH 5.0 and 10 mM glutathione (GSH) than that under normal physiological condition. The results of cell experiments further demonstrated that FA-PUSS-gimi-mPEG micelles had acid/reduction dual-sensitive property. The changes in the structure of FA-PUSS-gimi-mPEG micelles could enhance the cellular uptake under acid condition and the micelles could accelerate the drug release in tumor cells due to the presence of disulfide bonds in the polymer. Therefore, FA-PUSS-gimi-mPEG micelles could efficiently deliver anticancer drug into tumor cells and enhance the inhibition of cellular proliferation through multi-effect synergy.

MKL-1-induced PINK1-AS overexpression contributes to the malignant progression of hepatocellular carcinoma via ALDOA-mediated glycolysis.

Aldolase A (ALDOA), an important metabolic enzyme in the glycolytic pathway, plays an important role in regulating tumour metabolism. In this study, we investigated the expression pattern of ALDOA in hepatocellular carcinoma (HCC) and its biological role in tumour progression. Bioinformatics analysis, western blot (WB) and RT-qPCR were performed to detect the relative expression of ALDOA in HCC tissues and cell lines. A loss-of-function approach was used to investigate the biological function of ALDOA. The role of ALDOA on glycolysis was assessed by WB, glucose and lactate assay kits and a nude mouse xenograft model. Luciferase reporter experiment, chromatin immunoprecipitation and WB were performed to elucidate the underlying molecular. The expression level of ALODA was up-regulated in HCC tissues and cell lines. High ALDOA levels were associated with poorer patient overall survival. Mechanistic studies suggest that ALDOA is a direct target of miR-34a-5p, which can inhibit glycolysis in hepatocellular carcinoma cells by targeting the 3'UTR of ALDOA. PINK1 antisense RNA (PINK1-AS) competitively sponged miR-34a-5p to increase ALDOA expression by antagonizing miR-34a-5p-mediated ALDOA inhibition. MKL-1 acted as a transcription factor to promote the expression of PINK1-AS and ALDOA, thus promoting the deterioration of HCC cells. This study shows that high expression of ALDOA contributes to the development and poor prognosis of hepatocellular carcinoma and will be a target and potential prognostic biomarker for the treatment of HCC.

MAGE-A3 regulates tumor stemness in gastric cancer through the PI3K/AKT pathway.

Gastric cancer remains a malignant disease of the digestive tract with high mortality and morbidity worldwide. However, due to its complex pathological mechanisms and lack of effective clinical therapies, the survival rate of patients after receiving treatment is not satisfactory. A increasing number of studies have focused on cancer stem cells and their regulatory properties. In this study, we first constructed a co-expression network based on the WGCNA algorithm to identify modules with different degrees of association with tumor stemness indices. After selecting the most positively correlated modules of the stemness index, we performed a consensus clustering analysis on gastric cancer samples and constructed the co-expression network again. We then selected the modules of interest and applied univariate COX regression analysis to the genes in this module for preliminary screening. The results of the screening were then used in LASSO regression analysis to construct a risk prognostic model and subsequently a sixteen-gene model was obtained. Finally, after verifying the accuracy of the module and screening for risk genes, we identified MAGE-A3 as the final study subject. We then performed in vivo and in vitro experiments to verify its effect on tumor stemness and tumour proliferation. Our data supports that MAGE-A3 is a tumor stemness regulator and a potent prognostic biomarker which can help the prediction and treatment of gastric cancer patients.

B cell deficiency promotes the initiation and progression of lung cancer.

Currently commercialized CAR-T cell therapies targeting CD19 and BCMA show great efficacy to cure B cell malignancies. However, intravenous infusion of these CAR-T cells severely destroys both transformed and normal B cells in most tissues and organs, in particular lung, leading to a critical question that what the impact of normal B cell depletion on pulmonary diseases and lung cancer is. Herein, we find that B cell frequency is remarkably reduced in both smoking carcinogen-treated lung tissues and lung tumors, which is associated with advanced cancer progression and worse patient survival. B cell depletion by anti-CD20 antibody significantly accelerates the initiation and progression of lung tumors, which is mediated by repressed tumor infiltration of T cells and macrophage elimination of tumor cells. These findings unveil the overall antitumor activity of B cells in lung cancer, providing novel insights into both mechanisms underlying lung cancer pathogenesis and clinical prevention post CAR-T cell therapy.