BackgroundAlthough immune checkpoint blockade (ICB) has been proven to achieve a persistent therapeutic response in various tumor types, only 20%–40% of patients benefit from this treatment. Radiotherapy (RT) can enhance tumor immunogenicity and improve the ICB response, but the outcome achieved by combining these two modalities remains clinically unsatisfactory. We previously uncovered that lysine-specific demethylase 4C (KDM4C) is a regulator of radiosensitivity in lung cancer. However, the role of KDM4C in antitumor immunity has not yet been investigated.MethodsInfiltrating immune cells in our mouse tumor model were screened by flow cytometry. An in vivo subcutaneous transplanted tumor model and in vitro conditioned culture model were constructed to detect the quantitative and functional changes in CD8+ T cells. RNA sequencing and chromatin immunoprecipitation-PCR assays were used to explore the downstream regulatory mechanism of KDM4C in antitumor immunity. A C57BL/6 mouse tumor model was developed to evaluate the efficacy and safety of a triple therapy (the KDM4C-specific inhibitor SD70 plus RT and an anti-PD-L1 antibody) in lung cancer in vivo.ResultsGenetical or pharmacological inhibition of KDM4C specifically increased CD8+ T cell infiltration; promoted the proliferation, migration and activation of CD8+ T cells; and alleviated CD8+ T cell exhaustion in mouse tumor tissues. Mechanistically, KDM4C inhibition increased the binding of H3K36me3 to the CXCL10 promoter region, thus inducing CXCL10 transcription and enhancing the CD8+ T cell mediated antitumor immune response. More importantly, among the tested regimens, the triple therapy achieved the best therapeutic efficacy with tolerable toxicity in lung cancer.ConclusionsOur data reveal a crucial role for KDM4C in antitumor immunity in lung cancer and indicate that targeting KDM4C in combination with radioimmunotherapy might be a promising synergistic strategy in lung cancer.

REV1 is the central member of the family of TLS polymerases, which participate in various DNA damage repair and tolerance pathways and play a significant role in maintaining genomic stability. However, the role of REV1 in tumors is rarely reported. In this study, we found that the expression of REV1 was significantly upregulated in lung cancer tissues compared with matched adjacent tissues and was associated with poor prognosis. Functional experiments demonstrated that REV1 silencing decreased the growth and proliferation capacity of lung cancer cells. Mechanistically, REV1 upregulated the expression of SERTAD2 in a Rad18-dependent manner, thereby promoting lung carcinogenesis. A novel REV1 inhibitor, JH-RE-06, suppressed lung tumorigenesis in vivo and in vitro and was shown to be safe and well tolerated. Our study confirmed that REV1 is a potential diagnostic marker and therapeutic target for lung cancer and that JH-RE-06 may be a safe and efficient therapeutic agent for NSCLC.

Background Radiation-induced lung injury (RILI) is the most common and serious complication of chest radiotherapy. However, reported radioprotective agents usually lead to radiation resistance in tumor cells. The key to solving this problem is to distinguish between the response of tumor cells and normal lung epithelial cells to radiation damage. Methods RNA-Seq was used to recognize potential target of alleviating the progression of RILI as well as inhibiting tumor growth. The activation of NLRP3 inflammasome in lung epithelial cells was screened by qRT-PCR, western blotting, immunofluorescence, and ELISA. An in vivo model of RILI and in vitro conditioned culture model were constructed to evaluate the effect of NLRP3/interleukin-1β on fibroblasts activation. ROS, ATP, and (NADP)+/NADP(H) level in lung epithelial cells was detected to explore the mechanism of NLRP3 inflammasome activation. The lung macrophages of the mice were deleted to evaluate the role of lung epithelial cells in RILI. Moreover, primary cells were extracted to validate the results obtained from cell lines. Results NLRP3 activation in epithelial cells after radiation depends on glycolysis-related reactive oxygen species accumulation. DPYSL4 is activated and acts as a negative regulator of this process. The NLRP3 inflammasome triggers interleukin-1β secretion, which directly affects fibroblast activation, proliferation, and migration, eventually leading to lung fibrosis. Conclusions Our study suggests that NLRP3 inflammasome activation in lung epithelial cells is essential for radiation-induced lung injury. These data strongly indicate that targeting NLRP3 may be effective in reducing radiation-induced lung injury in clinical settings.

Radioresistance remains a major obstacle to efficacious radiotherapy in non–small‐cell lung cancer (NSCLC). DNA replication proteins are novel targets for radiosensitizers. POLQ is a DNA polymerase involved in DNA damage response and repair. We found that POLQ is overexpressed in NSCLC and is clinically correlated with high tumor stage, poor prognosis, increased tumor mutational burden, and ALK and TP5 mutation status; POLQ inhibition impaired lung tumorigenesis. Notably, POLQ expression was higher in radioresistant lung cancer cells than in wild‐type cancer cells. Moreover, POLQ expression was further increased in radioresistant cells after radiation. Enhanced radioresistance is through a prolonged G2/M phase and faster repair of DNA damage, leading to reduced radiation‐induced apoptosis. Novobiocin (NVB), a POLQ inhibitor, specifically targeted cancer cells. Genetic knockdown of POLQ or pharmacological inhibition by NVB decreased radioresistance in lung adenocarcinoma while causing little toxicity to normal pulmonary epithelial cells. In conclusion, POLQ is a promising and practical cancer‐specific target to impair tumorigenesis and enhance radiosensitivity in NSCLC.

Radioresistance is a major cause of radiotherapy failure among patients with cervical cancer (CC), the fourth most common cause of cancer mortality in women worldwide. Traditional CC cell lines lose intra-tumoral heterogeneity, posing a challenge for radioresistance research. Meanwhile, conditional reprogramming (CR) maintains intra-tumoral heterogeneity and complexity, as well as the genomic and clinical characteristics of original cells and tissues. Three radioresistant and two radiosensitive primary CC cell lines were developed under CR conditions from patient specimens, and their characteristics were verified via immunofluorescence, growth kinetics, clone forming assay, xenografting, and immunohistochemistry. The CR cell lines had homogenous characteristics with original tumor tissues and maintained radiosensitivity in vitro and in vivo, while also maintaining intra-tumoral heterogeneity according to single-cell RNA sequencing analysis. Upon further investigation, 20.83% of cells in radioresistant CR cell lines aggregated in the G2/M cell cycle phase, which is sensitive to radiation, compared to 38.1% of cells in radiosensitive CR cell lines. This study established three radioresistant and two radiosensitive CC cell lines through CR, which will benefit further research investigating radiosensitivity in CC. Our present study may provide an ideal model for research on development of radioresistance and potential therapeutic targets in CC.

Background Diacylglycerol kinase α (DGKA) is the first member discovered from the diacylglycerol kinase family, and it has been linked to the progression of various types of tumors. However, it is unclear whether DGKA is linked to the development of lung cancer. Methods We investigated the levels of DGKA in the lung cancer tissues. Cell growth assay, colony formation assay and EdU assay were used to examine the effects of DGKA‐targeted siRNAs/shRNAs/drugs on the proliferation of lung cancer cells in vitro. Xenograft mouse model was used to investigate the role of DGKA inhibitor ritanserin on the proliferation of lung cancer cells in vivo. The downstream target of DGKA in lung tumorigenesis was identified by RNA sequencing. Results DGKA is upregulated in the lung cancer cells. Functional assays and xenograft mouse model indicated that the proliferation ability of lung cancer cells was impaired after inhibiting DGKA. And cyclin D3(CCND3) is the downstream target of DGKA promoting lung cancer. Conclusions Our study demonstrated that DGKA promotes lung tumorigenesis by regulating the CCND3 expression and hence it can be considered as a potential molecular biomarker to evaluate the prognosis of lung cancer patients. What's more, we also demonstrated the efficacy of ritanserin as a promising new medication for treating lung cancer.