Mouse Lewis Lung Carcinoma Research Articles

Aqueous extract of Taxus chinensis var. mairei targeting CD47 enhanced antitumor effects in non-small cell lung cancer

Immunoglobulin protein CD47 is overexpressed in malignant tumor cells, allowing them to evade host immunity mainly by inhibiting macrophage-mediated phagocytosis. Taxus chinensis var. mairei (TC) exhibits high antitumor efficacy with low toxicity and notable cost-effectiveness. However, it is unknown whether aqueous extract of TC (AETC) is an immunomodulator that mediates antitumor efficacy. In this study, we aimed to elucidate the critical role of CD47 degradation in the treatment of AETC in non-small cell lung cancer (NSCLC) cells. A mouse Lewis lung carcinoma model was developed to determine whether the administration of AETC, as an anti-CD47 antibody, in combination with anti-PD-1 could synergistically inhibit tumor growth and promote a peripheral immune response. AETC treatment downregulated CD47 levels in NSCLC cells and Lewis tumor xenograft mice. Furthermore, treatment enhanced immunity against NSCLC by triggering CD47 ubiquitination and degradation, promoting macrophage-mediated tumor cell phagocytosis, and activating CD8+ T cells. The present study empirically demonstrated, for the first time, that AETC exerts antitumor properties as an immunomodulator. Our findings present AETC as a promising alternative or adjuvant treatment in lung cancer therapy.

PGC-1α overexpression is not sufficient to mitigate cancer cachexia in either male or female mice.

Cancer cachexia (CC) accounts for 20%-40% of cancer-related deaths. Mitochondrial aberrations have been shown to precede muscle atrophy in different atrophy models, including cancer. Therefore, this study investigated potential protection from the cachectic phenotype through overexpression of peroxisome proliferator-activated receptor γ coactivator-1 α (PGC-1α). First, to establish potential of mitochondria-based approaches we showed that the mitochondrial antioxidant MitoTEMPO (MitoT) attenuates myotube atrophy induced by Lewis lung carcinoma (LLC) cell conditioned media. Next, cachexia was induced in muscle-specific PGC-1α overexpressing (MCK-PCG1α) or wildtype (WT) littermate mice by LLC implantation. MCK-PCG1α did not protect LLC-induced muscle mass loss. In plantaris, Atrogin mRNA content was 6.2-fold and ∼11-fold greater in WT-LLC vs WT-phosphate-buffered saline (PBS) for males and females, respectively (p<0.05). MitoTimer red:green ratio for male PGC was ∼65% higher than WT groups (p<0.05), with ∼3-fold more red puncta in LLC than PBS (p<0.05). Red:green ratio was ∼56% lower in females WT-LLC vs PGC-LLC (p<0.05). In females, no change in red puncta was noted across conditions. Lc3 mRNA content was ∼73% and 2-fold higher in male and female LLC mice, respectively, vs PBS (p<0.05). While MitoT could mitigate cancer-induced atrophy in vitro, PGC-1α overexpression was insufficient to protect muscle mass and mitochondrial health in vivo despite mitigation of cachexia-associated signaling pathways.

Experimental photodynamic therapy in the treatment of lung tumor.

e20515 Background: Study of the effect of photodynamic therapy (PDT) with Photoditazine using a high-energy laser at various periods after tumor transplantation on the dynamics of growth of experimental Lewis lung carcinoma in mice. Methods: The study included 176 male C57Bl6 mice weighing 18-20 g with Lewis lung carcinoma (LLC) transplanted subcutaneously. The animals received experimental PDT sequential overlapping of fields of influence (662 nm, 3 W, Photoditazine 25 mg/kg, 300 J/cm2). Animals received PDT on day 11 after the transplantation (experimental series I) and on day 21 (experimental series II). Experimental groups were divided in dependence on the exposure area (to the primary tumor -1gr, thorax (area of metastases)-2 gr and to both zones-3 gr). Animals with tumors without PDT were used as controls. Results: PDT with Photoditazine using the 3W laser stimulated the growth of primary tumor node. The degree of stimulation depended on the time of PDT. Increase in tumor sizes differed already on day 7 after PDT at various periods of the LCC growth. During PDT on the 11th day from the moment of tumor inoculation, the percentage of growth on the 7th day after the end of treatment was 60.7; 69.6 and 86.7% in groups 1, 2 and 3, respectively. In the groups of animals that underwent PDT on the 21st day of the growth of the grafted tumor on the 7th day after the end of treatment, the percentage of tumor growth was 20; 35.6 and 24.4% in groups 1, 2 and 3, respectively. Increase in the median survival was registered in experimental animals with PDT on 22.6% compared to control. A smaller increase in tumor volume was observed in animals receiving PDT to the primary tumor, and the group receiving therapy to both areas was in between. Conclusions: The study was shown that with an earlier initiation of PDT, a greater stimulation of tumor growth was revealed than with therapy at a later date. The revealed characteristics of the development of experimental LLC at PDT exposure allows further selection of parameters for photodynamic therapy regimens.

Anti-Angiogenic and Cytotoxicity Effects of Selachyl Alcohol Analogues

The active ingredients in the shark liver oil (SLO) mixture were found to be a group of etherlinked glycerol known as alkylglycerols (AKGs). During the last century, initial clinical use of the SLO mixture was for treating leukemias and later preventing radiation sickness from cancer x-ray therapy. Selachyl alcohol is one of the most abundant AKGs in the SLO mixture and it displayed strong activity in reducing lung metastasis number on a model of grafted tumor in mice (Lewis lung carcinoma cells). In this study, selachyl alcohol analogue containing methoxyl (7), gem-difluorinated (8), azide (9) and hydroxyl (10) group at the 12 position in the alkyl chain were synthesized and compared regarding their cytotoxicity and anti-migratory effects on Human Umbilical Vein Endothelial Cell line. AKGs 7-10 were synthesized according to the literature procedure. The cytotoxicity of the studied AKGs was evaluated by the MTT test and Human Umbilical Vein Endothelial Cell line (HUVEC) was used as an in vitro model to evaluate their anti-migratory effects. The four AKGs have substantially the same toxicity threshold (≥ 12 μM), whereas they have an anti-migratory activity significantly different on endothelial cells. AKGs 9 and 10 significantly reduce the chemotactic migration induced by VEGF, but analogue (10) containing the hydroxyl group at the 12 position in the alkyl chain was the most potent anti-VEGF inhibitor. We presented here a series of four synthetic selachyl alcohol analogues, among which AKGs 9 and 10 showed the ability to inhibit endothelial cell migration. The relationship structures and anti-VEGF effects of these analogues were also evaluated and discussed. Unnatural synthesized AKGs could be explored as one new source of anticancer agents.

Effects of contraction and feeding on skeletal muscle protein synthesis during the initiation of cachexia

Muscle contraction and feeding are potent regulators of skeletal muscle protein synthesis. Cancer cachexia can suppress muscle protein synthesis through Akt/mTORC1 signaling suppression. Cachexia also suppresses acute contraction‐induced muscle protein synthesis. However, the cancer environment’s impact on the combined feeding and contraction activation of protein synthesis during the initiation of cachexia is not well understood. Therefore, we examined the cancer environment’s effect on the muscle protein synthesis response to an acute bout of muscle contraction with and without feeding.METHODSMale C57BL/6J (B6; N=36) were injected with 1 x 106 Lewis Lung Carcinoma (LLC) cells or PBS subcutaneously in the right flank and were monitored for up to 30 days. Following an overnight 12hr fast, mice were given ad libitum access to a food pellet for 1hr (fed) or fasted for an additional hour (fast). Subsequently, mice were subjected to low‐frequency electrical stimulation (LFES) for 30 minutes and sacrificed 3hrs post. Puromycin was injected 30min before sacrifice for protein synthesis measurements. Gastrocnemius muscle was examined for protein expression and values normalized to the contralateral limb.RESULTSIn PBS mice, LFES induced rpS6 (9.5‐fold) and protein synthesis (4.7‐fold). LFES induced rpS6 (1.7‐fold) and protein synthesis (0.9‐fold) in LLC mice. Overall, rpS6 and protein synthesis were lower in the LLC mice compared to PBS. Feeding increased muscle rpS6 and protein synthesis in PBS mice (p&lt;0.001) but not in LLC (p=0.821 and p=0.642) mice. Feeding and LFES synergistically induce rpS6 and protein synthesis in PBS mice; however, this was not present in LLC mice.CONCLUSIONWe report that contraction’s ability to increase muscle protein synthesis is suppressed in mice initiating cachexia. The ability for feeding to increase muscle protein synthesis is also suppressed in mice initiating cachexia. Notably, the combined effects of feeding and contraction were insufficient to synergistically improve muscle protein synthesis as in healthy mice. Future studies should determine why feeding was not sufficient to induce muscle protein synthesis in mice initiating cachexia.

The effect of the iron chelator Deferasirox in combination with Cisplatin chemotherapy against lung carcinoma

The preferred treatment for patients with lung carcinoma (LC) is platinum‐based regimens, eg., Cisplatin (CisPt). Unfortunately, despite improvements in LC outcomes, many of these tumors metastasize and develop resistance against such Pt‐drugs, inducing abysmally low survival prognosis. Due to this, there is an urgent need to develop alternative therapies for LC mostly focused on overcome or diminish chemoresistance and inhibit the metastatic spread. FDA‐approved drugs which target cancer metabolic pathways are considered as repurposing drugs that could diminish these adverse effects. Deferasirox (Def), an FDA‐approved iron chelation therapy, is a drug under study for cancer therapy due to iron plays a key role in cell growth and energy production in cancer. Herein, we determined the effect of deferasirox (Def) alone and in combination with CisPt on the genes related to chemoresistance and metastasis in LC cells. Viability assay results showed that Def has synergistic cytotoxic effects in combination with CisPt after 24 h of incubation in A549 LC cells. qPCR gene expression studies showed that Def induced a significant downregulation of EGFR, VEGF, MMP9, Pgp, P53, NDRG1, CHD4 genes in A549 cells. In addition, we determined that Def induce the production of reactive oxygen species in LC. Furthermore, in in vivo studies performed in Lewis Lung Carcinoma mouse model, Def co‐administered with CisPt showed tumor size reduction. The results obtained from this study will impact the field of lung cancer therapy adding knowledge on the Def cellular mechanisms and genetic regulation against chemoresistance and metastasis processes.

181P Anlotinib enhances the antitumor activity of high-dose irradiation combined with anti-PD-L1 by potentiating the tumor immune microenvironment in murine lung cancer

Radioimmunotherapy has become one of the most promising strategies for cancer treatment. Preclinical and clinical studies have demonstrated that antiangiogenic therapy can improve the efficacy of immunotherapy and sensitize radiotherapy through a variety of mechanisms. However, it is undefined whether angiogenesis inhibitors can enhance the effect of radioimmunotherapy. In this study, we aim to explore the role of anlotinib (AL3818) on the combination of radiotherapy and immune checkpoint inhibitors in Lewis lung carcinoma mouse.

32P Anlotinib enhances the antitumor activity of high-dose irradiation combined with anti-PD-L1 by potentiating the tumor immune microenvironment in murine lung cancer

Radioimmunotherapy has become one of the most promising strategies for cancer treatment. Preclinical and clinical studies have demonstrated that antiangiogenic therapy can improve the efficacy of immunotherapy and sensitize radiotherapy through a variety of mechanisms. However, it is undefined whether angiogenesis inhibitors can enhance the effect of radioimmunotherapy. In this study, we aim to explore the role of anlotinib (AL3818) on the combination of radiotherapy and immune checkpoint inhibitors in Lewis lung carcinoma mouse.

반하 추출물의 종양연관대식세포 조절을 통한 암세포 이동능 저해 효과

The tuber of Pinellia ternata (Thunb.) Brei (TPT) used in traditional Oriental medicine for the treatment of cough, sputum, vomiting, and insomnia, possesses antioxidant, antibacterial, and anti-inflammatory effects. Although recent studies have reported the anticancer effects of TPT in several cancer cells, it is still unclear whether TPT regulates tumor-associated macrophage (TAM) characterized by the immunosuppressive M2 macrophage phenotype. Our results showed that the ethanol extract of TPT (ETPT) suppressed the migration of RAW264.7 mouse macrophage cells and THP-1 human monocytes differentiated into macrophages towards the conditioned media (CM) collected from lung cancer cells, suggesting that ETPT would attenuate the recruitment of macrophages into tumors. In addition, ETPT suppressed the interleukin (IL)-4 or IL-6-induced M2 macrophage polarization in RAW264.7 cells. ETPT treatment not only downregulated the mRNA expression of M2 macrophage markers including arginase-1, mannose receptor C type 1 (MRC-1), and IL-10, but also inhibited the phosphorylation of signal transducer and activator of transcription 3 (STAT3) and STAT6, general regulators of M2 macrophage polarization. Finally, the transwell assay results showed that the CM from M2-polarized RAW264.7 cells increased the migration of mouse lewis lung carcinoma (LLC) cells, while those from RAW264.7 cells co-treated with ETPT and IL-6 significantly reduced the migration of LLC cells. Taken together, our observations clearly demonstrate that ETPT suppressed the cancer cell migration by regulating macrophage recruitment and M2 macrophage polarization.

Folate-Decorated Cross-Linked Cytochrome c Nanoparticles for Active Targeting of Non-Small Cell Lung Carcinoma (NSCLC).

The folate receptor alpha (FR), which is overexpressed in solid tumors including NSCLC, can be utilized for active tumor targeting to afford more effective cancer therapies. In this context, cytochrome c (Cyt c) has drawn attention to cancer research because it is non-toxic, yet, when delivered to the cytoplasm of cancer cells, can kill them by inducing apoptosis. Cyt c nanoparticles (NPs, 169 ± 9 nm) were obtained by solvent precipitation with acetonitrile, and stabilized by reversible homo-bifunctional crosslinking to accomplish a Cyt-c-based drug delivery system that combines stimulus-responsive release and active targeting. Cyt c was released under intracellular redox conditions, due to an S–S bond in the NPs linker, while NPs remained intact without any release under extracellular conditions. The NP surface was decorated with a hydrophilic folic acid–polyethylene glycol (FA–PEG) polymer for active targeting. The FA-decorated NPs specifically recognized and killed cancer cells (IC50 = 47.46 µg/mL) that overexpressed FR, but showed no toxicity against FR-negative cells. Confocal microscopy confirmed the preferential uptake and apoptosis induction of our NPs by FR-positive cancer cells. In vivo experiments using a Lewis lung carcinoma (LLC) mouse model showed visible NP accumulation within the tumor and inhibited the growth of LLC tumors.

High farnesoid X receptor expression predicts favorable clinical outcomes in PD‑L1low/negative non‑small cell lung cancer patients receiving anti‑PD‑1‑based chemo‑immunotherapy.

Anti-programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1)-directed immunotherapy has revolutionized the treatment of advanced non-small cell lung cancer (NSCLC). However, predictive biomarkers are still lacking, particularly in identifying PD-L1low/negative patients who will benefit from immunotherapy. It was previously reported that farnesoid X receptor (FXR) downregulated PD-L1 expression in NSCLC, and that FXRhighPD-L1low mouse Lewis lung carcinoma tumors showed an increased susceptibility to PD-1 blockade compared with mock tumors. At present, whether the FXRhighPD-L1low phenotype predicts clinical response to immunotherapy in patients with NSCLC remains unclear. Herein, a retrospective study was conducted to examine the expression levels of FXR, PD-L1 and CD8+ T cells by immunohistochemistry in a cohort of 149 patients with NSCLC receiving anti-PD-1-based chemo-immunotherapy. The results revealed that high FXR and PD-L1 expression levels were associated with higher objective response rates (ORR) in all patients. High PD-L1 expression also indicated superior progression-free survival (PFS). Interestingly, an inverse correlation was identified between FXR and PD-L1 expression in specimens with NSCLC. Subgroup analysis revealed that high FXR expression was associated with a higher ORR, as well as longer PFS and overall survival (OS) in PD-L1low patients. Cox multivariate analysis revealed that high FXR expression was an independent predictor for PFS and OS in PD-L1low patients. Tumor microenvironment evaluation revealed a statistically significant decrease of infiltrating CD8+ T cells in FXRhigh specimens with NSCLC. Overall, the present study proposed an FXRhighPD-L1low signature as a candidate predictor of response to anti-PD-1-based chemo-immunotherapy in PD-L1low/negative patients with NSCLC, providing evidence that could be used to broaden the patients benefitting from immunotherapy.

Atractylenolide II inhibits tumor-associated macrophages (TAMs)-induced lung cancer cell metastasis

Objective M2-like tumor-associated macrophages (TAMs) play a crucial role in promoting tumor proliferation, angiogenesis, and metastasis. In the current study, we investigated the relationship between macrophage polarization and the antitumor effect of Atractylenolide II (AT-II) in lung cancer cells. Materials and methods Cell viability, migration, and invasion were determined by MTT assay, wound healing assay, and transwell assay, respectively. Flow cytometry analysis showed the percentage of CD206+ cells. Gene expression was determined by real-time PCR, western blotting, and immunofluorescence staining. Lewis lung carcinoma mouse xenograft and metastasis models were used to examine the effects of AT-II on lung cancer in vivo. Results AT-II (2.5 and 5 µM) did not cause significant inhibition of A549 cell viability but markedly inhibited IL-4/IL-13-induced M2-like polarization, evidenced by the decreased expression of the M2 surface marker CD206, down-regulation of specific M2-marker genes (Arg-1, IL-10 and TGF-β) as well as inhibition of M2 macrophages-mediated invasion and migration of A549 cells. In addition, AT-II inhibited IL-4/IL-13-induced activation of the STAT6 signaling pathway that is vital in the M2-like polarization of macrophages. In animal models, administration of AT-II (50 mg kg−1, i.g., QD for 21 days) significantly inhibited tumor growth, reduced pulmonary metastatic nodules, and down-regulated the percentages of M2 macrophages (F4/80+ and CD206+) in total macrophages (F4/80+) in tumor tissues and pulmonary metastatic nodules. Conclusions AT-II effectively inhibits M2-like polarization, thereby inhibiting lung cancer cell metastasis both in vivo and in vitro, revealing a novel potential strategy for the antitumor effect of AT-II.

Anlotinib Enhances the Antitumor Activity of High-Dose Irradiation Combined with Anti-PD-L1 by Potentiating the Tumor Immune Microenvironment in Murine Lung Cancer.

Background Radioimmunotherapy has become one of the most promising strategies for cancer treatment. Preclinical and clinical studies have demonstrated that antiangiogenic therapy can improve the efficacy of immunotherapy and sensitize radiotherapy through a variety of mechanisms. However, it is undefined whether angiogenesis inhibitors can enhance the effect of radioimmunotherapy. In this study, we aim to explore the role of anlotinib (AL3818) on the combination of radiotherapy and immune checkpoint inhibitors in Lewis lung carcinoma mouse. Methods C57BL/6 mouse subcutaneous tumor model was used to evaluate the ability of different treatment regimens in tumor growth control. Immune response and immunophenotyping including the quantification and activation were determined by flow cytometry, multiplex immunofluorescence, and multiplex immunoassay. Results Triple therapy (radiotherapy combined with anti-PD-L1 and anlotinib) increased tumor-infiltrating lymphocytes and reversed the immunosuppressive effect of radiation on the tumor microenvironment in mouse model. Compared with radioimmunotherapy, the addition of anlotinib also boosted the infiltration of CD8+ T cells and M1 cells and caused a decrease in the number of MDSCs and M2 cells in mice. The levels of IFN-gamma and IL-18 were the highest in the triple therapy group, while the levels of IL-23, IL-13, IL-1 beta, IL-2, IL-6, IL-10, and Arg-1 were significantly reduced. NF-κB, MAPK, and AKT pathways were downregulated in triple therapy compared with radioimmunotherapy. Thus, the tumor immune microenvironment was significantly improved. As a consequence, triple therapy displayed greater benefit in antitumor efficacy. Conclusion Our findings indicate that anlotinib might be a potential synergistic treatment for radioimmunotherapy to achieve better antitumor efficacy in NSCLC patients by potentiating the tumor immune microenvironment.

Network Pharmacology and Experimental Verification to Explore the Potential Mechanism of Yin-Huo-Tang for Lung Adenocarcinoma Recurrence.

PurposeYin-Huo-Tang (YHT) is a classic traditional Chinese prescription, used to prevent lung adenocarcinoma (LUAD) relapse by “nourishing yin and clearing heat”. In this study, the mechanism of YHT in LUAD recurrence was investigated.MethodsFirstly, the bioactive compounds and targets of YHT, as well as related targets of LUAD recurrence, were collected from public databases. The protein–protein interaction network, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses were performed to find the pivotal compounds, hub genes, functional annotation and main pathways. Subsequently, RNA sequencing of recurrent tumor tissues from Lewis lung carcinoma mice treated with YHT was used to explore the main pathways. At the same time, pathways screened by network pharmacology and RNA sequencing analysis were considered the most important pathways. Finally, liquid chromatography mass spectrometry was used to validate the pivotal active ingredients. Molecular docking technology was performed to validate the binding association between the hub genes and the pivotal active ingredients. PCR and WB analysis were used to validate the main pathways.ResultsThere were 128 active compounds and 419 targets interacting with YHT and LUAD recurrence. Network analysis identified 4 pivotal compounds, 28 hub genes and 30 main pathways. Sphingolipid signaling pathway was the common main pathway in network pharmacology and RNA sequencing results. The hub gene related to the sphingolipid signaling pathway was S1PR5. Qualitative phytochemical analysis confirmed the presence of 3 pivotal compounds, namely stigmasterol, nootkatone and ergotamine. The molecular docking verified that the pivotal compounds could good affinity with S1PR5. The PCR and WB analysis verified YHT suppressed Lewis lung cancer cells proliferation and migration by inhibiting the sphingolipid signaling pathway.ConclusionThe potential mechanism and therapeutic effect of YHT against the recurrence of LUAD may be ascribed to inhibition of the sphingolipid signaling pathway.

Dihydroartemisinin inhibits Lewis Lung carcinoma progression by inducing macrophages M1 polarization via AKT/mTOR pathway

Preclinical and clinical data show a close relationship between high infiltration of tumor-associated macrophages (TAMs) and a poor prognosis in most types of tumors, thus targeting TAMs stands out as promising anticancer immunotherapies. Recent studies have demonstrated the anti-tumor effects of artemisinin via enhancing anti-tumor immunity within tumor microenvironment, but the underlying mechanism is still not clear. In the present study we uncovered an important role of dihydroartemisinin (DHA) in regulating intratumoral TAM polarization and anti-tumor immune responses in mouse Lewis Lung carcinoma model. We found that DHA inhibited Lewis Lung carcinoma progress, moderately decreased the frequencies of TAMs within tumor stroma, and significantly increased CD86 expression while decreased CD206 expression on TAMs which indicates the role of DHA in polarizing TAMs into a M1-like phenotype. Then, our in vitro data confirmed that DHA dose-dependently promoted macrophage M1 phenotype transition by increasing M1 phenotype-related molecules, meanwhile decreasing the expression of M2 phenotype-related molecules. In addition, DHA increased proinflammatory cytokine production, enhanced the phagocytic capacity while decreased anti-inflammatory cytokine production. Finally, in order to prove that AKT/mTOR signaling potentially mediated DHA-induced macrophage differentiation, we used rapamycin to specifically block the activity of mTOR and stimulated macrophages under M1 stimuli. Our data clearly showed that rapamycin significantly decreased DHA-induced M1-related phenotypes and proinflammatory cytokine expression. In summary, our study highlighted DHA as one of future potential therapeutic options for the development of novel anticancer immunotherapies in lung cancer.

Design and evaluation of folate-modified liposomes for pulmonary administration in lung cancer therapy

Pulmonary drug administration for the treatment of lung cancer is useful because the drug is directly delivered to the lung tissues with minimal invasiveness and higher efficiency compared to other conventional methods. However, it is critical to enhance drug accumulation in the lung cancer tissues to achieve sufficient therapeutic efficacy. The submicron-sized liposome (ssLip) preparation is one of the most promising approaches to enhance drug accumulation in the lungs; however, ssLips prepared for conventional inhalation do not have tumour selectivity. Therefore, in this study, we prepared folate (FA)-modified ssLip (FA-ssLip) to enhance drug accumulation in folate receptor (FR)-expressing lung cancer cells, and evaluated its physicochemical properties and potential as a drug carrier in pulmonary administration. In addition, we prepared rapamycin (RM-an autophagy-inducing anticancer drug)-loaded FA-ssLip (RM/FA-ssLip) and investigated its anti-tumour effect. FA-ssLip showed excellent nanoparticle properties with submicron size (approximately 120 nm) and high lung accumulation in lung cancer mouse model-bearing LL2 cells—a mouse Lewis lung carcinoma cell line. RM/FA-ssLip showed significant cytotoxic activity in FR-expressing cancer cells. In addition, pulmonary administration of RM/FA-ssLip extended the survival of LL2 cell tumour-bearing mice. Taken together, our results suggest the potential of FA-ssLip as a pulmonary drug carrier for the efficient treatment of lung cancer.

USP5 facilitates non-small cell lung cancer progression through stabilization of PD-L1

PD-L1(CD274) is a well-known immunosuppressive molecule, which confers immunoescape features to cancer cells and has become one of the major targets in cancer immunotherapies. Understanding the regulatory mechanisms that control PD-L1 protein expression is important for guiding immune checkpoint blockade therapy. Here, we showed that ubiquitin specific peptidase 5 (USP5) was a novel PD-L1 deubiquitinase in non-small cell lung cancer (NSCLC) cells. USP5 directly interacted with PD-L1 and deubiquitinated PD-L1, therefore enhances PD-L1 protein stability. Meanwhile, USP5 protein levels were highly elevated and positively correlated to PD-L1 levels in NSCLC tissues, and were closely correlated with poor prognosis of these patients. In addition, knockdown of USP5 retarded tumor growth in the Lewis lung carcinoma mouse model. Thus, we identified that USP5 was a new regulator of PD-L1 and targeting USP5 is a promising strategy for cancer therapy.

Activin-A impedes the establishment of CD4+ T cell exhaustion and enhances anti-tumor immunity in the lung

BackgroundAlthough tumor-infiltrating T cells represent a favorable prognostic marker for cancer patients, the majority of these cells are rendered with an exhausted phenotype. Hence, there is an unmet need to identify factors which can reverse this dysfunctional profile and restore their anti-tumorigenic potential. Activin-A is a pleiotropic cytokine, exerting a broad range of pro- or anti-inflammatory functions in different disease contexts, including allergic and autoimmune disorders and cancer. Given that activin-A exhibits a profound effect on CD4+ T cells in the airways and is elevated in lung cancer patients, we hypothesized that activin-A can effectively regulate anti-tumor immunity in lung cancer.MethodsTo evaluate the effects of activin-A in the context of lung cancer, we utilized the OVA-expressing Lewis Lung Carcinoma mouse model as well as the B16F10 melanoma model of pulmonary metastases. The therapeutic potential of activin-A-treated lung tumor-infiltrating CD4+ T cells was evaluated in adoptive transfer experiments, using CD4−/−-tumor bearing mice as recipients. In a reverse approach, we disrupted activin-A signaling on CD4+ T cells using an inducible model of CD4+ T cell-specific knockout of activin-A type I receptor. RNA-Sequencing analysis was performed to assess the transcriptional signature of these cells and the molecular mechanisms which mediate activin-A’s function. In a translational approach, we validated activin-A’s anti-tumorigenic properties using primary human tumor-infiltrating CD4+ T cells from lung cancer patients.ResultsAdministration of activin-A in lung tumor-bearing mice attenuated disease progression, an effect associated with heightened ratio of infiltrating effector to regulatory CD4+ T cells. Therapeutic transfer of lung tumor-infiltrating activin-A-treated CD4+ T cells, delayed tumor progression in CD4−/− recipients and enhanced T cell-mediated immunity. CD4+ T cells genetically unresponsive to activin-A, failed to elicit effective anti-tumor properties and displayed an exhausted molecular signature governed by the transcription factors Tox and Tox2. Of translational importance, treatment of activin-A on tumor-infiltrating CD4+ T cells from lung cancer patients augmented their immunostimulatory capacity towards autologous CD4+ and CD8+ T cells.ConclusionsIn this study, we introduce activin-A as a novel immunomodulatory factor in the lung tumor microenvironment, which bestows exhausted CD4+ T cells with effector properties.

FGF9/FGFR1 promotes cell proliferation, epithelial-mesenchymal transition, M2 macrophage infiltration and liver metastasis of lung cancer

Fibroblast growth factors 9 (FGF9) modulates cell proliferation, differentiation and motility for development and repair in normal cells. Abnormal activation of FGF9 signaling is associated with tumor progression in many cancers. Also, FGF9 may be an unfavorable prognostic indicator for non-small cell lung cancer patients. However, the effects and mechanisms of FGF9 in lung cancer remain elusive. In this study, we investigated the FGF9-induced effects and signal activation profiles in mouse Lewis lung carcinoma (LLC) in vitro and in vivo. Our results demonstrated that FGF9 significantly induced cell proliferation and epithelial-to-mesenchymal transition (EMT) phenomena (migration and invasion) in LLC cells. Mechanism-wise, FGF9 interacted with FGFR1 and activated FAK, AKT, and ERK/MAPK signal pathways, induced the expression of EMT key proteins (N-cadherin, vimentin, snail, MMP2, MMP3 and MMP13), and reduced the expression of E-cadherin. Moreover, in the allograft mouse model, intratumor injection of FGF9 to LLC-tumor bearing C57BL/6 mice enhanced LLC tumor growth which were the results of increased Ki67 expression and decreased cleaved caspase-3 expression compared to control groups. Furthermore, we have a novel finding that FGF9 promoted liver metastasis of subcutaneous inoculated LLC tumor with angiogenesis, EMT and M2-macrophage infiltration in the tumor microenvironment. In conclusion, FGF9 activated FAK, AKT, and ERK signaling through FGFR1 with induction of EMT to stimulate LLC tumorigenesis and hepatic metastasis. This novel FGF9/LLC allograft animal model may therefore be useful to study the mechanism of liver metastasis which is the worst prognostic factor for lung cancer patients with distant organ metastasis.

N6-methyladenosine-modified circIGF2BP3 inhibits CD8+ T-cell responses to facilitate tumor immune evasion by promoting the deubiquitination of PD-L1 in non-small cell lung cancer

BackgroundAn in-depth understanding of immune evasion mechanisms in tumors is crucial to overcome resistance and enable innovative advances in immunotherapy. Circular RNAs (circRNAs) have been implicated in cancer progression. However, much remains unknown regarding whether circRNAs impact immune escape in non-small-cell lung carcinoma (NSCLC).MethodsWe performed bioinformatics analysis to profile and identify the circRNAs mediating immune evasion in NSCLC. A luciferase reporter assay, RNA immunoprecipitation (RIP), RNA pulldown assays and fluorescence in situ hybridization were performed to identify the interactions among circIGF2BP3, miR-328-3p, miR-3173-5p and plakophilin 3 (PKP3). In vitro T cell-mediated killing assays and in vivo syngeneic mouse models were used to investigate the functional roles of circIGF2BP3 and its downstream target PKP3 in antitumor immunity in NSCLC. The molecular mechanism of PKP3-induced PD-L1 upregulation was explored by immunoprecipitation, RIP, and ubiquitination assays.ResultsWe demonstrated that circIGF2BP3 (hsa_circ_0079587) expression was increased in NSCLC and negatively correlated with CD8+ T cell infiltration. Functionally, elevated circIGF2BP3 inactivated cocultured T cells in vitro and compromised antitumor immunity in an immunocompetent mouse model, and this effect was dependent on CD8+ T cells. Mechanistically, METTL3 mediates the N6-methyladenosine (m6A) modification of circIGF2BP3 and promotes its circularization in a manner dependent on the m6A reader protein YTHDC1. circIGF2BP3 competitively upregulates PKP3 expression by sponging miR-328-3p and miR-3173-5p to compromise the cancer immune response. Furthermore, PKP3 engages with the RNA-binding protein FXR1 to stabilize OTUB1 mRNA, and OTUB1 elevates PD-L1 abundance by facilitating its deubiquitination. Tumor PD-L1 deletion completely blocked the impact of the circIGF2BP3/PKP3 axis on the CD8+ T cell response. The inhibition of circIGF2BP3/PKP3 enhanced the treatment efficacy of anti-PD-1 therapy in a Lewis lung carcinoma mouse model. Collectively, the PKP3/PD-L1 signature and the infiltrating CD8+ T cell status stratified NSCLC patients into different risk groups.ConclusionOur results reveal the function of circIGF2BP3 in causing immune escape from CD8+ T cell-mediated killing through a decrease in PD-L1 ubiquitination and subsequent proteasomal degradation by stabilizing OTUB1 mRNA in a PKP3-dependent manner. This work sheds light on a novel mechanism of PD-L1 regulation in NSCLC and provides a rationale to enhance the efficacy of anti-PD-1 treatment in NSCLC.