Tumor necrosis factor-α-dependent inflammation upregulates high mobility group box 1 to induce tumor promotion and anti-programmed cell death protein-1 immunotherapy resistance in lung adenocarcinoma.

Tumor-associated chronic lung inflammation depends on tumor necrosis factor (TNF)-α to activate several cytokines as part of an inflammatory loop, which plays a critical role in tumor progression in lung adenocarcinoma. High mobility group box 1 (HMGB1) is a cytokine that mediates inflammation. Whether TNF-α-induced inflammation regulates HMGB1 to contribute to tumor progression and promotion in lung adenocarcinoma remains unclear. Thus, human samples and a urethane-induced inflammation-driven lung adenocarcinoma (IDLA) mouse model were used to explore the involvement of HMGB1 in tumorigenesis, tumor progression, and efficacy of anti-programmed cell death protein (PD)-1 immunotherapy. High levels of HMGB1 were observed in human lung adenocarcinoma associated with poor overall survival in patients. HMGB1 upregulation was positively correlated with TNF-α-related inflammation and TIM3+ infiltration. TNF-α upregulated intracellular and extracellular HMGB1 expression to contribute to tumor promotion in A549 cells in vitro. Using a urethane-induced IDLA mouse model, we found HMGB1 upregulation was associated with increased TIM3+ T cell infiltration. Blocking TNF-α-dependent inflammation downregulated HMGB1 expression and inhibited tumorigenesis in the IDLA. Anti-PD-1 treatment alone did not inhibit tumor growth in the TNF-α-dependent IDLA, whereas anti-PD-1 combined with TNF-α blockade overcame anti-PD-1 immunotherapy resistance. Furthermore, anti-PD-1 combined with anti-HMGB1 also inhibited tumor growth in IDLA, suggesting increased HMGB1 release by TNF-α contributes to the resistance of anti-PD-1 immunotherapy in IDLA. Thus, tumor-associated TNF-α-dependent inflammation upregulated intracellular and extracellular HMGB1 expression in an inflammatory loop, contributing to tumor promotion and anti-PD-1 immunotherapy resistance in lung adenocarcinoma.

Tumor Necrosis Factor α-Dependent Lung Inflammation Promotes the Progression of Lung Adenocarcinoma Originating From Alveolar Type II Cells by Upregulating MIF-CD74.

Lung adenocarcinoma is the most common type of lung cancer. We recently reported that inflammation-driven lung adenocarcinoma (IDLA) originates from alveolar type (AT)-II cells, which depend on major histocompatibility complex (MHC) class II to promote the expansion of regulatory T cells. The MHC class II-associated invariant chain (CD74) binds to the macrophage migration inhibitory factor (MIF), which is associated with promoting tumor growth and invasion. However, the role of MIF-CD74 in the progression of lung adenocarcinoma and the underlying mechanisms remain unclear. We aimed to explore the role of MIF-CD74 in the progression of lung adenocarcinoma and elucidate the mechanisms by which tumor necrosis (TNF)-α-mediated inflammation regulates CD74 and MIF expression in IDLA. In human lung adenocarcinoma, CD74 was upregulated on the surface of tumor cells originating from AT-II cells, which correlated positively with lymph node metastasis, tumor origin/nodal involvement/metastasis stage, and TNF-α expression. MIF interaction with CD74 promoted the proliferation and migration of A549 and H1299 cells in vitro. Using a urethane-induced IDLA mouse model, we observed that CD74 was upregulated in tumor cells and macrophages. MIF expression was upregulated in macrophages in IDLA. Blocking TNF-α-dependent inflammation downregulated CD74 expression in tumor cells and CD74 and MIF expression in macrophages in IDLA. Conditioned medium from A549 cells or activated mouse AT-II cells upregulated MIF in macrophages by secreting TNF-α. TNF-α-dependent lung inflammation contributes to the progression of lung adenocarcinoma by upregulating CD74 and MIF expression, and AT-II cells upregulate MIF expression in macrophages by secreting TNF-α. This study provides novel insights into the function of CD74 in the progression of IDLA.

TNF-α-dependent lung inflammation upregulates PD-L1 in monocyte-derived macrophages to contribute to lung tumorigenesis.

Chronic inflammation, which is dominated by macrophage-involved inflammatory responses, is an instigator of cancer initiation. Macrophages are the most abundant immune cells in healthy lungs, and associated with lung tumor development and promotion. PD-L1 is a negative molecule in macrophages and correlated with an immunosuppressive function in tumor environment. Macrophages expressing PD-L1, rather than tumor cells, exhibits a critical role in tumor growth and progression. However, whether and how PD-L1 in macrophages contributes to inflammation-induced lung tumorigenesis requires further elucidation. Here, we found that higher expression of PD-L1 in CD11b+ CD206+ macrophages was positively correlated with tumor progression and PD-1+ CD8+ T cells population in human adenocarcinoma patients. In the urethane-induced inflammation-driven lung adenocarcinoma (IDLA) mouse model, the infiltration of circulating CD11bhigh F4/80+ monocyte-derived macrophages (MoMs) was increased in pro-tumor inflamed lung tissues and lung adenocarcinoma. PD-L1 was mainly upregulated in MoMs associated with enhanced T cells exhaustion in lung tissues. Anti-PD-L1 treatment can reduce T cells exhaustion at pro-tumor inflammatory stage, and then inhibit tumorigenesis in IDLA. The pro-tumor lung inflammation depended on TNF-α to upregulate PD-L1 and CSN6 expression in MoMs, and induced cytokines production by alveolar type-II cells (AT-II). Furthermore, inflammatory AT-II cells could secret TNF-α to upregulate PD-L1 expression in bone-marrow driven macrophages (BM-M0). Inhibition of CSN6 decreased PD-L1 expression in TNF-α-activated macrophage in vitro, suggesting a critical role of CSN6 in PD-L1 upregulation. Thus, pro-tumor inflammation can depend on TNF-α to upregulate PD-L1 in recruited MoMs, which may be essential for lung tumorigenesis.

Lung adenocarcinoma-related TNF-α-dependent inflammation upregulates MHC-II on alveolar type II cells through CXCR-2 to contribute to Treg expansion.

MHC-II on alveolar type-II (AT-II) cells is associated with immune tolerance in an inflammatory microenvironment. Recently, we found TNF-α upregulated MHC-II in AT-II in vitro. In this study, we explored whether TNF-α-mediated inflammation upregulates MHC-II on AT-II cells to trigger Treg expansion in inflammation-driven lung adenocarcinoma (IDLA). Using urethane-induced mice IDLA model, we found that IDLA cells mainly arise from AT-II cells, which are the major source of MHC-II. Blocking urethane-induced inflammation by TNF-α neutralization inhibited tumorigenesis and reversed MHC-II upregulation on tumor cells of AT-II cellular origin in IDLA. MHC-II-dependent AT-II cells were isolated from IDLA-induced Treg expansion. In human LA samples, we found high expression of MHC-II in tumor cells of AT-II cellular origin, which was correlated with increased Foxp3+ T cells infiltration as well as CXCR-2 expression. CXCR-2 and MHC-II colocalization was observed in inflamed lung tissue and IDLA cells of AT-II cellular origin. Furthermore, at the pro-IDLA inflammatory stage, TNF-α-neutralization or CXCR-2 deficiency inhibited the upregulation of MHC-II on AT-II cells in inflamed lung tissue. Thus, tumor cells of AT-II cellular origin contribute to Treg expansion in an MHC-II-dependent manner in TNF-α-mediated IDLA. At the pro-tumor inflammatory stage, TNF-α-dependent lung inflammation plays an important role in MHC-II upregulation on AT-II cells.

Aflatoxin G1 induced TNF-α-dependent lung inflammation to enhance DNA damage in alveolar epithelial cells.

Aflatoxin G1 (AFG1 ), a member of the AF family with cytotoxic and carcinogenic properties, could cause DNA damage in alveolar type II (AT-II) cells and induce lung adenocarcinoma. Recently, we found AFG1 could induce chronic lung inflammation associated with oxidative stress in the protumor stage. Chronic inflammation plays a critical role in cigarette smoke or benzo[a]pyrene-induced lung tissues damage. However, it is unclear whether and how AFG1 -induced lung inflammation affects DNA damage in AT-II cells. In this study, we found increased DNA damage and cytochrome P450 (CYP2A13) expression in AFG1 -induced inflamed lung tissues. Furthermore, we treated the mice with a soluble tumor necrosis factor (TNF)-α receptor and AFG1 and found that TNF-α neutralization inhibited the AFG1 -induced chronic lung inflammation in vivo, and then reversed the CYP2A13 expression and DNA damage in AT-II cells. The results suggest that AFG1 induces TNF-α-dependent lung inflammation to regulate 2A13 expression and enhance DNA damage in AT-II cells. Then, we treated the primary mice AT-II cells and human AT-II like cells (A549) with AFG1 and TNF-α and found that TNF-α enhanced the AFG1 -induced DNA damage in mice AT-II cells as well as A549 cells in vitro. In AFG1 -exposed A549 cells, TNF-α-enhanced DNA damage and apoptosis were reversed by CYP2A13 small interfering RNA. Blocking NF-κB pathway inhibited the TNF-α-enhanced CYP2A13 upregulation and DNA damage confirming that the CYP2A13 upregulation by TNF-α plays an essential role in the activation of AFG1 under inflammatory conditions. Taken together, our findings suggest that AFG1 induces TNF-α-dependent lung inflammation, which upregulates CYP2A13 to promote the metabolic activation of AFG1 and enhance oxidative DNA damage in AT-II cells.

SOX-1 antibodies positive Lambert-Eaton myasthenic syndrome with occult small cell lung cancer: A case report.

Lambert-Eaton myasthenic syndrome (LEMS) is a rare paraneoplastic neurological syndrome of the neuromuscular transmission. The symptoms often progress slowly and can be misdiagnosed in early stage. Seropositive SOX-1 antibodies are support for the diagnosis of LEMS and have high specificity for small cell lung cancer (SCLC). In this paper, we report a case of a 56-year-old man with smoking history who was admitted to hospital with progressive muscle weakness of the proximal legs. LEMS was diagnosed by repetitive nerve stimulation (RNS) testing and seropositive SOX-1 antibodies. Primary screening with chest computed tomography (CT) and integrated PET/CT did not reveal any tumor. After continuous follow-up, SCLC was found by chest CT and confirmed with pathological examination 10 months after the diagnosis of LEMS. Long-term follow-up and screening for occult SCLC in LEMS patients with positive SOX-1 antibodies are very important.

High mobility group box-1 protects against Aflatoxin G1-induced pulmonary epithelial cell damage in the lung inflammatory environment.

Aflatoxin G1 (AFG1) is a member of the carcinogenic aflatoxin family. Our previous studies indicated that oral administration of AFG1 caused tumor necrosis factor (TNF)-α-dependent inflammation that enhanced oxidative DNA damage in alveolar epithelial cells, which may be related to AFG1-induced lung carcinogenesis. High mobility group box-1 (HMGB1) is a nuclear DNA-binding protein; the intracellular and extracellular roles of HMGB1 have been shown to contribute to DNA repair and sterile inflammation. The role of HMGB1 in DNA damage in an aflatoxin-induced lung inflammatory environment was investigated in this study. Upregulation of HMGB1, TLR2, and RAGE was observed in AFG1-induced lung inflamed tissues and adenocarcinoma. Blocking AFG1-induced inflammation by neutralization of TNF-α inhibited the upregulation of HMGB1 in mouse lung tissues, suggesting that AFG1-induced TNF-α-dependent inflammation regulated HMGB1 expression. In the in vitro human pulmonary epithelial cell line model, Beas-2b, AFG1 directly enhanced the cytosolic translocation of HMGB1 and its extracellular secretion. The addition of extracellular soluble HMGB1 protected AFG1-induced DNA damage through the TLR2/NF-κB pathway in Beas-2b cells. In addition, blockade of endogenous HMGB1 by siRNA significantly enhanced AFG1-induced damage. Thus, our findings showed that both extracellularly-released and nuclear and cytosolic HMGB1 could protect the cell from AFG1-induced cell damage in a TNF-α-dependent lung inflammatory environment.

[Relationship between EGFR Mutations and Pathological Classification and 
Specimen of Lung Adenocarcinoma].

BACKGROUND: With the development of genetic mutations and targeted drugs, accurate therapy of lung adenocarcinoma attracts much more attention, and more research is focued on epidermal growth factor receptor (EGFR). It is unclear whether the result of EGFR mutation and pathology type is consistent with different specimens. In our study, by comparing the relationship between EGFR mutations and pathological classification of lung adenocarcinoma in surgical resection of specimen and biopsy specimen, to discuss the relationship between EGFR mutations and pathological classification of and the influence of specimen type on EGFR gene detection. METHODS: A total of 163 cases of surgical resection of sample of lung adenocarcinoma (pulmonary resection and pulmonary lobectomy) and 173 cases of biopsy specimen [mucosa biopsy, needle biopsy of lung, and endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA)] were performed by gene sequencing method and amplification refractory mutation system (ARMS) and the majority of the type was confirmed (lepidic, acinar, papillary, micropapillary, solid) according to the classification of lung adenocarcinoma in 2015 World Health Organization (WHO). The statistics was used in surgical and biopsy sample respectively. RESULTS: The gene mutation of EGFR in surgical and biopsy sample of lung adenocarcinoma was 62.58% (102/163) and 65.9% (114/173) respectively, and no significant difference was found (P>0.05). The mutation of EGFR in female was predominant both of the two groups (P<0.05). The mutation rate of EGFR over the age of 60 was significantly lower than that below 60 in surgical specimen, while it was not related to age in biopsy sample. The constituent ratio of pathology type was different in the two groups (χ2=8.04, P<0.05). Among 102 cases of lung adenocarcinoma in surgical specimen, the acinar took up the highest proportion (54.9%), followed by the lepidic (23.53%) and the papillary (17.65%). The solid adenocarcinoma accounted for the minimal percentage (3.9%). The mutation of 19 and 21 exon alone was most common. The mutation rate of 21 exon in the lepidic was higher than that in the acinar and papillary (P<0.05), but the mutation rate of 19 exon in the papillary was higher than that in the lepidic (P<0.05). There was no significant difference of 19 and 21 exon in the acinar and papillary. Among 114 cases of lung adenocarcinoma in the biopsy specimen, the most percentage was the acinar (48.25%), the lepidic was secondly, and the papillary, micropapillary and solid adenocarcinoma was the minimal. The exon mutation of 19 and 21 exon alone was most common, while no obvious difference of 19 and 21 exon was found in different pathology classifications (P>0.05). CONCLUSIONS: The mutation rate of EGFR of lung adenocarcinoma in surgical resected specimen and biopsy specimen was not found difference, which was related to sex, and the female was predominant. The mutation rate of surgical specimen was higher in the young, while that of biopsy specimen was not related to the age. Apparent difference of the pathology type proportion was found in the two groups. The mutation of 19 and 21 exon alone was most common. The mutation of EGFR in surgical specimens was related to pathology types. The percentage of the lepidic adenocarcinoma was highest in the mutation of 21 exon alone. Among the mutation of 19 exon alone, the papillary was predominant. There was no obvious relationship between the mutation of 19 and 21 exon alone and pathology type in biopsy sample.

Inflammation-mediated SOD-2 upregulation contributes to epithelial-mesenchymal transition and migration of tumor cells in aflatoxin G1-induced lung adenocarcinoma.

Tumor-associated inflammation plays a critical role in facilitating tumor growth, invasion and metastasis. Our previous study showed Aflatoxin G1 (AFG1) could induce lung adenocarcinoma in mice. Chronic lung inflammation associated with superoxide dismutase (SOD)-2 upregulation was found in the lung carcinogenesis. However, it is unclear whether tumor-associated inflammation mediates SOD-2 to contribute to cell invasion in AFG1-induced lung adenocarcinoma. Here, we found increased SOD-2 expression associated with vimentin, α-SMA, Twist1, and MMP upregulation in AFG1-induced lung adenocarcinoma. Tumor-associated inflammatory microenvironment was also elicited, which may be related to SOD-2 upregulation and EMT in cancer cells. To mimic an AFG1-induced tumor-associated inflammatory microenvironment in vitro, we treated A549 cells and human macrophage THP-1 (MΦ-THP-1) cells with AFG1, TNF-α and/or IL-6 respectively. We found AFG1 did not promote SOD-2 expression and EMT in cancer cells, but enhanced TNF-α and SOD-2 expression in MΦ-THP-1 cells. Furthermore, TNF-α could upregulate SOD-2 expression in A549 cells through NF-κB pathway. Blocking of SOD-2 by siRNA partly inhibited TNF-α-mediated E-cadherin and vimentin alteration, and reversed EMT and cell migration in A549 cells. Thus, we suggest that tumor-associated inflammation mediates SOD-2 upregulation through NF-κB pathway, which may contribute to EMT and cell migration in AFG1-induced lung adenocarcinoma.