SRGN-Triggered Aggressive and Immunosuppressive Phenotype in a Subset of TTF-1-Negative Lung Adenocarcinomas

The relationship between tumor immunity and the cGAS-STING pathway in breast cancer: An immunohistochemical study

Breast cancer (BC) is classified into four major histological subtypes, namely luminal A, luminal B, HER2, and basal-like, and its treatment is based on these subtypes. The use of immune checkpoint inhibitors against BC depends on the expression of PD-1/PD-L1. Another tumor immune system-the cGAS-STING pathway-is a potential target for cancer immunotherapy. However, the status of the cGAS-STING pathway in BC has not been fully established. Therefore, we investigated the expression status of the cGAS-STING pathway and immune-related proteins in BC. We classified 111 BCs into six groups-29 hormone receptor-positive carcinomas, 12 HER2+ carcinomas (HER2), 8 luminal-HER2 carcinomas, 26 triple-negative breast carcinomas (TNBCs), 21 lobular carcinomas (LC), and 15 carcinomas with apocrine differentiation (CAD)-and investigated the relationship between BC and tumor immunity via the cGAS-STING pathway using histopathological and immunohistochemical methods. Expression of cGAS was high in CADs (100%) and low in TNBCs (35%); STING-positive lymphocytes were high in TNBC (85%, P = 0.0054). Expression of pSTAT3 was significantly high in patients with TNBC (≥10%, 88%). The proportion of PD-L1-positive tumor cells was higher in TNBCs (54%) than in other BCs (30%). SRGN expression was significantly higher in the TNBC group than in the other BC groups (58%). Tumor immune responses may differ among tumor subtypes. The cGAS-STING pathway may be functional in TNBC and CAD but not in LC. Therefore, targeting the cGAS-STING pathway might be useful in BC, particularly TNBC and CAD.

Tumour cell-derived serglycin promotes IL-8 secretion of CAFs in gastric cancer

BACKGROUND

Cancer-associated fibroblasts (CAFs)-derived IL-8 plays important roles in chemoresistance, immunosuppression, and lymph node metastasis of gastric cancer. However, the mechanisms underlying IL-8 production in CAFs remains unclear.

METHODS

DNA pulldown assay was performed to identify the transcription factors responsible for IL-8 expression in CAFs, which was further verified using CHIP-qPCR and DNA agarose gel electrophoresis assays. The cellular localisation of IL-8 was analysed using multiplex immunofluorescence (MxIF).

RESULTS

MxIF demonstrated that IL-8 was mainly produced by CAFs in gastric cancer. Lysine[K]-specific demethylase 5B (KDM5B) was identified as an IL-8 transcription factor in CAFs, and the binding of KDM5B to phosphorylated RB1 limited the transcriptional regulation of IL-8 in gastric cancer cells. Serglycin (SRGN) secreted by tumour cells activated the CD44/c-Myc pathway to upregulate KDM5B expression, thereby promoting IL-8 production in CAFs. Furthermore, tumour-associated neutrophils (TANs)-derived regenerating family member 4 (REG4) upregulates SRGN expression by activating cAMP-responsive element binding protein 1 (CREB1) in gastric cancer cells. Thus, the SRGN-IL-8-TANs-SRGN loop, which facilitates tumour progression, has been explored in gastric cancer.

CONCLUSIONS

This study revealed the mechanisms of the preferential production of IL-8 by CAFs in gastric cancer, and paves the way for potential new therapeutic strategies for gastric cancer.

SRGN amplifies microglia-mediated neuroinflammation and exacerbates ischemic brain injury

BACKGROUND

Microglia is the major contributor of post-stroke neuroinflammation cascade and the crucial cellular target for the treatment of ischemic stroke. Currently, the endogenous mechanism underlying microglial activation following ischemic stroke remains elusive. Serglycin (SRGN) is a proteoglycan expressed in immune cells. Up to now, the role of SRGN on microglial activation and ischemic stroke is largely unexplored.

METHODS

Srgn knockout (KO), Cd44-KO and wild-type (WT) mice were subjected to middle cerebral artery occlusion (MCAO) to mimic ischemic stroke. Exogenous SRGN supplementation was achieved by stereotactic injection of recombinant mouse SRGN (rSRGN). Cerebral infarction was measured by 2,3,5-triphenyltetrazolium chloride (TTC) staining. Neurological functions were evaluated by the modified neurological severity score (mNSS) and grip strength. Microglial activation was detected by Iba1 immunostaining, morphological analysis and cytokines' production. Neuronal death was examined by MAP2 immunostaining and FJB staining.

RESULTS

The expression of SRGN and its receptor CD44 was significantly elevated in the ischemic mouse brains, especially in microglia. In addition, lipopolysaccharide (LPS) induced SRGN upregulation in microglia in vitro. rSRGN worsened ischemic brain injury in mice and amplified post-stroke neuroinflammation, while gene knockout of Srgn exerted reverse impacts. rSRGN promoted microglial proinflammatory activation both in vivo and in vitro, whereas Srgn-deficiency alleviated microglia-mediated inflammatory response. Moreover, the genetic deletion of Cd44 partially rescued rSRGN-induced excessed neuroinflammation and ischemic brain injury in mice. Mechanistically, SRGN boosted the activation of NF-κB signal, and increased glycolysis in microglia.

CONCLUSION

SRGN acts as a novel therapeutic target in microglia-boosted proinflammatory response following ischemic stroke.

Heterogeneity in PD-L1 expression in MAML2-rearranged mucoepidermoid carcinoma

OBJECTIVE

Mucoepidermoid carcinoma (MEC) is a malignant tumor with diverse morphologies, some of which have poor prognostic indicators and others that challenge the grading system. This study investigated the expression of PD-L1 in different grades and phenotypes of MEC.

METHODS

The present study was carried out on twenty-four archival formalin-fixed, paraffin-embedded blocks of salivary MEC. Fluorescence in situ hybridization was used to detect MAML2 rearrangement in MEC cases to be included. The studied cases were then subcategorized based on their grading and phenotype and immunohistochemically stained for PD-L1.

RESULTS

PD-L1 expression in MEC varied, with some variants showing moderate to strong immunoexpression, while others did not express it at all. In the Warthin-like MEC, some tumors show high expression of PD-L1, while in the same pattern, a few cases showed low or no expression. Intraosseous MEC exhibited moderate PD-L1 expression. Sclerosing MEC featured lower PD-L1 expression, from weak to moderate. Oncocytic MEC displayed relatively low PD-L1 expression levels (weak to moderate).

CONCLUSION

The histomorphologic features of MEC may predict clinicopathologic behavior, and subtyping MEC may pose a significant therapeutic value, particularly for intraosseous MECs and clear-cell MECs. PD-L1 expression is a good predictor of survival outcomes in MECs.

Thyroid transcription factor 1 (TTF-1) negativity as a predictor of unfavorable response to EGFR-TKI therapy in advanced lung adenocarcinoma patients with EGFR mutations

BACKGROUND

The absence of thyroid transcription factor 1 (TTF-1) is associated with a lower frequency of epidermal growth factor receptor (EGFR) mutations in lung adenocarcinoma (LUAD). The aim of this study was to assess the impact of TTF-1 expression on the clinical response to EGFR-tyrosine kinase inhibitor (TKI) treatment in patients with advanced LUAD.

METHODS

The data of patients with advanced LUAD who were admitted to the Beijing Tiantan Hospital and Peking University Cancer Hospital (China) between April 2009 and May 2023 was retrospectively analyzed.

RESULTS

A total of 227 patients diagnosed with advanced LUAD were included, of which 28.2% (64/227) had TTF-1-negative adenocarcinoma, while 54.6% (124/227) harbored EGFR mutations. Negative TTF-1 expression significantly correlated with male sex (68.8% vs. 42.3%, p < 0.001), history of heavy smoking (57.8% vs. 36.2%, p = 0.003), poorly differentiated tumors (86.5% vs. 43.2%, p < 0.001), and lower frequency of EGFR mutations (26.6% vs. 65.6%, p < 0.001) compared with TTF-1 positivity. Multivariable logistic regression showed that low prevalence of EGFR mutations (p < 0.001) and male sex (p = 0.006) were independent predictive factors for the negative expression of TTF-1. Patients lacking TTF-1 also exhibited worse overall response rate (ORR; 23.5% vs. 54.2%, p = 0.019), disease control rate (DCR; 58.8% vs. 89.7%, p = 0.003), and median progression-free survival (PFS; 2.9 vs. 11.6 months, p < 0.001) following treatment with EGFR-TKIs compared to the TTF-1-positive patients with EGFR mutations.

CONCLUSIONS

Patients with TTF-1-negative and EGFR-mutant LUAD show a diminished response to EGFR-TKIs.

Thyroid transcription factor-1 (TTF-1) expression and the efficacy of combination therapy with immune checkpoint inhibitors and cytotoxic chemotherapy in non-squamous non-small cell lung cancer

Background

Thyroid transcription factor-1 (TTF-1) is expressed in approximately 70% of lung adenocarcinomas and is one of the most reliable makers to distinguish primary lung adenocarcinoma from metastatic disease. TTF-1-negative status is a poor prognostic factor, and TTF-1-negative lung adenocarcinoma is associated with poor efficacy of immune checkpoint inhibitor (ICI) monotherapy. However, the relationship between TTF-1 expression and the efficacy of ICI plus chemotherapy is still unclear.

Methods

We performed a retrospective analysis of 129 consecutive patients with advanced non-squamous non-small cell lung cancer (NS-NSCLC) treated with ICI monotherapy or ICI plus chemotherapy between January 2016 and December 2021. The expression of programmed death ligand-1 (PD-L1) and TTF-1 was also determined in cases for which no previous data were available. We then evaluated the association between TTF-1 expression status and treatment efficacy.

Results

Of the 129 cases, 33 were TTF-1-negative and 96 were positive. In the ICI monotherapy group (N=70), progression-free survival (PFS) was not significantly different between TTF-1-positive and negative patients (median 3.6 vs. 3.8 months, P=0.27); however, in patients with wild-type epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK), a trend for worse PFS was observed in TTF-1-negative cases compared with those that were TTF-1-positive (median 3.8 vs. 4.5 months, P=0.088). Moreover, long-term efficacy of ICI monotherapy (>2 years) was not observed in the TTF-1-negative group. TTF-1-negative patients tended to have worse overall survival (OS) than TTF-1-positive patients (median 15.6 vs. 19.5 months, P=0.13). In the ICI plus chemotherapy group (N=59), TTF-1-negative patients tended to have better PFS and similar OS compared with TTF-1-positive patients (median 9.9 vs. 9.6 months, P=0.14; median 32.3 vs. 18.9 months, P=0.78). Long-term efficacy was generally observed in TTF-1-negative patients treated with atezolizumab plus bevacizumab plus carboplatin plus paclitaxel (ABCP) (median PFS 22.5 months, median OS not reached).

Conclusions

ICI monotherapy is generally less efficacious in TTF-1-negative NS-NSCLC patients, and clinicians should consider ICI plus chemotherapy in these cases. Our study suggests that ABCP is an optimal regimen for TTF-1-negative NS-NSCLC.

Identification and validation of novel biomarkers associated with immune infiltration for the diagnosis of osteosarcoma based on machine learning

Objectives: Osteosarcoma is the most common primary malignant tumor in children and adolescents, and the 5-year survival of osteosarcoma patients gained no substantial improvement over the past decades. Effective biomarkers in diagnosing osteosarcoma are warranted to be developed. This study aims to explore novel biomarkers correlated with immune cell infiltration in the development and diagnosis of osteosarcoma. Methods: Three datasets (GSE19276, GSE36001, GSE126209) comprising osteosarcoma samples were extracted from Gene Expression Omnibus (GEO) database and merged to obtain the gene expression. Then, differentially expressed genes (DEGs) were identified by limma and potential biological functions and downstream pathways enrichment analysis of DEGs was performed. The machine learning algorithms LASSO regression model and SVM-RFE (support vector machine-recursive feature elimination) analysis were employed to identify candidate hub genes for diagnosing patients with osteosarcoma. Receiver operating characteristic (ROC) curves were developed to evaluate the discriminatory abilities of these candidates in both training and test sets. Furthermore, the characteristics of immune cell infiltration in osteosarcoma, and the correlations between these potential genes and immune cell abundance were illustrated using CIBERSORT. qRT-PCR and western blots were conducted to validate the expression of diagnostic candidates. Results: GEO datasets were divided into the training (merged GSE19276, GSE36001) and test (GSE126209) groups. A total of 71 DEGs were screened out in the training set, including 10 upregulated genes and 61 downregulated genes. These DEGs were primarily enriched in immune-related biological functions and signaling pathways. After machine learning by SVM-RFE and LASSO regression model, four biomarkers were chosen for the diagnostic nomogram for osteosarcoma, including ASNS, CD70, SRGN, and TRIB3. These diagnostic biomarkers all possessed high diagnostic values (AUC ranging from 0.900 to 0.955). Furthermore, these genes were significantly correlated with the infiltration of several immune cells, such as monocytes, macrophages M0, and neutrophils. Conclusion: Four immune-related candidate hub genes (ASNS, CD70, SRGN, TRIB3) with high diagnostic value were confirmed for osteosarcoma patients. These diagnostic genes were significantly connected with the immune cell abundance, suggesting their critical roles in the osteosarcoma tumor immune microenvironment. Our study provides highlights on novel diagnostic candidate genes with high accuracy for diagnosing osteosarcoma patients.

Metabolic barriers in non-small cell lung cancer with LKB1 and/or KEAP1 mutations for immunotherapeutic strategies

Currently, immune checkpoint inhibitors (ICIs) are widely considered the standard initial treatment for advanced non-small cell lung cancer (NSCLC) when there are no targetable driver oncogenic alternations. NSCLC tumors that have two alterations in tumor suppressor genes, such as liver kinase B1 (LKB1) and/or Kelch-like ECH-associated protein 1 (KEAP1), have been found to exhibit reduced responsiveness to these therapeutic strategies, as revealed by multiomics analyses identifying immunosuppressed phenotypes. Recent advancements in various biological approaches have gradually unveiled the molecular mechanisms underlying intrinsic reprogrammed metabolism in tumor cells, which contribute to the evasion of immune responses by the tumor. Notably, metabolic alterations in glycolysis and glutaminolysis have a significant impact on tumor aggressiveness and the remodeling of the tumor microenvironment. Since glucose and glutamine are essential for the proliferation and activation of effector T cells, heightened consumption of these nutrients by tumor cells results in immunosuppression and resistance to ICI therapies. This review provides a comprehensive summary of the clinical efficacies of current therapeutic strategies against NSCLC harboring LKB1 and/or KEAP1 mutations, along with the metabolic alterations in glycolysis and glutaminolysis observed in these cancer cells. Furthermore, ongoing trials targeting these metabolic alterations are discussed as potential approaches to overcome the extremely poor prognosis associated with this type of cancer.

ScRNA-seq revealed an immunosuppression state and tumor microenvironment heterogeneity related to lymph node metastasis in prostate cancer

BACKGROUND

Metastasis is a crucial aspect of disease progression leading to death in patients with prostate cancer (PCa). However, its mechanism remains unclear. We aimed to explore the mechanism of lymph node metastasis (LNM) by analyzing the heterogeneity of tumor microenvironment (TME) in PCa using scRNA-seq.

METHODS

A total of 32,766 cells were obtained from four PCa tissue samples for scRNA-seq, annotated, and grouped. InferCNV, GSVA, DEG functional enrichment analysis, trajectory analysis, intercellular network evaluation, and transcription factor analysis were carried out for each cell subgroup. Furthermore, validation experiments targeting luminal cell subgroups and CXCR4 + fibroblast subgroup were performed.

RESULTS

The results showed that only EEF2 + and FOLH1 + luminal subgroups were present in LNM, and they appeared at the initial stage of luminal cell differentiation, which were comfirmed by verification experiments. The MYC pathway was enriched in the EEF2 + and FOLH1 + luminal subgroups, and MYC was associated with PCa LNM. Moreover, MYC did not only promote the progression of PCa, but also led to immunosuppression in TME by regulating PDL1 and CD47. The proportion of CD8 + T cells in TME and among NK cells and monocytes was lower in LNM than in the primary lesion, while the opposite was true for Th and Treg cells. Furthermore, these immune cells in TME underwent transcriptional reprogramming, including CD8 + T subgroups of CCR7 + and IL7R+, as well as M2-like monocyte subgroups expressing tumor-associated signature genes, like CCR7, SGKI, and RPL31. Furthermore, STEAP4+, ADGRF5 + and CXCR4+, and SRGNC + fibroblast subgroups were closely related to tumor progression, tumor metabolism, and immunosuppression, indicating their contributions in PCa metastasis. Meanwhile, The presence of CXCR4 + Fibroblasts in PCa was confirmed by polychromatic immunofluorescence.

CONCLUSIONS

The significant heterogeneity of luminal, immune, and interstitial cells in PCa LNM may not only directly contribute to tumor progression, but also indirectly result in TME immunosuppression, which may be the cause of metastasis in PCa and in which MYC played an role.

The role of glycans in the mechanobiology of cancer

Although cancer is a genetic disease, physical changes such as stiffening of the extracellular matrix also commonly occur in cancer. Cancer cells sense and respond to extracellular matrix stiffening through the process of mechanotransduction. Cancer cell mechanotransduction can enhance cancer-promoting cell behaviors such as survival signaling, proliferation, and migration. Glycans, carbohydrate-based polymers, have recently emerged as important mediators and/or modulators of cancer cell mechanotransduction. Stiffer tumors are characterized by increased glycan content on cancer cells and their associated extracellular matrix. Here we review the role of cancer-associated glycans in coupled mechanical and biochemical alterations during cancer progression. We discuss the recent evidence on how increased expression of different glycans, in the form of glycoproteins and proteoglycans, contributes to both mechanical changes in tumors and corresponding cancer cell responses. We conclude with a summary of emerging tools that can be used to modify glycans for future studies in cancer mechanobiology.

Kynureninase Upregulation Is a Prominent Feature of NFR2-Activated Cancers and Is Associated with Tumor Immunosuppression and Poor Prognosis

The nuclear factor erythroid 2-related factor 2 (NRF2) pathway is frequently activated in various cancer types. Aberrant activation of NRF2 in cancer is attributed to gain-of-function mutations in the NRF2-encoding gene NFE2L2 or a loss of function of its suppressor, Kelch-like ECH-associated protein 1 (KEAP1). NRF2 activation exerts pro-tumoral effects in part by altering cancer cell metabolism. Previously, we reported a novel mechanism of NRF2 tumoral immune suppression through the selective upregulation of the tryptophan-metabolizing enzyme kynureninase (KYNU) in lung adenocarcinoma. In the current study, we explored the relevance of NRF2-mediated KYNU upregulation across multiple cancer types. Specifically, using a gene expression dataset for 9801 tumors representing 32 cancer types from The Cancer Genome Atlas (TCGA), we demonstrated that elevated KYNU parallels increased gene-based signatures of NRF2-activation and that elevated tumoral KYNU mRNA expression is strongly associated with an immunosuppressive tumor microenvironment, marked by high expression of gene-based signatures of Tregs as well as the immune checkpoint blockade-related genes CD274 (PDL-1), PDCD1 (PD-1), and CTLA4, regardless of the cancer type. Cox proportional hazard models further revealed that increased tumoral KYNU gene expression was prognostic for poor overall survival in several cancer types, including thymoma, acute myeloid leukemia, low-grade glioma, kidney renal papillary cell carcinoma, stomach adenocarcinoma, and pancreatic ductal adenocarcinoma (PDAC). Using PDAC as a model system, we confirmed that siRNA-mediated knockdown of NRF2 reduced KYNU mRNA expression, whereas activation of NFE2L2 (the coding gene for NRF2) through either small-molecule agonists or siRNA-mediated knockdown of KEAP1 upregulated KYNU in PDAC cells. Metabolomic analyses of the conditioned medium from PDAC cell lines revealed elevated levels of KYNU-derived anthranilate, confirming that KYNU was enzymatically functional. Collectively, our study highlights the activation of the NRF2-KYNU axis as a multi-cancer phenomenon and supports the relevance of tumoral KYNU as a marker of tumor immunosuppression and as a prognostic marker for poor overall survival.

Relationship Between TTF-1 Expression and PFS of Pemetrexed-containing Chemotherapy in Non-squamous-NSCLC Patients With and Without Driver Genes

BACKGROUND/AIM

We performed a retrospective study too clarify whether the presence or absence of driver genes affects the relationship between thyroid transcription factor-1 (TTF-1) expression and response to pemetrexed (PEM) in non-squamous non-small cell lung cancer (non-sq-NSCLC) patients.

PATIENTS AND METHODS

We reviewed the medical charts of patients treated with PEM-containing chemotherapy during the period from February 2016 to February 2022 at Mito Medical Center-University of Tsukuba, Ryugasaki Saiseikai General Hospital, and University of Tsukuba Hospital.

RESULTS

During the period of the study, 185 driver gene-negative patients negative, and 65 driver gene-positive patients were evaluated. Among the 165 driver gene-negative patients, progression free survival (PFS) of TTF-1-expressing patients treated with PEM-containing chemotherapy was significantly longer compared to that of TTF-1-negative patients. In the analysis of 65 driver gene-positive patients, the PFS of TTF-1-positive patients treated with PEM-containing chemotherapy did not differ significantly from that of TTF-1-negative patients. There was no significant difference in PFS between driver gene-negative and driver gene-positive patients treated with PEM-containing chemotherapy. Comparison between four groups defined according to the presence of driver gene and TTF-1 expression indicated shorter PFS only in 'driver gene-negative and TTF-1-negative' patients.

CONCLUSION

In driver gene-positive non-sq NSCLC patients, expression of TTF does not affect the survival outcome of PEM-containing-chemotherapy. In other words, in these patients, second-line or later-line PEM-containing chemotherapy after development of resistance for specific-tyrosine kinase inhibitor could be expected to have the same level of efficacy as first-line PEM containing chemotherapy in driver gene-negative, TTF-1-positive non-sq NSCLC patients.

A Comprehensive Search of Non-Canonical Proteins in Non-Small Cell Lung Cancer and Their Impact on the Immune Response

There is substantial interest in mining neoantigens for cancer applications. Non-canonical proteins resulting from frameshift mutations have been identified as neoantigens in cancer. We investigated the landscape of non-canonical proteins in non-small cell lung cancer (NSCLC) and their induced immune response in the form of autoantibodies. A database of cryptoproteins was computationally constructed and comprised all alternate open reading frames (altORFs) and ORFs identified in pseudogenes, noncoding RNAs, and untranslated regions of mRNAs that did not align with known canonical proteins. Proteomic profiles of seventeen lung adenocarcinoma (LUAD) cell lines were searched to evaluate the occurrence of cryptoproteins. To assess the immunogenicity, immunoglobulin (Ig)-bound cryptoproteins in plasmas were profiled by mass spectrometry. The specimen set consisted of plasmas from 30 newly diagnosed NSCLC cases, pre-diagnostic plasmas from 51 NSCLC cases, and 102 control plasmas. An analysis of LUAD cell lines identified 420 cryptoproteins. Plasma Ig-bound analyses revealed 90 cryptoproteins uniquely found in cases and 14 cryptoproteins that had a fold-change >2 compared to controls. In pre-diagnostic samples, 17 Ig-bound cryptoproteins yielded an odds ratio ≥2. Eight Ig-bound cryptoproteins were elevated in both pre-diagnostic and newly diagnosed cases compared to controls. Cryptoproteins represent a class of neoantigens that induce an autoantibody response in NSCLC.

Association of thyroid transcription factor-1 with the efficacy of immune-checkpoint inhibitors in patients with advanced lung adenocarcinoma

Background

We aimed to identify the relationship between thyroid transcription factor‐1 (TTF‐1) expression of lung adenocarcinoma and the efficacy of immune‐checkpoint inhibitor (ICI) therapy.

Methods

This retrospective multicenter study comprised patients with advanced lung adenocarcinoma treated with ICI monotherapy. We collected clinical medical records including data on TTF‐1 expression and analyzed the relationship between TTF‐1 expression and programmed death‐ligand 1 tumor proportion score (PD‐L1 TPS), objective response rate (ORR), progression‐free survival (PFS), and overall survival (OS).

Results

In total, 108 patients with lung adenocarcinoma were analyzed. The rate of TPS ≥1% and ≥50% in patients with positive TTF‐1 expression was significantly higher than that in patients with negative TTF‐1 expression (88% vs. 60%, p < 0.001; 65% vs. 24%, p < 0.001). The ORR was significantly higher in TTF‐1 positive patients than in TTF‐1‐negative patients (38% vs. 8%, p = 0.003). Among patients with TPS ≥50% and 1%–49%, the ORR in TTF‐1 positive and negative patients was 48% (26/54) versus 17% (1/6) (p = 0.21), and 32% (6/19) versus 11% (1/9) (p = 0.37), respectively. The ORR for patients with TPS <1% was 0% in both the TTF‐1 negative and positive cases. The median PFS and OS was significantly longer in TTF‐1‐positive patients than in TTF‐1‐negative patients (5.4 vs. 1.6 months, p < 0.001; 18.2 vs. 8.0 months, p = 0.041). Multivariate analysis revealed that TTF‐1‐negative status was an independent unfavorable prognostic factor for PFS.

Conclusion

Patients with TTF‐1‐positive status receiving ICI monotherapy showed better outcomes than those with TTF‐1‐negative lung adenocarcinoma.

Current Immunotherapeutic Strategies Targeting the PD-1/PD-L1 Axis in Non-Small Cell Lung Cancer with Oncogenic Driver Mutations

Treatment strategies targeting programed cell death 1 (PD-1) or its ligand, PD-L1, have been developed as immunotherapy against tumor progression for various cancer types including non-small cell lung cancer (NSCLC). The recent pivotal clinical trials of immune-checkpoint inhibiters (ICIs) combined with cytotoxic chemotherapy have reshaped therapeutic strategies and established various first-line standard treatments. The therapeutic effects of ICIs in these clinical trials were analyzed according to PD-L1 tumor proportion scores or tumor mutational burden; however, these indicators are insufficient to predict the clinical outcome. Consequently, molecular biological approaches, including multi-omics analyses, have addressed other mechanisms of cancer immune escape and have revealed an association of NSCLC containing specific driver mutations with distinct immune phenotypes. NSCLC has been characterized by driver mutation-defined molecular subsets and the effect of driver mutations on the regulatory mechanism of PD-L1 expression on the tumor itself. In this review, we summarize the results of recent clinical trials of ICIs in advanced NSCLC and the association between driver alterations and distinct immune phenotypes. We further discuss the current clinical issues with a future perspective for the role of precision medicine in NSCLC.

LncRNA NEAT1-miR-101-3p/miR-335-5p/miR-374a-3p/miR-628-5p-TRIM6 axis identified as the prognostic biomarker for lung adenocarcinoma via bioinformatics and meta-analysis

BACKGROUND

Overexpression of the tripartite motif containing 6 (TRIM6) is associated with dismal prognosis in cancer patients, but its exact roles in lung adenocarcinoma (LUAD) have not been reported.

METHODS

The roles of TRIM6 are identified by using The Cancer Genome Atlas (TCGA), TIMER2, Gene Expression Omnibus (GEO), etc., and the regulatory networks and related-prognostic biomarkers of TRIM6 are identified via the ENCORI and LNCAR databases in the LUAD progression.

RESULTS

TRIM6 expression level in LUAD tissues was significantly increased. TRIM6 over-expression level in LUAD patients was associated with smoking, clinical stage, histological type, lymph node metastasis, TP53 mutation and dismal prognosis, and related to prognosis-related age, race, sex, clinical stage and tumor purity of LUAD patients. TRIM6 overexpression was associated with the levels of CD8+ T cells, macrophages, neutrophils and myeloid dendritic cells, and correlated with the levels of LUAD immune cell markers CD8A, IRF5, CD163, VSIG4, MS4A4A, ITGAM, HLA-DPA1, NRP1, ITGAX, etc. TRIM6 might influence the progression of LUAD by regulating homologous recombination, oocyte meiosis, and ubiquitin-mediated proteolysis. LUAD patients with overexpression of miR-101-3p, miR-335-5p, miR-374a-3p, miR-628-5p, and NEAT1 had a poor prognosis.

CONCLUSIONS

NEAT1-miR-101-3p/335-5p/374a-3p/628-5p-TRIM6 network, which we constructed from our results, might be an important factor in the dismal prognosis of LUAD patients.