Background: Long noncoding RNAs (lncRNAs) are a kind of molecule that cannot code proteins, and their expression is dysregulated in diversified cancers. LncRNA PITPNA-AS1 has been shown to act as a tumor promoter in a variety of malignancies, but its function and regulatory mechanisms in lung squamous cell carcinoma (LUSC) are yet unknown. Methods:The mRNA and protein expression of genes were examined by RT-qPCR, western blot, and IHC assay. The cell proliferation, migration, invasion, and stemness were detected through CCK-8, colony formation, Transwell and spheroid formation assays. The CD44 + and CD166 + -positive cells were detected through flow cytometry.The binding ability among genes through luciferase reporter and RNA pull-down assays. The tumor growth was detected through in vivo nude mice assay. Results:The lncRNA PITPNA-AS1 had increased expression in LUSC and was linked to a poor prognosis. In LUSC, PITPNA-AS1 also enhanced cell proliferation, migration, invasion, and stemness. This mechanistic investigation showed that PITPNA-AS1 absorbed miR-223-3p and that miR-223-3p targeted PTN. MiR-223-3p inhibition or PTN overexpression might reverse the inhibitory effects of PITPNA-AS1 suppression on LUSC progression, as demonstrated by rescue experiments. In addition, the PITPNA-AS1/miR-223-3p/PTN axis accelerated tumor development in vivo. Conclusions: It is the first time we investigated the potential role and ceRNA regulatory mechanism of PITPNA-AS1 in LUSC. The data disclosed that PITPNA-AS1 upregulated PTN through sponging miR-223-3p to enhance the onset and progression of LUSC. These findings suggested the ceRNA axis may serve as a promising therapeutic biomarker for LUSC patients.

Tracheobronchial tuberculosis (TB) leads to airway stenosis, irreversible airway damage and even death. The present study aimed to identify biomarkers for the diagnosis of tracheobronchial stenosis (TBS) secondary to tracheobronchial TB. A cohort was recruited, including patients with TBS after tracheobronchial TB, TBS after tracheal intubation or tracheotomy (TIT) and no stenosis of early-stage lung cancer,. Proteomic profiling was performed to gain insight into the mechanisms of the pathological processes. Differentially expressed proteins in the serum and bronchial alveolar lavage fluid (BALF) from patients were detected by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Subsequently, ELISA was performed to validate the changes of protein levels in an additional cohort. MALDI-TOF MS revealed that 8 peptides in the serum, including myeloid-associated differentiation marker, keratin type I cytoskeletal 18, fibrinogen α-chain, angiotensinogen (AGT), apolipoprotein A-I (APOAI), clusterin and two uncharacterized peptides, and nine peptides in BALF, including argininosuccinate lyase, APOAI, AGT and five uncharacterized peptides, were differentially expressed (molecular-weight range, 1,000-10,000 Da) in the TB group compared with the TIT group. The ELISA results indicated that the changes in the protein levels had a similar trend as those identified by proteomic profiling. In conclusion, the present study identified proteins that may serve as potential biomarkers and provide novel insight into the molecular mechanisms underlying TBS after tracheobronchial TB.