Chemotherapy beyond first-line in stage IV metastatic non-small cell lung cancer

Long non‑coding RNA TP73‑AS1 accelerates the progression and cisplatin resistance of non‑small cell lung cancer by upregulating the expression of TRIM29 via competitively targeting microRNA‑34a‑5p

Non-small cell lung cancer (NSCLC) is a leading subtype of lung cancer, with high mortality rates. Recently, long non-coding RNAs (lncRNAs) have been associated with NSCLC. The present study aimed to examine the role of the TP73 antisense RNA 1 (TP73-AS1) lncRNA in NSCLC. TP73-AS1 and microRNA(miR)-34a-5p expression levels were measured using reverse transcription-quantitative PCR (RT-qPCR) and chromogenic in situ hybridization (CISH). Cell proliferation, apoptosis, migration and invasion was determined using Cell Counting Kit-8 (CCK-8), flow cytometry, Transwell and Matrigel assays, respectively. The median inhibitory concentration (IC₅₀) value of cisplatin (cis-diamminedichloroplatinum; DDP) was assessed using a CCK-8 assay. The interaction between miR-34a-5p and TP73-AS1 or tripartite motif-containing 29 (TRIM29) was predicted using microRNA.org and Starbase, then verified using a dual-luciferase reporter assay. The expression of TRIM29 was quantified at the mRNA and protein level using RT-qPCR and western blot analysis, respectively. TP73-AS1 was significantly upregulated, while miR-34a-5p was downregulated in NSCLC tissues and cells. Functionally, TP73-AS1 knockdown inhibited proliferation, migration, invasion and DDP resistance, whilst inducing apoptosis in NSCLC cells. miR-34a-5p was identified as a target for TP73-AS1, and its inhibition reversed the effects of TP73-AS1 knockdown on NSCLC cells. In addition, TRIM29 was targeted by miR-34a-5p, and its overexpression reversed the effects of miR-34a-5p. Moreover, TP73-AS1 acted as a molecular sponge for miR-34a-5p, increasing the expression of TRIM29. In conclusion, TP73-AS1 contributed to proliferation, migration and DDP resistance but inhibited apoptosis of NSCLC cells by upregulating TRIM29 and sponging miR-34a-5p.

Demethoxycurcumin-carrying chitosan-antibody core-shell nanoparticles with multitherapeutic efficacy toward malignant A549 lung tumor: from in vitro characterization to in vivo evaluation

Targeting controlled release core-shell nanocarriers with the potential to overcome multidrug resistant (MDR) lung cancer were prepared based on demethoxycurcumin (DMC) loaded amphiphilic chitosan nanoparticles coated with an anti-EGFR antibody layer. The nanocarriers were characterized with regard to size with dynamic light scattering, SEM, and TEM. The characterization confirmed the nanocarriers to have a surface coating of the anti-EGFR antibody and a final size excellently suited for circulating targeting nanocarriers, i.e., <200 nm in diameter. In vitro drug release revealed extended quasi-Fickian release from the nanocarriers, with the anti-EGFR layer further reducing the release rate. Cell culture experiments using normoxic and MDR hypoxic cells overexpressing EGFR confirmed improved DMC delivery for anti-EGFR coated particles and revealed that the DMC was delivered to the cytoplasmic region of the cells, forming nanoprecipitates in lysosomes and endosomes. The effective endocytosis and targeting of the core-shell nanoparticles resulted in the nanocarriers achieving high cytotoxicity also against MDR cells. The therapeutic potential was further confirmed in an A549 xenograft lung tumor mouse model, where DMC loaded core-shell nanocarriers achieved about 8-fold reduction in tumor volume compared with control group over the 8 weeks of the investigation. Both in vitro and in vivo data suggest the anti-EGFR coated core-shell nanocarriers as highly promising for treatment of hypoxic MDR cancers, especially for non-small cell lung cancer.