Involvement of ROS in the inhibitory effect of thermotherapy combined with chemotherapy on A549 human lung adenocarcinoma cell growth through the Akt pathway

Exosomal microRNA-506 inhibits biological activity of lung adenocarcinoma cells and increases sensitivity to cisplatin-based hyperthermia

Exosomal microRNAs (miRNAs) play a vital role in the occurrence and development of lung adenocarcinoma (LUAD). Based on the bioinformatics analyses, the current study sought to explore the effects of exosomal miR-506 on LUAD cell biology and the efficacy of cisplatin (CDDP)-based hyperthermia (HT). After sample preparation, we identified decreased miR-506 and elevated ATAD2. LUAD cells were subsequently transfected with miR-506 mimic, oe-ATAD2 and PI3K/AKT signaling pathway inhibitor LY294002 to analyze effects of the miR-506/ATAD2/PI3K/AKT axis on cell biological processes and chemoresistance. Effects of exosomal miR-506 on sensitivity of LUAD cells to CDDP-based HT were further assessed in a co-culture system of BMSC-derived exosomes and LUAD cells, which was also validated in tumor-bearing nude mice. miR-506 down-regulated ATAD2 to inhibit the PI3K/AKT signaling pathway, thereby inhibiting the malignant phenotypes of LUAD cells and augmenting LUAD cell sensitivity to CDDP-based HT. Further, BMSCs-derived exosomes harboring miR-506 sensitized LUAD cells to DDP/HT both in vitro and in vivo. Collectively, our findings revealed that exosomal miR-506 sensitized LUAD cells to CDDP-based HT by inhibiting ATAD2/PI3K/AKT signaling pathway, offering a potential therapeutic target for LUAD treatment.

Synergistic Anticancer Effect of a Combination of Paclitaxel and 5-Demethylnobiletin Against Lung Cancer Cell Line In Vitro and In Vivo

Lung cancer remains a highly prevalent disease and a leading cause of cancer-related deaths worldwide. Currently, exploring antitumor drugs derived from herbs used in traditional Chinese medicine is increasingly becoming an attractive area of research. Paclitaxel (PTX), a highly effective chemotherapeutic drug, is widely used for treating different cancers; however, the clinical use of PTX is dose limited because of its adverse side effects. Chemotherapeutic agents are being developed to enhance the anticancer activity of PTX, particularly for use in combination therapy. 5-Demethylnobiletin (5-DMN), a natural, active compound isolated from orange peel, has been reported to induce apoptosis in several cancer cell lines. In this study, we tested the synergistic anticancer antiproliferative effects of combinations of PTX and 5-DMN on CL1-5 lung cancer cells through the MTT and propidium iodide assays. After low-dose combination treatments (PTX and 5-DMN), a reduction in cell viability and a concomitant increase in apoptosis were observed in the CL1-5 cells. We propose that 5-DMN cooperates with PTX to induce apoptosis via the caspase pathway (by modulating caspase-3, caspase-8, and caspase-9 activities). Furthermore, we observed that the combination treatment significantly suppressed tumor growth in the nude mouse xenograft model. The results suggest that the synergistic effects of PTX and 5-DMN in lung cancer cells deserve particular attention and indicate the possibility of developing additional new strategies for treating lung cancer.

Synergistic anticancer effects of andrographolide and paclitaxel against A549 NSCLC cells

CONTEXT

Paclitaxel (PTX) is widely used in chemotherapy for cancer treatment; however, it has some serious side effects. Andrographolide (Andro) is a potential cancer therapeutic agent isolated from Andrographis paniculata (Burm. f.) Nees (Acanthaceae).

OBJECTIVE

The objective of this study is to evaluate the effects of PTX combined with Andro against A549 cells.

MATERIALS AND METHODS

The effects of 24-48 h treatment with 0.48-60.75 nM PTX and 5.10-328.0 μM Andro on cellular proliferation, apoptosis, cell cycle and intracellular reactive oxygen species (ROS) were determined by sulphorhodamine B assay, Annexin V-FITC/PI apoptosis detection, PI staining and ROS assay, respectively. Synergy was determined using combination index. The antitumour efficacy of 20 mg/kg PTX with 100 mg/kg Andro was studied in a xenograft murine model.

RESULTS

IC₅₀ value of the PTX combined with Andro against A549 cells was 0.5-7.4 nM, which was significantly lower than that of PTX (15.9 nM). PTX with 10 μM Andro caused (1.22-1.27)-fold apoptosis and 1.7-fold ROS accumulation compared with PTX alone. N-Acetylcysteine, a ROS scavenger, blocked this synergy in vitro. In contrast, G2/M phase cell cycle arrest resulting from PTX was not potentiated by Andro. Moreover, PTX in combination with Andro inhibited the growth of A549 transplanted tumours by 98%.

DISCUSSION AND CONCLUSION

The results indicate that the combination of PTX and Andro exert significant synergistic anticancer effect on A549 cells in vitro and in vivo. The synergy may be the result of the accumulation of ROS. The combination of Andro and PTX represents a potential strategy for the treatment of A549 cells.

Is thermochemotherapy with the Synergo system a viable treatment option in patients with recurrent non-muscle-invasive bladder cancer?

OBJECTIVES

To prospectively evaluate the outcome of combined microwave-induced bladder wall hyperthermia and intravesical mitomycin C instillation (thermochemotherapy) in patients with recurrent non-muscle-invasive bladder cancer.

METHODS

Between 2003 and 2009, 21 patients (median age 70 years, range 35-95 years) with recurrent non-muscle-invasive bladder cancer (pTaG1-2 n = 9; pTaG3 n = 3; pT1 n = 9; concurrent pTis n = 8) were prospectively enrolled. Of 21 patients, 15 (71%) had received previous intravesical instillations with bacillus Calmette-Guérin, mitomycin C and/or farmorubicin. Thermochemotherapy using the Synergo system was carried out in 11 of 21 patients (52%) with curative intent, and in 10 of 21 patients (48%) as prophylaxis against recurrence.

RESULTS

The median number of thermochemotherapy cycles per patient was six (range 1-12). Adverse effects were frequent and severe: urinary urgency/frequency in 11 of 21 patients (52%), pain in eight of 21 patients (38%) and gross hematuria in five of 21 patients (24%). In eight of 21 patients (38%), thermochemotherapy had to be abandoned because of the severity of the adverse effects (pain in 3/8, severe bladder spasms in 2/8, allergic reaction in 2/8, urethral perforation in 1/8). Overall, six of 21 patients (29%) remained free of tumor after a median follow up of 50 months (range 1-120), six of 21 patients (29%) had to undergo cystectomy because of multifocal recurrences or cancer progression and seven of 21 patients (33%) died (2/7 of metastatic disease, 5/7 of non-cancer related causes).

CONCLUSIONS

Given the high rate of severe side-effects leading to treatment discontinuation, as well as the limited tumor response, thermochemotherapy should be offered only in highly selected cases of recurrent non-muscle-invasive bladder cancer.