Iodine-125 interstitial brachytherapy reduces tumor growth via Warburg effect inhibition in non-small cell lung cancer A549 ×enografts

LncRNA DGCR5 Silencing Enhances the Radio-Sensitivity of Human Esophageal Squamous Cell Carcinoma via Negatively Regulating the Warburg Effect

Recently, long noncoding RNAs (lncRNAs) and the Warburg effect have been reported to play important roles in the radio-sensitivity of tumor cells. Survival correlates with pathologic responses to chemoradiotherapy and improving responses to radiation may translate into improved survival. This study aims to examine the effects and mechanisms of lncRNA DGCR5 and the Warburg effect on ESCC cell radiosensitivity. Levels of DGCR5, miR-195 and hexokinase 2 (HK2) expression in ESCC tissues and cells were determined and their clinical significance was analyzed. TE-1 and KYSE150 cells received a 6 Gy dose of X-ray radiation and their survival, proliferation and apoptosis were evaluated using colony formation assays, CCK-8 assays, and flow cytometry, respectively. Lactic acid production and glucose consumption were also examined in both cell types. Finally, the expression of apoptotic proteins was assessed using Western blotting. Analysis revealed that DGCR5 and HK2 were overexpressed in ESCC, while miR-195 was under expressed. Moreover, it was demonstrated that down-regulation of DGCR5 inhibited cell proliferation and promoted apoptosis, resulting in increased radiosensitivity by inhibition of the Warburg Effect. Conversely, overexpression of DGCR5 exhibited an opposite phenomenon in vitro. When investigating the mechanism, we identified that miR-195 was predicted to be a direct downstream target of DGCR5. Meanwhile, HK2 was predicted to be a direct downstream target of miR-195. Dual-luciferase reporter assays verified the direct interaction between these molecules. Finally, in vivo experiments were utilized to validate that knockdown of DGCR5 suppressed the Warburg effect via targeting of the miR-195/HK2 axis to increase the radiosensitivity of ESCC. Our study reveals that down-regulation of DGCR5 resulted in inhibition of the Warburg effect through interaction with the miR-195/HK2 axis increasing ESCC cell apoptosis after irradiation, thus enhancing cell radiosensitivity.

Scutellarin improves the radiosensitivity of non-small cell lung cancer cells to iodine-125 seeds via downregulating the AKT/mTOR pathway

Background

In our previous study, we indicated that scutellarin (SCU) induced an anticancer effect in A549 cells. However, whether SCU regulates the radiosensitivity of non‐small cell lung cancer (NSCLC) and its related mechanism is still unclear.

Methods

In this study, we explored the anticancer effect induced by iodine‐125 (¹²⁵I) and SCU at a sensitizing concentration in A549 and H1975 cells. Cellular apoptosis and proliferation were detected by flow cytometry, Bcl‐2/Bax expression level, cell cycle, CCK‐8, and EdU staining. A tumor model using nude mice was also carried out to investigate the combined effect of ¹²⁵I and SCU in vivo. In addition, the expression level of AKT/mTOR pathway was detected to investigate whether it is linked to the anticancer effect of ¹²⁵I and SCU.

Results

SCU at a sensitizing concentration promoted the ¹²⁵I‐induced apoptosis and antiproliferative effect in A549 and H1975 cells. Moreover, the same results were obtained in vivo. Based on our findings, the AKT/mTOR pathway was significantly downregulated after combined treatment with ¹²⁵I and SCU.

Conclusions

The results of our study suggested that SCU promotes the anticancer effects induced by ¹²⁵I in NSCLC cells by downregulating the AKT/mTOR pathway and lays a foundation for future application of this combined treatment.

Lobaplatin Enhances Radioactive 125I Seed-Induced Apoptosis and Anti-Proliferative Effect in Non-Small Cell Lung Cancer by Suppressing the AKT/mTOR Pathway

Introduction

In recent years, radioactive ¹²⁵I seed implantation combined with chemotherapy has been regarded as a safe and effective treatment for advanced non-small cell lung cancer (NSCLC). However, the mechanism underlying this success is still unclear.

Methods

In this study, we investigated the apoptosis and anti-proliferative effect induced by ¹²⁵I in A549, H1975, and H157 cells and determined whether a sensitizing concentration of lobaplatin (LBP) could enhance these effects. We performed in vitro experiments on A549, H1975, and H157 cells; we investigated the effects of ¹²⁵I or lobaplatin (LBP) alone, or in combination, on cellular apoptosis and proliferation by performing flow cytometry, Bax/Bcl2 ratio, TUNEL, cell viability assay, cell cycle, and EdU. To further verify our findings, a subcutaneous tumor mouse model was established. Moreover, AKT/mTOR pathway was detected to determine whether this pathway was involved in the anti-cancer effect of ¹²⁵I and LBP by up-regulating or down-regulating the expression of mTOR.

Results

Based on our results, the sensitizing concentration of LBP could enhance the ¹²⁵I-induced apoptosis and anti-proliferation effect. Furthermore, the subcutaneous tumor mouse model obtained the consistent results. More importantly, the AKT/mTOR pathway was down-regulated after the treatment of ¹²⁵I and LBP, and the anti-cancer effect of ¹²⁵I and LBP could be compromised by up-regulating the mTOR expression.

Conclusion

Our study proved that LBP promotes the apoptotic and anti-proliferative effects of ¹²⁵I in NSCLC cells by inhibiting the AKT/mTOR pathway and provides a foundation for future studies and enhanced combinatorial approaches for NSCLC in the clinical setting.

125I Seed Brachytherapy Combined with Single-Agent Chemotherapy in the Treatment of Non-Small-Cell Lung Cancer in the Elderly: A Valuable Solution

Purpose

The aim of this study was to compare the effectiveness and safety of CT-guided ¹²⁵I seed brachytherapy combined with single-agent chemotherapy versus combined chemotherapy in the treatment of elderly NSCLC.

Materials and Methods

We retrospectively analyzed 110 patients (64 men and 46 women; mean age=71.25±7.14 years) who were diagnosed with NSCLC without distant metastases between January 2015 and May 2020. A total of 50 patients received ¹²⁵I brachytherapy combined with single-agent chemotherapy (group A), whereas 60 patients received combined chemotherapy (group B). The response to therapy and adverse effect were compared between groups. The local response rate was evaluated by CT. Progression-free survival (PFS) and overall survival (OS) data were obtained through clinical follow-up.

Results

All patients had been treated and were followed-up for 3-60 months. The median OS and PFS were 23.71±1.41 months (95% CI=20.95-26.47) vs 16.12±0.93 months (95% CI=14.31-17.93) (P<0.05) and 15.08±0.85 months (95% CI=13.42-16.74) vs 10.03±0.53 months (95% CI=9.01-11.06) (P<0.05) in group A and group B, respectively. The local response rate and clinical symptoms of patients in group A were significantly relieved when compared with group B. Severe complications were not observed in either group.

Conclusion

CT-guided ¹²⁵I seed brachytherapy combined with single-agent chemotherapy is an effective and safe therapy and shows promising results compared to combined chemotherapy alone for NSCLC in the elderly. A randomized study will be needed to assess the superiority of this combined modality treatment.