Qian Wang

Head and neck adenoid cystic carcinoma (HNACC) is an uncommon but aggressive salivary gland malignancy with high recurrence and metastasis rates. Its "immune-cold" phenotype limits the efficacy of systemic therapy, and thus, radiotherapy is the principal treatment for unresectable cases. However, frequent radioresistance suggests the involvement of distinct molecular drivers. This study investigated the role of CCL5 in HNACC radioresistance, its mechanistic link to autophagy, and its potential as a radiosensitization target. Transcriptome sequencing of radiation-sensitive (SACC-83) and radiation-tolerant (SACC-LM) cell lines, integrated with GEO datasets, identified candidate genes. For functional validation, genetic manipulation and pharmacological inhibition with the CCL5/CCR5 antagonist maraviroc were performed. Cellular proliferation, invasion, apoptosis, cell cycle, and radiosensitivity were assessed. Autophagy was examined by transmission electron microscopy and western blotting, with a focus on AMPK/mTOR signaling. A xenograft mouse model was used to evaluate the therapeutic effect of maraviroc combined with radiotherapy. CCL5 expression was elevated in radioresistant cells and further induced by irradiation. High CCL5 levels promoted proliferation, migration, and invasion while reducing radiation-induced apoptosis and G₂/S arrest. Mechanistically, CCL5 activated AMPK, suppressed mTOR, and enhanced autophagy, supporting cell survival under radiation stress. CCL5 inhibition reduced autophagy, restored radiosensitivity, and synergized with irradiation, whereas autophagy activation reversed these effects. In vivo, maraviroc combined with radiotherapy decreased tumor burden, suppressed CCL5 expression, and inhibited autophagy. CCL5 promotes radioresistance in HNACC through maintenance of AMPK/mTOR-dependent autophagy. Targeting the CCL5/CCR5 axis enhances radiosensitivity and represents a promising therapeutic strategy. Not applicable.

Radiotherapy is a vital treatment agent for lung adenocarcinoma (LUAD) patients, while radioresistance remains a major factor in treatment failure. Here, we aimed to elucidate how signal transducer and activator of transcription 1 (STAT1) affected sensitivity to carbon ion irradiation for LUAD cells in vivo and in vitro. The results of colony formation, CCK-8, EdU, and calcein-AM/PI double-staining assays demonstrated that the overexpression of STAT1 markedly enhanced the inhibitory effect of carbon ion irradiation on the viability of LUAD cells (A549 and PC9 cells). Lactate dehydrogenase (LDH) leakage assays identified ferroptosis as the predominant form of cell death induced by STAT1 overexpression in LUAD cells. Meanwhile, the ferroptosis-related PCR array confirmed heme oxygenase 1 (HO-1) as a potential effector molecule of STAT1-induced ferroptosis. Mechanistically, STAT1 overexpression resulted in phosphorylation at the serine 727 residue, triggering the upregulation of HO-1 expression and subsequent labile iron pool (LIP) accumulation. This process amplified the Fenton reaction, leading to increased reactive oxygen species (ROS), lipid peroxides (LPO), and glutathione (GSH) depletion. HO-1 knockdown eliminated the ferroptosis induced by the overexpression of STAT1. Furthermore, in vivo experiments showed that STAT1 overexpression enhanced the effect of carbon ion irradiation in inhibiting the growth of subcutaneous tumors in nude mice. These findings provide the foundation for the development of the STAT1-HO-1 axis as a radiosensitization target for LUAD patients.

Objectives: Cancer cells with ‘stemness’ are generally resistant to chemoradiotherapy. This study aims to compare the differences in radiation sensitivity of A549 and CD44⁺A549 stem-like cells to X-rays and carbon ion radiation (C-ions), and to find a target that can kill cancer stem-like cells (CSCs) of non-small cell lung cancer (NSCLC). Methods: The study used two cell lines (A549 and CD44⁺A549). The tumorigenicity of cells was tested with animal experiments. The cells were irradiated with X-rays and C-ions. Cell viability was detected using the CCK-8 and EdU assay. A liquid chromatograph-mass spectrometer (LC–MS) helped detect metabolic differences. Protein and mRNA expression were detected using a Western blot, reverse transcription-quantitative (RT-qPCR), and PCR array. The autophagic activity was monitored with a CYTO-ID^® Autophagy Detection Kit 2.0. Immunofluorescence and co-immunoprecipitation helped to observe the localization and interaction relationships. Results: First, we verified the radio-resistance of CD44⁺A549 stem-like cells. LC-MS indicated the difference in autophagy between the two cells, followed by establishing a correlation between the radio-resistance and autophagy. Subsequently, the PCR array proved that TGM2 is significantly upregulated in CD44⁺A549 stem-like cells. Moreover, the TGM2 knockdown by small interfering RNA could decrease the radio-resistance of CD44⁺A549 cells. Bioinformatic analyses and experiments showed that TGM2 is correlated with the expression of CD44 and LC3B. Additionally, TGM2 could directly interact with LC3B. Conclusions: We established the CD44-TGM2-LC3 axis: CD44 mediates radio-resistance of CD44⁺A549 stem-like cells through TGM2 regulation of autophagy. Our study may provide new biomarkers and strategies to alleviate the radio-resistance of CSCs in NSCLC.

Mitochondria are organelles with double-membrane structure of inner and outer membrane, which provides main energy support for cell growth and metabolism. Reactive oxygen species (ROS) mainly comes from mitochondrial and can cause irreversible damage to cells under oxidative stress. Thus, mitochondrial homeostasis is the basis for maintaining the normal physiological function of cells and mitophagy plays a pivotal role in the maintenance of mitochondrial homeostasis. At present, to enhance the sensitivity of cancer cells to radiotherapy and chemotherapy by regulating mitochondria has increasingly become a hot spot of cancer therapy. It is particularly important to study the effect of ionizing radiation (IR) on mitochondria and the role of mitophagy in the radiosensitivity of cancer cells. Most of the existing reviews have focused on mitophagy-related molecules or pathways and the impact of mitophagy on diseases. In this review, we mainly focus on discussing the relationship between mitophagy and radiosensitivity of cancer cells around mitochondria and IR.

Purpose The existence of cancer stem cells (CSCs) is closely related to tumor recurrence, metastasis, and resistance to chemoradiotherapy. In addition, given the unique physical and biological advantages of charged particle, we hypothesized that charged particle irradiation would produce strong killing effects on CSCs. The purpose of our systematic review is to evaluate the biological effects of CSCs irradiated by charged particle, including proliferation, invasion, migration, and changes in the molecular level. Methods We searched PubMed, EMBASE, and Web of Science until 17 march 2022 according to the key words. Included studies have to be vitro studies of CSCs irradiated by charged particle. Outcomes included one or more of radiation sensitivity, proliferation, metastasis, invasion, and molecular level changes, like DNA damage after been irradiated. Results Eighteen studies were included in the final analysis. The 18 articles include 12-carbon ion irradiation, 4-proton irradiation, 1 α-particle irradiation, 1-carbon ion combine proton irradiation. Conclusion Through the extraction and analysis of data, we came to this conclusion: CSCs have obvious radio-resistance compared with non-CSCs, and charged particle irradiation or in combination with drugs could overcome this resistance, specifically manifested in inhibiting CSCs’ proliferation, invasion, migration, and causing more and harder to repair DNA double-stranded breaks (DSB) of CSCs.

Background We analyzed the relationship among peripheral blood lymphocytes, exposed sternum and vertebra body bone marrow (BM), and overall survival (OS) to find BM dosimetric parameters of lymphopenia during chemoradiotherapy (CRT) for patients with esophageal squamous cell carcinoma (ESCC). Methods We examined 476 ESCC patients from January 2012 to January 2015, all of whom received concurrent or sequential CRT. Absolute lymphocyte counts (ALC) during radiotherapy (RT) of each patient were collected from the routine workup at the following RT times: pretreatment ALC (ALC0), at 1–5, 6–10, 11–15, 16–20, and 21–25, and more than 26 sessions (called ALC1–6, respectively). The sternum and vertebral body BM were delineated in accordance with uniform standards, and the irradiated volumes were calculated by dose-volume histograms (DVH). The Kaplan–Meier method and Cox proportional hazards regression were used to analyze the survival of the patients. Comparisons of DVH were performed using the Mann–Whitney U test or two-sample t-test where appropriate. Results A relative volume of sternum BM irradiated by more than 20 Gy could clearly affect the peripheral blood lymphocytes. The V20 of sternum BM and V50 of vertebra body BM were related to the OS of the patients, and the level of ALC2 (at 6–10 times of RT) could predict the outcomes of patients. The Cox regression analyses showed that the 218 patients with ALC2 ≥ 0.8 × 10⁹/L had a significantly higher OS (47.0 months vs. 30.9 months, p < 0.0001) than the 258 patients with ALC2 < 0.8×10⁹/L. Conclusion In patients with ESCC, the relative volume of sternum BM irradiated by more than 20 Gy was associated with lymphocytes. Patients with ALC2 ≥ 0.8 × 10⁹/L had a significantly higher OS. The V20 of the sternum BM, the V50 of the vertebra body BM, and the level of ALC2 were significant prognostic factors in patients with ESCC.