Sunmi Jo

The “oxygen effect” improves radiation efficacy; thus, tumor cell oxygen concentration is a crucial factor for improving lung cancer treatment. In the current study, we aimed to identify aerobic exercise-induced changes in oxygen concentrations in non-small cell lung cancer (NSCLC) cells. To this end, an NSCLC xenograft mouse model was established using human A549 cells. Animals were subsequently subjected to aerobic exercise and radiation three times per week for 2 weeks. Aerobic exercise was performed at a speed of 8.0 m/m for 30 min, and the tumor was irradiated with 2 Gy of 6 MV X-rays (total radiation dose 12 Gy). Combined aerobic exercise and radiation reduced NSCLC cell growth. In addition, the positive effect of aerobic exercise on radiation efficacy through oxygenation of tumor cells was confirmed based on hypoxia-inducible factor-1 and carbonic anhydrase IX expression. Finally, whole-transcriptome analysis revealed the key factors that induce oxygenation in NSCLC cells when aerobic exercise was combined with radiation. Taken together, these results indicate that aerobic exercise improves the effectiveness of radiation in the treatment of NSCLC. This preclinical study provides a basis for the clinical application of aerobic exercise to patients with NSCLC undergoing radiation therapy.

In the field of radiation therapy, the oxygen effect is the most important key factor in increasing the treatment efficiency. Many researchers have studied methods for causing reoxygenation inside tumor cells. This study was conducted to determine whether reoxygenation is induced through relatively accessible aerobic exercise. The animals were injected with 5×10⁵ A549 cells in the flank and tumors were allowed to develop. Upon identification of a palpable tumor (tumor volume of 200 mm³), radiation and aerobic exercise combined treatment was administered for 2 weeks. Radiation was irradiated immediately after performing aerobic exercise. Radiation was irradiated with 2 Gy to the tumor and aerobic exercise was performed at a speed of 8.0 for 30 minutes. Next, 4–6 µm sections were prepared and stained with hematoxylin and eosin (H&E) following standard procedures. For Ki-67 and CA IX, HIF-1α, 4-hydroxynonenal & nitrotyrosine immunohistochemistry. We confirmed that lung cancer cell growth was suppressed when aerobic exercise was combined with radiotherapy through in vivo xenograft studies. In addition, the effect of aerobic exercise on the radiation therapy effect through reoxygenation in tumor cells was confirmed. We also confirmed that HIF-1α and CA IX expressions were significantly increased in the combination treatment group. Lastly, we performed transcriptome analysis to discover the key factors that aerobic exercise induces reoxygenation. Taken together, the results suggest that the effect of radiation therapy is enhanced through aerobic exercise, which is relatively easy to apply.

Although there are many patients with brain tumors worldwide, there are numerous difficulties in overcoming brain tumors. Among brain tumors, glioblastoma, with a 5-year survival rate of 5.1%, is the most malignant. In addition to surgical operations, chemotherapy and radiotherapy are generally performed, but the patients have very limited options. Temozolomide is the most commonly prescribed drug for patients with glioblastoma. However, it is difficult to completely remove the tumor with this drug alone. Therefore, it is necessary to discuss the potential of anticancer drugs, other than temozolomide, against glioblastomas. Since the discovery of cisplatin, platinum-based drugs have become one of the leading chemotherapeutic drugs. Although many studies have reported the efficacy of platinum-based anticancer drugs against various carcinomas, studies on their effectiveness against brain tumors are insufficient. In this review, we elucidated the anticancer effects and advantages of platinum-based drugs used in brain tumors. In addition, the cases and limitations of the clinical application of platinum-based drugs are summarized. As a solution to overcome these obstacles, we emphasized the potential of a novel approach to increase the effectiveness of platinum-based drugs.

Myeloid sarcoma (MS) is a rarely encountered extramedullary localized tumor that is composed of immature myeloid cells. We reported an extremely rare case of MS with concurrent bone marrow (BM) involvement that invaded into a preexisting sebaceous lymphadenoma in the parotid gland and neck lymph nodes. Prompted by this case, we also present a literature review of MS invasion into salivary glands. A 62-year-old man was initially diagnosed with carcinoma that arose in a sebaceous lymphadenoma in the parotid gland, through a total parotidectomy with neck dissection. After an extensive histopathological review that included immunohistochemistry, a pathologic diagnosis of MS with infiltration into the sebaceous lymphadenoma with concurrent BM involvement was confirmed. MS is difficult to diagnose accurately; herein, we analyzed the clinical presentations and effectiveness of the various diagnostic methods with a review of the literature. There are 17 cases, including our case, reported in 13 studies. Of the cases in which the salivary glands were affected, 10 involved the parotid gland, six involved the submandibular gland, and one involved both. Isolated invasion of the salivary gland was found in one case of parotid gland invasion and three cases of submandibular gland invasion. In 13 cases, the salivary glands were affected by various other lesions. Although there were no incidences of isolated MS, six patients were diagnosed with secondary MS and eight patients with MS with BM involvement, including this case. The diagnosis of MS is difficult given its rarity, and a high index of suspicion and integrated radiologic and careful histopathologic evaluation are required. Most cases of MS infiltrating the salivary gland might be indicated by the possibility of BM involvement. MS with BM involvement predicts poor prognosis and the need for intensive systemic treatment.

Purpose: Hyperthermia (HT), a clinical treatment involving delivery of heat to tumors, has been used in combination with traditional chemotherapy and radiotherapy to enhance their effects. However, the molecular mechanism underlying the high efficacy of combination therapy is not clear. This study was conducted to identify the molecular mechanism underlying the sensitization of lung cancer to radiotherapy by HT. Materials and methods: Nuclear receptor subfamily 4, group A, member 3 (NR4A3) and Krüppel-like factor 11 (KLF11) expression in non-small-cell lung cancer cells was confirmed by performing real-time quantitative reverse transcription–polymerase chain reaction. Tumor cell proliferation and apoptosis were assessed via a colony-forming assay and Annexin V/propidium iodide staining. Results and conclusions: Expression profile analysis revealed elevated levels of NR4A3 and KLF11 in A549 lung cancer cells after treatment with HT combined with radiation. We also confirmed that NR4A3 and KLF11 induced apoptosis and inhibited cell proliferation by elevating intracellular reactive oxygen species levels. Knockdown of NR4A3 or KLF11 using siRNA led to decreased effects of radiohyperthermia. Finally, the effect of these two factors on lung cancer progression was evaluated by in vivo xenograft studies. Taken together, the results suggest that NR4A3 and KLF11 are critical for increasing the efficacy of radiotherapy in combination with HT.

Radiotherapy is a standard treatment option for patients with glioblastoma (GBM). Although it has high therapeutic efficacy, some proportion of the tumor cells that survive after radiotherapy may cause side effects. In this study, we found that fructose 1,6-bisphosphatase 1 (FBP1), a rate-limiting enzyme in gluconeogenesis, was downregulated upon treatment with ionizing radiation (IR). Ets1, which was found to be overexpressed in IR-induced infiltrating GBM, was suggested to be a transcriptional repressor of FBP1. Furthermore, glucose uptake and extracellular acidification rates were increased upon FBP1 downregulation, which indicated an elevated glycolysis level. We found that emodin, an inhibitor of phosphoglycerate mutase 1 derived from natural substances, significantly suppressed the glycolysis rate and IR-induced GBM migration in in vivo orthotopic xenograft mouse models. We propose that the reduced FBP1 level reprogrammed the metabolic state of GBM cells, and thus, FBP1 is a potential therapeutic target regulating GBM metabolism following radiotherapy.

Lung Cancer Subcommittee of Korean Radiation Oncology Group (KROG) has recently launched a prospective clinical trial (KROG 17-06) of hippocampus-sparing whole brain radiotherapy (HS-WBRT) with simultaneous integrated boost (SIB) in treating multiple brain metastases from non-small cell lung cancer. In order to improve trial quality, dummy run studies among the participating institutions were designed. This work reported the results of two-step dummy run procedures of the KROG 17-06 study. Two steps tested hippocampus contouring variability and radiation therapy planning compliance. In the first step, the variation of the hippocampus delineation was investigated for two representative cases using the Dice similarity coefficients. In the second step, the participating institutions were requested to generate a HS-WBRT with SIB treatment plan for another representative case. The compliance of the treatment plans to the planning protocol was evaluated. In the first step, the median Dice similarity coefficients of the hippocampus contours for two other dummy run cases changed from 0.669 (range, 0.073 to 0.712) to 0.690 (range, 0.522 to 0.750) and from 0.291 (range, 0.219 to 0.522) to 0.412 (range, 0.264 to 0.598) after providing the hippocampus contouring feedback. In the second step, with providing additional plan priority and extended dose constraints to the target volumes and normal structures, we observed the improved compliance of the treatment plans to the planning protocol. The dummy run studies demonstrated the notable inter-institutional variability in delineating the hippocampus and treatment plan generation, which could be decreased through feedback from the trial center.

Recent studies revealed that metabolic stress influences the outcomes of breast cancer treatment. We sought to evaluate the prognostic effect of type 2 diabetes and find the molecular mechanism of relapses in postoperative HER-2+ breast cancer patients treated with HER-2 targeted therapy.

Background/Aims: Non-alcoholic fatty liver disease (NAFLD) is an emerging metabolic disease. Although it leads to severe hepatic diseases including steatohepatitis, cirrhosis, and hepatic cancer, little is known about therapy to prevent and cure hepatic steatosis, the first step of NAFLD. We conducted this investigation to unveil the mechanism of hepatic steatosis. Methods: We established a novel chronic NAFLD mouse model through whole body irradiation and verified the model through histological and biochemical analysis. To find molecular mechanism for hepatic steatosis, we analyzed hepatic transcriptomic profiles in this model and selected target molecule. To induce the expression of lactotransferrin (Ltf) and regulate the NAFLD, growth hormone (GH) and coumestrol was introduced to hepatocyte and mice. The universal effect of coumestrol was confirmed by administration of coumestrol to NAFLD mouse model induced by high-fructose, high-fat, and MCD diet. Results: It was observed that decreased hepatic Ltf expression led to excessive hepatic lipid accumulation in NAFLD mouse. Furthermore, we found that GH was decreased in irradiated mice and functioned as an upstream regulator of Ltf expression. It was observed that GH could stimulate Ltf expression and prevent uptake of dietary lipids in hepatocytes, leading to rescue of NAFLD. Finally, we suggested that coumestrol, a kind of isoflavonoid, could be used as an inducer of hepatic Ltf expression through cooperation with the GH signaling pathway both in vitro and in vivo. Conclusions: Hepatic Ltf prevents hepatic steatosis through inhibition of dietary lipid uptake in radiation-induced NAFLD mouse model. We also suggest coumestrol as a drug candidate for prevention of NAFLD.

Cranial irradiation is the main therapeutic strategy for treating primary and metastatic brain tumors. However, radiation is well-known to induce several unexpected side effects including emotional disorders. Although radiation-induced depression may cause decreased quality of life after radiotherapy, investigations of its molecular mechanism and therapeutic strategies are still insufficient. In this study, we found that behavioral symptoms of depression on mice models with the decrease of BrdU/NeuN- and Dcx-positive populations and MAP-2 expression in hippocampus were induced by cranial irradiation, and transthyretin (TTR) was highly expressed in hippocampus after irradiation. It was shown that overexpression of TTR resulted in the inhibition of retinol-mediated neuritogenesis. PAK1 phosphorylation and MAP-2 expression were significantly reduced by TTR overexpression following irradiation. Moreover, we observed that treatment of allantoin and neferine, the active components of Nelumbo nucifera, interrupted irradiation-induced TTR overexpression, consequently leading to the increase of PAK1 phosphorylation, neurite extension, BrdU/NeuN- and Dcx-positive populations, and MAP-2 expression. Behavioral symptoms of depression following cranial irradiation were also relieved by treatment of allantoin and neferine. These findings demonstrate that TTR plays a critical role in neurogenesis after irradiation, and allantoin and neferine could be potential drug candidates for recovering the effects of radiation on neurogenesis and depression.