Metabolic reprogramming is a malignancy hallmark, which refers to the ability of cancer cells to alter metabolic and nutrient acquisition modes in order to support the energy demands for accomplishing the rapid growth, dissemination, metastasis and obtain the "building blocks" needed to maintain cell division. When solid tumors are exposed to low pH, low oxygen and tumor microenvironment with nutrient deficiencies, the hypoxia-inducible factor-1 can be activated, which mediates the remodeling of metabolic patterns in tumor cells, namely, energy is obtained by circulating intracellular components (removing substrates such as proteins and lipid) or by utilizing adaptive metabolic reprogramming (such as glycolysis, autophagy and lipid metabolism, etc.). As a treatment scheme based on local heating of tumors, hyperthermia has a variety of anticancer mechanisms and can be used in combination with radiotherapy, chemotherapy and biological immune therapy. In this review, we briefly discussed the metabolic remodeling model mediated by hypoxia-inducible factor 1 in a hypoxia microenvironment, described the possible regulatory mechanism of hyperthermia on hypoxia-inducible factor-1 and prospected the application of hyperthermia in oral and maxillofacial tumors.

Objective:The investigate the roles and significance of HIF-1α and CYPJ in tongue squamous cell carcinoma cell (TSCC), and further evaluate the regulatory effect of hyperthermia (HT) on HIF-1α and CYPJ in TSCC cells.Methods:Eighty samples of cancer tissues and adjacent normal tissues from TSCC patients were collected. The expression levels of HIF-1α and CYPJ were detected by immunohistochemistry, Western blotting (WB) and fluorescence quantitative PCR, and the relationship between the expression levels of HIF-1α and CYPJ and clinicopathological characteristics was further analyzed. The expression levels of HIF-1α and CYPJ in Cal-27 cells under normoxic and hypoxic conditions for 24 h when combined with HT (42℃), chemotherapy and both were detected by qPCR and WB. Cell migration was detected by cell scratch test and cell apoptosis was measured by flow cytometry.Results:The expression levels of HIF-1α and CYPJ proteins in the tumor tissues of TSCC patients were higher than those in the adjacent normal tissues, which were significantly correlated with tumor size, TNM stage, differentiation degree and lymph node metastasis in TSCC patients (all P<0.05), whereas they were not correlated with gender or age (all P>0.05). The expression levels of HIF-1α and CYPJ in Cal-27 cells were significantly up-regulated in the hypoxic microenvironment (both P<0.05), which were also significantly enhanced by hyperthermia alone (both P<0.05). Compared with hyperthermia or chemotherapy alone, hyperthermia combined with chemotherapy significantly inhibited the expression of HIF-1α and CYPJ, suppressed cell migration and promoted cell apoptosis (all P<0.05). Conclusions:HIF-1α and CYPJ may be potential biomarkers for TSCC tumorigenicity and prognosis. In addition, tumor recurrence after hyperthermia may be due to the role of hyperthermia in triggering HIF-1α expression, which promotes the growth and survival of tumor cells adaptive to hyperthermia treatment by activating the downstream target genes, while hyperthermia combined with chemotherapy may be a promising treatment for TSCC.

In recent years, tumor hyperthermia has become a hot research topic as an adjuvant therapy to traditional tumor therapy. Hyperthermia can directly induce tumor cell necrosis or apoptosis, or inhibit tumor progression by destroying tumor blood vessels. Meantime, it can also activate the response of immune cells and cytokines in the immune system of the host, thereby regulating the immune state of tumor microenvironment. Multiple combined effects influence the tumor progression. A thorough understanding of the biological mechanism of hyperthermia is beneficial to the development of novel therapeutic methods. In this paper, the biological mechanism of hyperthermia in killing tumors was mainly reviewed.

Objective:To observe the effect of hyperthermia combined with paclitaxel on the proliferation, apoptosis and cycle of human tongue squamous cell carcinoma cell line CAL-27, and to explore the underlying mechanism.Methods:The working concentration of paclitaxel was determined by CCK-8 assay, and the cultured CAL-27 cells were divided into the control, paclitaxel, 42℃ hyperthermia and combined treatment groups. The ability of cell proliferation was detected by colony formation assay, and the cell cycle and apoptosis were determined by flow cytometry. The expression levels of AKT, p-AKT, Bcl-2 and Bax proteins in each group were measured by Western blot.Results:Compared with the control group, the proliferation was significantly inhibited and the apoptosis of CAL-27 cells was significantly promoted in the combined treatment, hyperthermia and paclitaxel groups (all P<0.05), and the anti-proliferation and apoptosis-promoting effect in the combined treatment group was significantly better than those in the hyperthermia and paclitaxel groups (all P<0.05). Western blot showed that hyperthermia combined with paclitaxel could significantly up-regulate the expression level of Bax protein and significantly down-regulate the expression levels of P-AKT and Bcl-2 in CAL-27 cells (all P<0.05). Conclusions:Hyperthermia combined with paclitaxel can play a synergistic role in inhibiting proliferation and promoting apoptosis of tongue squamous cell carcinoma CAL-27 cells. The mechanism may be related to the inhibition of AKT activation and the activation of Bax/Bcl-2 apoptosis signaling pathway.

Objective:To investigate the regulation and possible mechanism of hyperthermia (HT) on the ferroptosis of squamous cell carcinoma of the tongue cell line CAL-27.Methods:Half maximal inhibitory concentration (IC 50) of Fer-1, an inhibitor of ferroptosis, was detected by CCK-8 assay and used for subsequent experiments. CAL-27 cells were divided into the HT, control, Fer-1 and HT+ Fer-1 groups according to experimental design. Reactive oxygen species (ROS) levels and iron ion concentration were determined by corresponding detection kits. The p53 and TfR1 mRNA levels were detected by real-time reverse transcription PCR. Cell migration was detected by cell scratch test and cell apoptosis was detected by flow cytometry. Results:HT significantly up-regulated the ROS levels ( P<0.01) and iron ion concentration ( P<0.001), and significantly increased the expression levels of p53 and TfR1 mRNA (both P<0.01). The cell migration ability was decreased ( P<0.001), whereas cell apoptosis rate was increased by HT ( P<0.01). In the HT+Fer-1 group, the ROS levels ( P<0.001), iron ion concentration ( P<0.001), expression levels of p53 and TfR1 mRNA (both P<0.01) were significantly down-regulated, the cell migration ability was recovered ( P<0.01), and cell apoptosis rate was decreased ( P<0.01) compared with those in the HT group, respectively. Conclusions:HT may induce the ferroptosis of CAL-27 cell line, inhibit cell migration ability and promote cell apoptosis by activating the p53/TfR1 pathway.

Vascular endothelial growth factor (VEGF) plays an important role in promoting tumor vascular growth and changing vascular wall permeability. With the in-depth study of tumor hyperthermia and tumor microenvironment, more and more studies have shown that hyperthermia exerts multiple regulatory effects on VEGF in tumor microenvironment. Combined with current research progress in China and abroad, this article reviews the effect of hyperthermia on VEGF and its related cells and factors in tumor microenvironment, aiming to provide new ideas for the clinical application of tumor hyperthermia combined with immune or targeted therapy.

Tumor microenvironment possesses immunosuppression characteristics via the mechanism of inducing tumor cell immune escape. The interaction between tumor cells and tumor microenvironment is an important factor affecting tumor genesis and development. As an important part of tumor microenvironment, cancer-associated fibroblasts interact directly or indirectly with tumor cells and produce various cytokines to regulate tumor immune microenvironment. In recent years, hyperthermia has become an auxiliary means of anti-tumor therapy. With the development of research on tumor hyperthermia and tumor microenvironment, a large number of studies have found that hyperthermia can regulate cancer-associated fibroblasts in tumor microenvironment. In this article, recent research progresses of the effects of hyperthermia on cancer-associated fibroblasts and related cells and cytokines in tumor microenvironment were reviewed, providing a new way for clinical application of hyperthermia combined with immune or targeted therapy.

With the in-depth study of tumor hyperthermia and tumor immune microenvironment (TIME), the role of hyperthermia in TIME has captivated increasing attention from scholars in recent years. Based upon recent research progress at home and abroad, the effect and mechanism of hyperthermia on several major immune cells and immune-related cytokines in the TIME were reviewed in this article. Comprehensive and deep understanding of the regulation of hyperthermia on the TIME could provide new ideas and methods for tumor treatment.

【Objective】 Compare the early outcome and safety of endoscopy-unilateral laminectomy for bilateral decompression （Endo-ULBD） and posterior lumbar interbody fusion （PLIF） in the treatment of multi-segment lumbar central spinal stenosis. 【Methods】 We retrospectively analyzed 68 patients with multi-segment central lumbar spinal stenosis treated between October 2019 and October 2020 in the Department of Spine Surgery， Affiliated Hospital of Qingdao University. Of them 33 patients were treated with Endo-ULBD and 35 ones were treated with PLIF. We compared the operation time， times of intraoperative fluoroscopy， estimated intraoperative blood loss， incision length， postoperative time to get out of bed， postoperative hospital duration， complications， visual analogue scale （VAS）， Oswestry dysfunction index （ODI） score before and 1 day， 1 month， and 3 months after operation， Japanese Orthopedic Association Assessment Treatment Score （JOA）， and modified MacNab score 3 months after operation between the two groups of patients. 【Results】 Compared with PLIF group， Endo-ULBD group had significantly shorter operation time， smaller incision length， less intraoperative blood loss， shorter postoperative bed time and postoperative hospital stay， and fewer surgical complications （all P<0.05）. There was significantly more intraoperative fluoroscopy in Endo-ULBD group than in PLIF group （P<0.05）. The VAS， ODI and JOA scores of the two groups were significantly improved after treatment （P<0.05）. There was no statistical difference in VAS of leg pain between the two groups after treatment （P>0.05）. However， after treatment Endo-ULBD group outperformed PLIF group in lower back pain VAS， ODI， JOA and the 3-month follow-up excellent and good rates （P<0.05）. 【Conclusion】 For patients with multi-segment central lumbar spinal stenosis， Endo-ULBD treatment can achieve better early clinical outcome than PLIF surgery， with less bleeding， shorter operation time， faster postoperative recovery， and fewer complications.