Synergistic Effect of Sorafenib and Radiation on Human Oral Carcinoma in vivo

A bibliometric analysis of programmed cell death in oral cancer literature: research patterns and emerging trends (2000-2024)

BACKGROUND

Programmed cell death (PCD) plays a crucial role in oral cancer pathogenesis and treatment. However, a comprehensive bibliometric analysis of the global research landscape in this field has not been conducted. This study aims to analyze the evolution and current trends of PCD research in oral cancer from 2000 to 2024.

METHODS

Publications were retrieved from the Web of Science Core Collection database using relevant keywords related to oral cancer and PCD. VOSviewer 1.6.20 and CiteSpace 6.1R6 software were employed to conduct bibliometric analysis, including publication trends, citation analysis, co-authorship networks, keyword co-occurrence, and research hotspots. The time span was set from January 2000 to December 2024.

RESULTS

A total of 963 publications were identified and analyzed. The annual publication output showed a steady increase, with a significant growth rate after 2010, dividing the study period into three distinct phases. The most productive countries were China (58.42%), South Korea (12.27%), and Japan (10.04%), with China Medical University and Kaohsiung Medical University being the leading institutions. Research hotspots evolved from traditional apoptosis studies to emerging forms of PCD such as autophagy, ferroptosis, and pyroptosis. Keyword analysis revealed three major research clusters: basic molecular mechanisms (centered around ROS and oxidative stress), clinical aspects (including prognosis and cell proliferation), and cell death pathways. Citation burst analysis identified emerging trends in targeting multiple PCD pathways simultaneously for oral cancer therapy, with special focus on treatment resistance and survival.

CONCLUSION

This bibliometric analysis provides a comprehensive overview of global research trends in PCD and oral cancer over the past two decades. The findings highlight the shift from basic mechanistic studies focusing on apoptosis to more diverse PCD pathways and translational research. Emerging research directions include the exploration of synergistic mechanisms among multiple PCD pathways, development of AI-based personalized treatment plans, investigation of microenvironment regulation of PCD, and application of novel drug delivery systems. These trends demonstrate the field's evolution toward more integrated, personalized approaches in oral cancer treatment. This study offers valuable insights for researchers and funding agencies to identify research gaps and potential collaboration opportunities in this rapidly developing field.

Biological consequences of cancer radiotherapy in the context of oral squamous cell carcinoma

Approximately 50% of subjects with cancer have been treated with ionizing radiation (IR) either as a curative, adjuvant, neoadjuvant or as a palliative agent, at some point during the clinical course of their disease. IR kills cancer cells directly by injuring their DNA, and indirectly by inducing immunogenic cell killing mediated by cytotoxic T cells; but it can also induce harmful biological responses to non-irradiated neighbouring cells (bystander effect) and to more distant cells (abscopal effect) outside the primary tumour field of irradiation.Although IR can upregulate anti-tumour immune reactions, it can also promote an immunosuppressive tumour microenvironment. Consequently, radiotherapy by itself is seldom sufficient to generate an effective long lasting immune response that is capable to control growth of metastasis, recurrence of primary tumours and development of second primary cancers. Therefore, combining radiotherapy with the use of immunoadjuvants such as immune checkpoint inhibitors, can potentiate IR-mediated anti-tumour immune reactions, bringing about a synergic immunogenic cell killing effect.The purpose of this narrative review is to discuss some aspects of IR-induced biological responses, including factors that contributes to tumour radiosensitivity/radioresistance, immunogenic cell killing, and the abscopal effect.

Sorafenib for hepatocellular carcinoma: potential molecular targets and resistance mechanisms

Hepatocellular carcinoma (HCC) is the most widespread typical therapy-resistant, unresectable type of malignant solid tumour with a high death rate constituting huge medical concern. Sorafenib is a small molecule oral multi-target kinase potent inhibitor that acts by suppressing/blocking the multiplication of the tumour cells, angiogenesis, and encouraging apoptosis of the tumour cells. Though, the precise mechanism of tumour cell death induction by sorafenib is yet under exploration. Furthermore, genetic heterogeneity plays a critical role in developing sorafenib resistance, which leads the way to identify the need for predictive biomarkers responsible for drug resistance. Therefore, it is essential to find out the fundamental resistance mechanisms to expand therapeutic plans. The authors summarize the molecular concepts of resistance, progression, potential molecular targets, HCC management therapies, and discussion on the advancements expected in the coming future, inclusive of biomarker-driven treatment strategies, which may provide the prospects to design innovative therapeutically targeted strategies for the HCC treatment and the clinical implementation of emerging targeted agents.

Effects of orlistat combined with enzalutamide and castration through inhibition of fatty acid synthase in a PC3 tumor-bearing mouse model

Androgen deprivation therapy (ADT) is one of the typical treatments used for patients with prostate cancer (PCa). ADT, however, may fail when PCa develops castration-resistance. Fatty acid synthase (FASN), a critical enzyme involved in fatty acid synthesis, is found to be up-regulated in PCa. Since enzalutamide and ADT are frequently used for the treatment of PCa, the present study aimed to unravel the underlying mechanism of combination of orlistat, an FASN inhibitor, and enzalutamide using PC3 cell line; and orlistat and castration in PC3 tumor-bearing animal model. Cytotoxicity was determined by AlamarBlue assay. Drug effects on the cell cycle and protein expressions were assayed by the flow cytometry and Western blot. Electromobility shift assay was used to evaluate the NF-κB activity. The tumor growth delay, expressions of the signaling-related proteins, and histopathology post treatments of orlistat and castration were evaluated in PC3 tumor-bearing mouse model. The results showed that orlistat arrested the PC3 cells at the G₁ phase of the cell cycle and enhanced the cytotoxic effects of enzalutamide synergistically. Pretreatment with orlistat combined with castration inhibited the tumor growth significantly compared with those of castration and orlistat treatments alone in PC3 tumor-bearing mice. Combination treatment reduced both FASN and NF-κB activities and their downstream effector proteins. The present study demonstrated the synergistic effects of orlistat combined with enzalutamide in vitro and castration in vivo on human PCa.

A combination of sorafenib and radiotherapy reduces NF-κB activity and growth of hepatocellular carcinoma in an orthotopic mouse model

Hepatocellular carcinoma (HCC) is difficult to diagnose at an early stage, and its prognosis is generally poor. Sorafenib is the primary treatment for unresectable advanced HCC and targets multiple receptor tyrosine kinases. However, sorafenib only extends the average survival time by 3 months. This observation indicates that sorafenib may need to be combined with other treatments to further improve outcomes. We previously showed that combination of sorafenib with radiotherapy (RT) enhances tumor inhibition in subcutaneous HCC mouse models compared with monotherapy. The present study demonstrated that combining sorafenib and RT could suppress tumor growth in an orthotopic HCC model by regulating apoptosis and NF-κB-related pathways. Moreover, decreased numbers of visible liver tumors and a smaller percentage of spleen metastases were found in the combination group. A transient drop in body weight was initially observed after RT, but progressive recovery of body weight occurred. The current study showed that the combination of sorafenib and RT could be a safe strategy for HCC treatment.

The Application of Next-Generation Sequencing to Define Factors Related to Oral Cancer and Discover Novel Biomarkers

Despite the introduction of next-generation sequencing in the realm of DNA sequencing technology, it is not often used in the investigation of oral squamous cell carcinoma (OSCC). Oral cancer is one of the most frequently occurring malignancies in some parts of the world and has a high mortality rate. Patients with this malignancy are likely to have a poor prognosis and may suffer from severe facial deformity or mastication problems even after successful treatment. Therefore, a thorough understanding of this malignancy is essential to prevent and treat it. This review sought to highlight the contributions of next-generation sequencing (NGS) in unveiling the genetic alterations and differential expressions of miRNAs involved in OSCC progression. By applying an appropriate eligibility criterion, we selected relevant studies for review. Frequently identified mutations in genes such as TP53, NOTCH1, and PIK3CA are discussed. The findings of existing miRNAs (e.g., miR-21) as well as novel discoveries pertaining to OSCC are also covered. Lastly, we briefly mention the latest findings in targeted gene therapy and the potential use of miRNAs as biomarkers. Our goal is to encourage researchers to further adopt NGS in their studies and give an overview of the latest findings of OSCC treatment.

Anlotinib is effective in patients with advanced oral cancer?

Oral cancer patients with recurrence or distant metastasis often present poor prognosis. Majority of advanced oral cancer patients suffer from treat-related adverse events and drug resistance. For those patients, the survival time and quality of life are urgent to be improved. Anlotinib, as a multi-targets tyrosine kinase inhibitor (TKI), has been demonstrated to be effective in many refractory tumors by inhibiting tumor angiogenesis and partial functions of tumor cells. In this paper, we performed CCK-8 assay, wound healing assay and transwell assay to explore the effect of anlotinib on human tongue squamous carcinoma Tca8113 cell line. Preliminary data indicated that anlotinib significantly inhibited Tca8113 cells proliferation, migration and invasion in vitro. Together, we proposed a hypothesis that anlotinib might be effective in prolonging survival time of patients with advanced oral cancer.

Fatty Acid Inhibition Sensitizes Androgen-Dependent and -Independent Prostate Cancer to Radiotherapy via FASN/NF-κB Pathway

Elevated fatty acid synthase (FASN) has been reported in both androgen-dependent and -independent prostate cancers. Conventional treatment for prostate cancer is radiotherapy (RT); however, the following radiation-induced radioresistance often causes treatment failure. Upstream proteins of FASN such as Akt and NF-κB are found increased in the radioresistant prostate cancer cells. Nevertheless, whether inhibition of FASN could improve RT outcomes and reverse radiosensitivity of prostate cancer cells is still unknown. Here, we hypothesised that orlistat, a FASN inhibitor, could improve RT outcomes in prostate cancer. Orlistat treatment significantly reduced the S phase population in both androgen-dependent and -independent prostate cancer cells. Combination of orlistat and RT significantly decreased NF-κB activity and related downstream proteins in both prostate cancer cells. Combination effect of orlistat and RT was further investigated in both LNCaP and PC3 tumour-bearing mice. Combination treatment showed the best tumour inhibition compared to that of orlistat alone or RT alone. These results suggest that prostate cancer treated by conventional RT could be improved by orlistat via inhibition of FASN.

Benzyl isothiocyanate inhibits human brain glioblastoma multiforme GBM 8401 cell xenograft tumor in nude mice in vivo

Benzyl isothiocyanate (BITC), a member of isothiocyanates (ITCs), has been shown to induce cell death in many human cancer cells, but there is no further report to show BITC suppresses glioblastoma multiforme cells in vivo. In the present study, we investigate the effects of BITC on the inhibition of GBM 8401/luc2 cell generated tumor on athymic nude mice. We established a luciferase expressing stable clone named as GBM 8401/luc2. Thirty male mice were inoculated subcutaneously with GBM 8401/luc2 cells to generate xenograft tumor mice model. Group I was treated with 110 μL phosphate-buffered solution plus 10 μL dimethyl sulfoxide, Group II-III with BITC (5 or 10 μmol/100 μL/day, relatively). Mice were given oral treatment of BITC by gavage for 21 days. Results showed that BITC did not affect the body weights. After anesthetized, the photons emitted from mice tumor were detected with Xenogen IVIS imaging system 200 and higher dose of BITC have low total photon flux than that of lower dose of BITC. Results also showed that higher dose of BITC have low total tumor volumes and weights than that of low dose of BITC. Isolated tumors were investigated by immunohistochemical analysis and results showed that BITC at both dose of treatment weakly stained with anti-MCL1 and -XIAP. However, both dose of BITC treatments have strong signals of caspase-3 and Bax. Overall, these data demonstrated that BITC suppressed tumor properties in vivo. Overall, based on these observations, BITC can be used against human glioblastoma multiforme in the future.

Phenethyl Isothiocyanate Inhibits In Vivo Growth of Xenograft Tumors of Human Glioblastoma Cells

Phenethyl isothiocyanate (PEITC) from cruciferous vegetables can inhibit the growth of various human cancer cells. In previous studies, we determined that PEITC inhibited the in vitro growth of human glioblastoma GBM 8401 cells by inducing apoptosis, inhibiting migration and invasion, and altering gene expression. Nevertheless, there are no further in vivo reports disclosing whether PEITC can suppress the growth of glioblastoma. Therefore, in this study we investigate the anti-tumor effects of PEITC in a xenograft model of glioblastoma in nude mice. Thirty nude mice were inoculated subcutaneously with GBM 8401 cells. Mice with one palpable tumor were divided randomly into three groups: control, PEITC-10, and PEITC-20 groups treated with 0.1% dimethyl sulfoxide (DMSO), and 10 and 20 μmole PEITC/100 μL PBS daily by oral gavage, respectively. PEITC significantly decreased tumor weights and volumes of GBM 8401 cells in mice, but did not affect the total body weights of mice. PEITC diminished the levels of anti-apoptotic proteins MCL-1 (myeloid cell leukemia 1) and XIAP (X-linked inhibitor of apoptosis protein) in GBM 8401 cells. PEITC enhanced the levels of caspase-3 and Bax in GBM 8401 cells. The growth of glioblastoma can be suppressed by the biological properties of PEITC in vivo. These effects might support further investigations into the potential use of PEITC as an anticancer drug for glioblastoma.

Synergistic effects of tetrandrine combined with ionizing radiation on a murine colorectal carcinoma‑bearing mouse model

Tetrandrine (TET), a traditional Chinese clinical agent, has been used for the treatment of many diseases, including cancers. The purpose of the present study was to investigate the combined effects of TET and ionizing radiation (IR) on murine CT26 colorectal adenocarcinoma cells in vitro and in vivo. A CT26 cell line transfected with dual HSV-1 thymidine kinase and firefly luciferase (luc) reporter genes was used. The half-maximal inhibitory concentration (IC₅₀) of TET in CT26/tk-luc cells was ~10 µM. An additive effect was observed after combination of both agents based on a colony formation assay. Apoptosis and cleaved caspase-3 levels were increased significantly in cells after combination treatment, as shown by flow cytometric analysis, DNA fragmentation and western blotting. However, tumor growth inhibition and therapeutic efficacy of TET combined with IR in vivo were identified to be synergistic, as monitored by tumor growth delay time, measured with a digital caliper. A significant inhibition of tumor growth was identified in the combination group compared with the radiation only group. Furthermore, non-invasive bioluminescent imaging (BLI) and gamma scintigraphy were also used to evaluate therapeutic efficacy. Both modalities revealed that the best tumor growth control was under combination treatment among all groups. The present study demonstrated that TET is not only beneficial for chemotherapy, but also has potential as a radiosensitizer for the treatment of cancer.

Mutant monocyte chemoattractant protein-1 protein (7ND) inhibits osteoclast differentiation and reduces oral squamous carcinoma cell bone invasion

The seven-amino acid truncated (7ND) protein is an N-terminal deletion mutant of monocyte chemoattractant protein-1 (MCP-1) and it functions as a dominant-negative inhibitor. 7ND and wild-type MCP-1 form a heterodimer, which binds to MCP-1 receptors and inhibits monocyte chemotaxis. In the present study, the 7ND protein was cloned, expressed and purified. An MTT assay revealed that the proliferation of oral squamous cell carcinoma (OSCC) SCC25 cells was not affected following 3 days of treatment with synthetic 7ND protein. Serial dilutions of the 7ND protein were tested for monocyte migration and osteoclast differentiation, and tartrate-resistant acid phosphatase staining demonstrated that significantly fewer osteoclasts were differentiated from cluster of differentiation 14⁺ (CD14⁺) monocytes using magnetic activated cell sorting. Immunofluorescence confirmed these results and significantly less F-actin staining was observed in 7ND-treated osteoclasts. Furthermore, bone invasion was examined by subcutaneously injecting SCC25 cells into the area overlaying the calvariae of nude mice. The results demonstrated that the average tumor volume of SCC25 cells with 7ND protein was similar to the average volume of tumors formed by untreated SCC25 cells. Flow cytometric analysis suggested that the CD14⁺ subpopulation in the bone marrow of 7ND-treated mice was reduced compared with that of untreated mice. Micro-computed tomography imaging revealed significantly less bone resorption in the calvariae injected with SCC25 cells plus the 7ND protein. Taken together, the results of the present study demonstrated the potential therapeutic value of the 7ND protein. The 7ND MCP-1 variant not only functions in vitro to inhibit osteoclast differentiation, but also reduces the progression of bone invasion by OSCC cells in vivo.

Sorafenib pretreatment enhances radiotherapy through targeting MEK/ERK/NF-κB pathway in human hepatocellular carcinoma-bearing mouse model

Patients with unresectable hepatocellular carcinoma (HCC) usually have poor prognosis because current monotherapy including surgery, chemotherapy and radiotherapy (RT) are not effective. Combination therapy may be effective to overcome this clinical problem. Here, we proposed the combination of sorafenib and RT, which have been applied in HCC treatment, could improve the treatment outcome of HCC. Our previous study showed that sorafenib could suppress the expression of NF-κB which is related to the chemo- and radio-resistance. Nevertheless, the expression of NF-κB is oscillatory and is affected by the treatments. Thus, understanding the oscillation of NF-κB expression would be beneficial for determining the optimal treatment schedule in combination therapy. Here established Huh7/NF-κB-tk-luc2/rfp cell line, in which NF-κB indicates a NF-κB promoter, was utilized to noninvasively monitor the expression of NF-κB overtime in vitro and in vivo. The results show that pretreatment of sorafenib with RT suppresses the expressions of NF-κB and its downstream proteins induced by radiation through downregulation of phosphorylated extracellular signal-regulated kinase (pERK) most significantly compared with other treatment schedules. The results were further verified with Western blotting, EMSA, and NF-κB molecular imaging. These findings suggest that pretreatment of sorafenib with RT may be the ideal treatment schedule for the treatment of HCC.

Podoplanin emerges as a functionally relevant oral cancer biomarker and therapeutic target

Oral cancer has become one of the most aggressive types of cancer, killing 140,000 people worldwide every year. Current treatments for oral cancer include surgery and radiation therapies. These procedures can be very effective; however, they can also drastically decrease the quality of life for survivors. New chemotherapeutic treatments are needed to more effectively combat oral cancer. The transmembrane receptor podoplanin (PDPN) has emerged as a functionally relevant oral cancer biomarker and chemotherapeutic target. PDPN expression promotes tumor cell migration leading to oral cancer invasion and metastasis. Here, we describe the role of PDPN in oral squamous cell carcinoma progression, and how it may be exploited to prevent and treat oral cancer.

MALDI imaging reveals NCOA7 as a potential biomarker in oral squamous cell carcinoma arising from oral submucous fibrosis

Oral squamous cell carcinoma (OSCC) ranks among the most common cancer worldwide, and is associated with severe morbidity and high mortality. Oral submucous fibrosis (OSF), characterized by fibrosis of the mucosa of the upper digestive tract, is a pre-malignant lesion, but the molecular mechanisms underlying this malignant transformation remains to be elucidated. In this study, matrix-assisted laser desorption ionization imaging mass spectrometry (MALDI-IMS)-based proteomic strategy was employed to profile the differentially expressed peptides/proteins between OSCC tissues and the corresponding adjacent non-cancerous OSF tissues. Sixty-five unique peptide peaks and nine proteins were identified with altered expression levels. Of them, expression of NCOA7 was found to be up-regulated in OSCC tissues by immunohistochemistry staining and western blotting, and correlated with a pan of clinicopathologic parameters, including lesion site, tumor differentiation status and lymph node metastasis. Further, we show that overexpression of NCOA7 promotes OSCC cell proliferation in either in vitro or in vivo models. Mechanistic study demonstrates that NCOA7 induces OSCC cell proliferation probably by activating aryl hydrocarbon receptor (AHR). The present study suggests that NCOA7 is a potential biomarker for early diagnosis of OSF malignant transformation, and leads to a better understanding of the molecular mechanisms responsible for OSCC development.

Intracellular interactions of electrostatically mediated layer-by-layer assembled polyelectrolytes based sorafenib nanoparticles in oral cancer cells

In this paper, we report the preparation of LbL-nanoSraf (100-300nm) comprising of layer-by-layer (LbL) assembled polyelectrolytes dextran-sulfate/poly-l-arginine, with a multikinase inhibitor sorafenib (Sraf) encapsulated calcium carbonate (CaCO3) nanoparticles for oral cancer therapy in vitro. The zeta potential of LbL-nanoSraf exhibited a negative charge of the polyanionic dextran sulfate, which alternated with a positive charge of polycationic poly-l-arginine indicating a successful LbL assembly of the two polyelectrolyte bilayers on the CaCO3 nanoparticles. The LbL-nanoSraf exhibited an encapsulation efficiency of 61±4%. The LbL-nanoSraf was characterized using field-emission gun scanning electron microscopy, X-ray powder diffraction, atomic force microscopy and confocal laser scanning microscopy. Confocal laser scanning microscopy, flow cytometry and transmission electron microscopic investigations showed the internalization of LbL-nanoSraf in human oral cancer (KB) cells. The LbL-nanoSraf exhibited more potent antiproliferative, apoptotic and antimigratory activities in KB cells than the free drug Sraf. The findings could promote the application of nano-sized LbL assembled polyelectrolytes for the delivery of Raf-kinase inhibitors and provide mechanistic insights for oral cancer therapy.