Danshen is a common traditional Chinese medicine used to treat neoplastic and chronic inflammatory diseases in China. However, the effects of Danshen on human oral cancer cells remain relatively unknown. This study investigated the antiproliferative effects of a Danshen extract on human oral cancer SAS, SCC25, OEC-M1, and KB drug-resistant cell lines and elucidated the possible underlying mechanism. We investigated the anticancer potential of the Danshen extract in human oral cancer cell lines and an in vivo oral cancer xenograft mouse model. The expression of apoptosis-related molecules was evaluated through Western blotting, and the concentration of in vivo apoptotic markers was measured using immunohistochemical staining. The antitumor effects of 5-fluorouracil and the Danshen extract were compared. Cell proliferation assays revealed that the Danshen extract strongly inhibited oral cancer cell proliferation. Cell morphology studies revealed that the Danshen extract inhibited the growth of SAS, SCC25, and OEC-M1 cells by inducing apoptosis. The Flow cytometric analysis indicated that the Danshen extract induced cell cycle G0/G1 arrest. Immunoblotting analysis for the expression of active caspase-3 and X-linked inhibitor of apoptosis protein indicated that Danshen extract-induced apoptosis in human oral cancer SAS cells was mediated through the caspase pathway. Moreover, the Danshen extract significantly inhibited growth in the SAS xenograft mouse model. Furthermore, the Danshen extract circumvented drug resistance in KB drug-resistant oral cancer cells. The study results suggest that the Danshen extract could be a potential anticancer agent in oral cancer treatment.

The dysregulated expression of cyclin genes can lead to the uncontrolled proliferation of cancer cells. Histone demethylase Jumonji-C domain-containing protein 5 (KDM8, JMJD5) and cyclin A1 (CCNA1) are pivotal in cell cycle progression. A promising candidate for augmenting cancer treatment is Allyl isothiocyanate (AITC), a natural dietary chemotherapeutic and epigenetic modulator. This study aimed to investigate AITC’s impact on the KDM8/CCNA1 axis to elucidate its role in oral squamous cell carcinoma (OSCC) tumorigenesis. The expression of KDM8 and CCNA1 was assessed using a tissue microarray (TMA) immunohistochemistry (IHC) assay. In vitro experiments with OSCC cell lines and in vivo experiments with patient-derived tumor xenograft (PDTX) and SAS subcutaneous xenograft tumor models were conducted to explore AITC’s effects on their expression and cell proliferation. The results showed elevated KDM8 and CCNA1 levels in the OSCC patient samples. AITC exhibited inhibitory effects on OSCC tumor growth in vitro and in vivo. Additionally, AITC downregulated KDM8 and CCNA1 expression while inducing histone H3K36me2 expression in oral cancer cells. These findings underscore AITC’s remarkable anticancer properties against oral cancer, highlighting its potential as a therapeutic option for oral cancer treatment by disrupting the cell cycle by targeting the KDM8/CCNA1 axis.

MYC has a short half-life that is tightly regulated through phosphorylation and proteasomal degradation. Many studies have claimed that treatment with disulfiram (DSF) with or without copper ions can cause cancer cell death in a reactive oxygen species (ROS)-dependent manner in cancer cells. Our previous study showed that the levels of c-Myc protein and the phosphorylation of threonine 58 (T58) and serine 62 (S62) increased in DSF-Cu-complex-treated oral epidermoid carcinoma Meng-1 (OECM-1) cells. These abovementioned patterns were suppressed by pretreatment with an ROS scavenger, N-acetyl cysteine. The overexpression of c-Myc failed to induce hypoxia-inducible factor 1α protein expression, which was stabilized by the DSF-Cu complex. In this study, we further examined the regulatory mechanism behind the induction of the c-Myc of the DSF-Cu complex in an OECM-1 cell compared with a Smulow–Glickman (SG) human normal gingival epithelial cell. Our data showed that the downregulation of c-Myc truncated nick and p62 and the induction of the ratio of H3P/H3 and p-ERK/ERK might not be involved in the increase in the amount of c-Myc via the DSF/copper complexes in OECM-1 cells. Combined with the inhibitors for various signaling pathways and cycloheximde treatment, the increase in the amount of c-Myc with the DSF/copper complexes might be mediated through the increase in the stabilities of c-Myc (T58) and c-Myc (S62) proteins in OECM-1 cells. In SG cells, only the c-Myc (T58) protein was stabilized by the DSF-Cu (I and II) complexes. Hence, our findings could provide novel regulatory insights into the phosphorylation-dependent stability of c-Myc in DSF/copper-complex-treated oral squamous cell carcinoma.

Background: Okanin, a flavonoid compound derived from Bidens pilosa L., has garnered attention for its anti-inflammatory properties. Although Bidens pilosa is commonly used in healthcare products and functional foods, the anticancer potential of okanin, particularly in oral cancer, remains underexplored. This study aims to investigate the effects of okanin on oral cancer cell lines and its potential as a therapeutic agent. Methods: The study involved assessing the cytotoxic effects of okanin on oral cancer cell lines SAS, SCC25, HSC3, and OEC-M1. The IC50 values were determined using methylene blue assays, and the clonogenic capacity was evaluated through colony formation assays. Flow cytometry was used to analyze cell cycle progression and apoptosis. Caspase-3/7 activity assays and annexin V/7-AAD staining confirmed the induction of apoptosis and pyroptosis. In vivo efficacy was assessed using a SAS xenograft model, and immunohistochemical analysis of xenograft tissue was performed to examine pyroptosis-related markers. Results: Okanin exhibited potent cytotoxic effects with IC50 values of 12.0 ± 0.8, 58.9 ± 18.7, 18.1 ± 5.3, and 43.2 ± 6.2 μM in SAS, SCC25, HSC3, and OEC-M1 cells, respectively. It caused dose- and time-dependent reductions in cell viability and significantly impaired clonogenic capacity. Flow cytometry revealed G2/M cell cycle arrest and increased sub-G1 population, indicating cell cycle disruption and death. Okanin induced both apoptosis and pyroptosis, as confirmed by caspase-3/7 activity and annexin V/7-AAD staining. In vivo, okanin reduced tumor growth and involved pyroptosis-related markers such as CASP1, GSDMC, GSDMD, and GSDME. Conclusions: Okanin demonstrates significant anticancer potential, particularly in oral cancer, by inducing both apoptosis and pyroptosis. Its efficacy in reducing tumor growth in vivo further supports its potential as a novel therapeutic option. Further mechanistic studies are needed to elucidate the pathways involved in okanin-mediated cell death and to explore its clinical applications.

Background: Oral squamous cell carcinoma (OSCC) remains clinically challenging, particularly in advanced disease, where treatment resistance limits therapeutic outcomes. Ferroptosis, an iron-dependent form of regulated cell death driven by lipid peroxidation, has emerged as a potential anticancer vulnerability. Galectin-1 (Gal-1/LGALS1), a β-galactoside–binding lectin frequently overexpressed in OSCC, is associated with tumor progression and unfavorable prognosis; however, its involvement in ferroptosis regulation remains incompletely understood. Methods: To investigate whether Triptolide (TPL) influences ferroptosis-associated responses through Gal-1 modulation, OSCC cell lines (SAS and HSC-3) were treated with TPL and analyzed for cell viability, lipid reactive oxygen species (ROS) accumulation, and glutathione peroxidase 4 (GPX4) expression. Publicly available The Cancer Genome Atlas (TCGA) datasets were examined to evaluate Gal-1 expression patterns and survival associations. An OSCC xenograft mouse model was further used to assess the antitumor effects of TPL and changes in ferroptosis-related markers in vivo. Results: TPL treatment reduced cell viability and increased lipid ROS accumulation in OSCC cells, accompanied by downregulation of GPX4 expression. Gal-1 expression was also decreased following TPL exposure in vitro and in xenograft tumors. Analysis of TCGA data revealed that elevated Gal-1 expression was significantly associated with poorer overall survival in OSCC patients. Conclusions: These findings indicate that TPL induces ferroptosis-associated responses in OSCC and suggest that this effect is partly mediated through modulation of Gal-1 expression. Gal-1 may represent a clinically relevant factor influencing ferroptosis susceptibility, and targeting this pathway warrants further investigation as a potential therapeutic strategy for OSCC.

Salvinal is a natural lignan isolated from the roots of Salvia mitorrhiza Bunge (Danshen). Previous studies have demonstrated its anti-proliferative activity in both drug-sensitive and -resistant cancer cell lines, with IC₅₀ values ranging from 4–17 µM. In this study, a series of salvinal derivatives was synthesized and evaluated for the structure–activity relationship. Among the twenty-four salvinal derivatives, six compounds showed better anticancer activity than salvinal. Compound 25 displayed excellent anticancer activity, with IC₅₀ values of 0.13–0.14 µM against KB, KB-Vin10 (overexpress MDR/Pgp), and KB-7D (overexpress MRP) human carcinoma cell lines. Based on our in vitro microtubule depolymerization assay, compound 25 showed depolymerization activity in a dose-dependent manner. Our findings indicate that compound 25 is a promising anticancer agent with depolymerization activity that has potential for the management of malignance.