FLLL32 Triggers Caspase-Mediated Apoptotic Cell Death in Human Oral Cancer Cells by Regulating the p38 Pathway

A Thia-Analogous Indirubin N-Glycoside Disrupts Mitochondrial Function and Causes the Death of Human Melanoma and Cutaneous Squamous Cell Carcinoma Cells

Skin cancer is the most common malignant disease worldwide and, therefore, also poses a challenge from a pharmacotherapeutic perspective. Derivatives of indirubin are an interesting option in this context. In the present study, the effects of 3-[3'-oxo-benzo[b]thiophen-2'-(Z)-ylidene]-1-(β-d-glucopyranosyl)-oxindole (KD87), a thia-analogous indirubin N-glycoside, on the viability and mitochondrial properties of melanoma (A375) and squamous cell carcinoma cells (A431) of the skin were investigated. In both cell lines, KD87 caused decreased viability, the activation of caspases-3 and -7, and the inhibition of colony formation. At the mitochondrial level, a concentration-dependent decrease in both the basal and ATP-linked oxygen consumption rate and in the reserve capacity of oxidative respiration were registered in the presence of KD87. These changes were accompanied by morphological alterations in the mitochondria, a release of mitochondrial cytochrome c into the cytosol and significant reductions in succinate dehydrogenase complex subunit B (SDHB, subunit of complex II) in A375 and A431 cells and NADH:ubiquinone oxidoreductase subunit B8 (NDUFB8, subunit of complex I) in A375 cells. The effect of KD87 was accompanied by a significant upregulation of the enzyme heme oxygenase-1, whose inhibition led to a partial but significant reduction in the metabolic-activity-reducing effect of KD87. In summary, our data show a mitochondria-targeting effect of KD87 as part of the cytotoxic effect of this compound on skin cancer cells, which should be considered in future studies with this class of compounds.

Curcumin and analogues against head and neck cancer: From drug delivery to molecular mechanisms

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) is one of the most life-threatening diseases which also causes economic burden worldwide. To overcome the limitations of traditional therapies, investigation into alternative adjuvant treatments is crucial.

PURPOSE

Curcumin, a turmeric-derived compound, demonstrates significant therapeutic potential in diverse diseases, including cancer. Furthermore, research focuses on curcumin analogues and novel drug delivery systems, offering approaches for improved efficacy. This review aims to provide a comprehensive overview of curcumin's current findings, emphasizing its mechanisms of anti-HNSCC effects and potential for clinical application.

METHOD

An electronic search of Web of Science, MEDLINE, and Embase was conducted to identify literature about the application of curcumin or analogues in HNSCC. Titles and abstracts were screened to identify potentially eligible studies. Full-text articles will be obtained and independently evaluated by two authors to make the decision of inclusion in the review.

RESULTS

Curcumin's clinical application is hindered by poor bioavailability, prompting the exploration of methods to enhance it, such as curcumin analogues and novel drug delivery systems. Curcumin could exhibit anti-cancer effects by targeting cancer cells and modulating the tumor microenvironment in HNSCC. Mechanisms of action include cell cycle arrest, apoptosis promotion, reactive oxygen species induction, endoplasmic reticulum stress, inhibition of epithelial-mesenchymal transition, attenuation of extracellular matrix degradation, and modulation of tumor metabolism in HNSCC cells. Curcumin also targets various components of the tumor microenvironment, including cancer-associated fibroblasts, innate and adaptive immunity, and lymphovascular niches. Furthermore, curcumin enhances the anti-cancer effects of other drugs as adjunctive therapy. Two clinical trials report its potential clinical applications in treating HNSCC.

CONCLUSION

Curcumin has demonstrated therapeutic potential in HNSCC through in vitro and in vivo studies. Its effectiveness is attributed to its ability to modulate cancer cells and interact with the intricate tumor microenvironment. The development of curcumin analogues and novel drug delivery systems has shown promise in improving its bioavailability, thereby expanding its clinical applications. Further research and exploration in this area hold great potential for harnessing the full therapeutic benefits of curcumin in HNSCC treatment.

Apoptotic effect and cell arrest of deoxyshikonin in human osteosarcoma cells through the p38 pathway

Osteosarcoma is the most common primary bone cancer that affects adolescents with early metastatic potential and drastically reduces their long-term survival rate if pulmonary metastases are detected at diagnosis. The natural naphthoquinol compound deoxyshikonin exhibits anticancer properties, so we hypothesized that it has an apoptotic effect on osteosarcoma U2OS and HOS cells and studied its mechanisms. After deoxyshikonin treatment, dose-dependent decreases in cell viability, induction of cell apoptosis and arrest in the sub-G1 phase of U2OS and HOS cells were observed. The increases in cleaved caspase 3 expression and the decreases in X-chromosome-linked IAP (XIAP) and cellular inhibitors of apoptosis 1 (cIAP-1) expressions after deoxyshikonin treatment in the human apoptosis array were identified in HOS cells, and dose-dependent expression changes of IAPs and cleaved caspase 3, 8 and 9 were verified by Western blotting in U2OS and HOS cells. Phosphorylation of extracellular signal-regulated protein kinases (ERK)1/2, c-Jun N-terminal kinases (JNK)1/2 and p38 expressions in U2OS and HOS cells was also increased by deoxyshikonin in a dose-dependent manner. Subsequently, cotreatment with inhibitors of ERK (U0126), JNK (JNK-IN-8) and p38 (SB203580) was performed to show that p38 signalling is responsible for deoxyshikonin-induced apoptosis in U2OS and HOS cells, but not via the ERK and JNK pathways. These discoveries demonstrate that deoxyshikonin may be a possible chemotherapeutic candidate to induce cell arrest and apoptosis by activating extrinsic and intrinsic pathways through p38 for human osteosarcoma.

Hispolon induces apoptosis in oral squamous cell carcinoma cells through JNK / HO ‐1 pathway activation

Oral squamous cell carcinoma (OSCC) has a high recurrence rate and poor prognosis. Hispolon, a polyphenolic compound with antiviral, antioxidant, and anticancer activities, is a potential chemotherapy agent. However, few studies have investigated the anti-cancer mechanism of hispolon in oral cancer. This present study used the cell viability assay, clonogenic assay, fluorescent nuclear staining, and flow cytometry assay to analyse the apoptosis-inducing effects of hispolon in OSCC cells. After hispolon treatment, the apoptotic initiators, cleaved caspase-3, -8, and - 9, were upregulated, whereas the cellular inhibitor of apoptosis protein-1 (cIAP1) was downregulated. Furthermore, a proteome profile analysis using a human apoptosis array revealed the overexpression of heme oxygenase-1 (HO-1) by hispolon, which was determined to be involved in caspase-dependent apoptosis. Moreover, cotreatment with hispolon and mitogen-activated protein kinase (MAPK) inhibitors revealed that hispolon induces apoptosis in OSCC cells through activation of the c-Jun N-terminal kinase (JNK) pathway and not the extracellular signal-regulated kinase (ERK) or p38 pathway. These findings indicate that hispolon may exert an anticancer effect on oral cancer cells by upregulating HO-1 and inducing caspase-dependent apoptosis by activating the JNK pathway.

EF-24 inhibits TPA-induced cellular migration and MMP-9 expression through the p38 signaling pathway in cervical cancer cells

Diphenyl difluoroketone (EF-24), a synthetic curcumin analog, has enhanced bioavailability over curcumin. EF-24 acts more powerful bioactivity for anti-inflammatory and anti-cancer activity. However, the effects and mechanism of EF-24 on cervical cancer has not been fully investigated. Herein, this study evaluated the effects of EF-24 on TPA-induced cellular migration of cervical cancer. The results showed that EF-24 substantially reduced the cellular migration and cellular invasion of the HeLa and SiHa cells. Moreover, gelatin zymography, western blotting analyses and real-time PCR revealed that EF-24 suppressed Matrix metalloproteinase-9 (MMP-9) activity, protein expression and mRNA levels. Mechanistically, EF-24 inhibited the phosphorylation of the p38 signaling pathway. In conclusion, EF-24 inhibited TPA-induced cellular migration and cellular invasion of cervical cancer cell lines through modulating MMP-9 expression via downregulating signaling p38 pathway and EF-24 may have potential to serve as a chemopreventive agent of cervical cancer.

CLEFMA induces intrinsic and extrinsic apoptotic pathways through ERK1/2 and p38 signalling in uterine cervical cancer cells

Although concurrent chemoradiotherapy is the cornerstone of treatment for locally advanced or recurrent uterine cervical cancer, treatment fails at a high rate. Therefore, the development of novel targeting agents is critical. This study investigated the action of CLEFMA, a potent, synthetic curcumin derivative, on cervical cancer cells and its mechanism of action. We found that CLEFMA negatively regulated the viability of cervical cancer cells, involving induction of cell apoptosis. Cleaved caspase-3, cleaved poly(adenosine diphosphate-ribose) polymerase, cleaved caspase-8, and cleaved caspase-9 expression were increased by treatment with CLEFMA. After U0126 (ERK1/2 inhibitor) and SB203580 (p38 inhibitor) were applied as cotreatment with CLEFMA, the expression of cleaved caspase-8, -9, and -3 was reduced significantly. In conclusion, CLEFMA activates both extrinsic and intrinsic apoptotic pathways through ERK1/2 and p38 signal transduction in cervical cancer cells.

CLEFMA Induces the Apoptosis of Oral Squamous Carcinoma Cells through the Regulation of the P38/HO-1 Signalling Pathway

The purpose of this research was to evaluate the impact and the underlying molecular mechanism of CLEFMA-induced cell death in human OSCC. The anti-tumour properties of CLEFMA in oral cancer were explored using colony formation, flow cytometry, human apoptosis array, Western blot, and immunohistochemistry assays. The in vivo anti-tumour effect of CLEFMA administered by oral gavage was evaluated using SCC-9-derived xenograft-bearing nude mouse models. CLEFMA significantly suppressed colony formation and elicited cellular apoptosis in oral cancer cells. CLEFMA treatment remarkably increased phosphorylated p38 and HO-1 along with cleavage of poly ADP-ribose polymerase and activation of caspase-8, -9, and -3 in HSC-3 and SCC-9 cells. Administration of HO-1 small interfering RNA significantly protected the cells from CLEFMA-induced caspase-3, -8, and -9 activation. Attenuation of p38 activity by the pharmacologic inhibitor SB203580 dramatically reduced CLEFMA-induced caspase-3, -8, and -9 activation and HO-1 expression in OSCC. The subcutaneous murine xenograft models showed that CLEFMA in vivo suppressed tumour growth in implanted SCC-9 cells. All of these findings indicated that CLEFMA induced apoptosis through the p38-dependent rise in HO-1 signal transduction cascades in OSCC.

Hemoxygenase-1 Promotes Head and Neck Cancer Cell Viability

Head and neck squamous cell carcinoma (HNSCC) is a remarkably heterogeneous disease with around 50% mortality, a fact that has prompted researchers to try new approaches to improve patient survival. Hemoxygenase-1 (HO-1) is the rate-limiting step for heme degradation into carbon monoxide, free iron and biliverdin. We have previously reported that HO-1 protein is upregulated in human HNSCC samples and that it is localized in the cytoplasmic and nuclear compartments; additionally, we have demonstrated that HO-1 nuclear localization is associated with malignant progression. In this work, by using pharmacological and genetic experimental approaches, we begin to elucidate the mechanisms through which HO-1 plays a role in HNSCC. We found that high HO-1 mRNA was associated with decreased patient survival in early stages of HNSCC. In vitro experiments have shown that full-length HO-1 localizes in the cytoplasm, and that, depending on its enzymatic activity, it increases cell viability and promotes cell cycle progression. Instead, HO-1 does not alter migration capacity. Furthermore, we show that C-terminal truncated HO-1 localizes into the nucleus, increases cell viability and promotes cell cycle progression. In conclusion, we herein demonstrate that HO-1 displays protumor activities in HNSCC that depend, at least in part, on the nuclear localization of HO-1.

Transgelin-2 Involves in the Apoptosis of Colorectal Cancer Cells Induced by Tanshinone-IIA

Tanshinone IIA (TanIIA) is the main active ingredient in the fat-soluble components isolated from Salvia miltiorrhiza Bunge. Our previous studies have convincingly proved that TanIIA is an effective drug against human colorectal carcinoma cells. In order to further demonstrate the effect of TanIIA on CRC, we carried out exploratory research about it in vivo and in vitro. The results demonstrated that TanIIA were observably more effective than control group in preventing tumor growth, and it has increased the survival time. Cancer cells viability and proliferation were accompanied by concentration and time dependent decline reached with TanIIA. We found that TanIIA altered the morphology of cytoskeleton and it could obviously induce apoptosis of colorectal cancer cells and block the cells in the G0/G1 phase. TanIIA also increased phosphorylation of p38MAPK, upregulated ATF-2 expression and downregulated Transgelin-2 expression, which could be reversed by SB203580, a p38MAPK-specific inhibitor. Our results suggested that TanIIA could induce apoptosis of colorectal cancer and block the cells in G0/G1 phase involved in downregulating the expression of Transgelin-2 through p38MAPK signal pathway.

Curcuminoids as Modulators of EMT in Invasive Cancers: A Review of Molecular Targets With the Contribution of Malignant Mesothelioma Studies

Curcuminoids, which include natural acyclic diarylheptanoids and the synthetic analogs of curcumin, have considerable potential for fighting against all the characteristics of invasive cancers. The epithelial-to-mesenchymal transition (EMT) is a fundamental process for embryonic morphogenesis, however, the last decade has confirmed it orchestrates many features of cancer invasiveness, such as tumor cell stemness, metabolic rewiring, and drug resistance. A wealth of studies has revealed EMT in cancer is in fact driven by an increasing number of parameters, and thus understanding its complexity has now become a cornerstone for defining future therapeutic strategies dealing with cancer progression and metastasis. A specificity of curcuminoids is their ability to target multiple molecular targets, modulate several signaling pathways, modify tumor microenvironments and enhance the host’s immune response. Although the effects of curcumin on these various parameters have been the subject of many reviews, the role of curcuminoids against EMT in the context of cancer have never been reviewed so far. This review first provides an updated overview of all EMT drivers, including signaling pathways, transcription factors, non-coding RNAs (ncRNAs) and tumor microenvironment components, with a special focus on the most recent findings. Secondly, for each of these drivers the effects of curcumin/curcuminoids on specific molecular targets are analyzed. Finally, we address some common findings observed between data reported in the literature and the results of investigations we conducted on experimental malignant mesothelioma, a model of invasive cancer representing a useful tool for studies on EMT and cancer.

Gambogic Acid Induces HO-1 Expression and Cell Apoptosis through p38 Signaling in Oral Squamous Cell Carcinoma

Gambogic acid (GA), a natural and bioactive compound from the gamboge resin, has been reported to exhibit many oncostatic activities against several types of malignancies. However, its effects on the progression of oral squamous cell carcinoma (OSCC) remain largely unexplored. To fill this gap, we investigated the anticancer role of GA and molecular mechanisms underlying GA's actions in combating oral cancer. We found that GA negatively regulated the viability of OSCC cells, involving induction of the sub-G1 phase and cell apoptosis. In addition, a specific signature of apoptotic proteome, such as upregulation of heme oxygenase-1 (HO-1) and activation of caspase cascades, was identified in GA-treated OSCC. Moreover, such induction of HO-1 expression and caspase cleavage by GA was significantly diminished through the pharmacological inhibition of p38 kinase. In conclusion, these results demonstrate that GA promotes cell apoptosis in OSCC, accompanied with the activation of a p38-dependent apoptotic pathway. Our findings provide potential avenues for the use of GA with high safety and therapeutic implications in restraining oral cancer.

Deoxyshikonin Mediates Heme Oxygenase-1 Induction and Apoptotic Response via p38 Signaling in Tongue Cancer Cell Lines

Deoxyshikonin (DSK), a phytochemical constituent, has been documented to elicit various oncostatic properties alone or in combination with established therapeutics. However, its role in restraining oral squamous cell carcinoma (OSCC) is mostly unclear. Here, we examined the tumor-suppressive effect of DSK and explored the molecular mechanisms underlying DSK’s activities on controlling oral cancer. Our results showed that DSK dose-dependently lessened the cell viability of tongue cancer cell lines, involving induction of cell cycle arrest at the sub-G1 phase and apoptotic cell death. Moreover, a unique signature of apoptosis-related proteins, including augmented nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) expression and caspase activation, was observed in DSK-treated tongue cancer cell lines. Furthermore, DSK-mediated upregulation of HO-1 and cleavage of caspase-9 and -3 were significantly inhibited by pharmacological blockage of p38 kinase. Collectively, these data revealed that DSK halted cell cycle progression and elicited cell apoptosis in tongue cancer cell lines, reshaping a p38-dependent profile of apoptotic proteome. Our findings provided novel insights into the therapeutic implications of a natural compound on the management of OSCC.

Curcumin analog HO-3867 triggers apoptotic pathways through activating JNK1/2 signalling in human oral squamous cell carcinoma cells

Human oral squamous cell carcinoma (OSCC) is the common head and neck malignancy in the world. While surgery, radiotherapy and chemotherapy are emerging as the standard treatment for OSCC patients, the outcome is limited to the recurrence and side effects. Therefore, patients with OSCC require alternative strategies for treatment. In this study, we aimed to explore the therapeutic effect and the mode of action of the novel curcumin analog, HO-3867, against human OSCC cells. We analysed the cytotoxicity of HO-3867 using MTT assay. In vitro mechanic studies were performed to determine whether MAPK pathway is involved in HO-3867 induced cell apoptosis. As the results, we found HO-3867 suppressed OSCC cells growth effectively. The flow cytometry data indicate that HO-3867 induce the sub-G1 phase. Moreover, we found that HO-3867 induced cell apoptosis by triggering formation of activated caspase 3, caspase 8, caspase 9 and PARP. After dissecting MAPK pathway, we found HO-3867 induced cell apoptosis via the c-Jun N-terminal kinase (JNK)1/2 pathway. Our results suggest that HO-3867 is an effective anticancer agent as its induction of cell apoptosis through JNK1/2 pathway in human oral cancer cells.