Therapeutic effect of TMZ-POH on human nasopharyngeal carcinoma depends on reactive oxygen species accumulation

Molecular pharmacology and therapeutic advances of monoterpene perillyl alcohol

BACKGROUND

Perillyl alcohol (POH) is a aroma monoterpene commonly obtained from various plants' essential oil. Recently, increasing researches have demonstrated that POH may be useful, not only as flavor compound, but also as bioactive molecule because of a variety of biological activities.

PURPOSE

The aim of this review is to summarize the production, pharmacological activities and molecular mechanism, active derivatives, toxicity and parmacokinetics, and industrial application of POH.

METHODS

A systematic search of published articles up to January 2024 in Web of Science, China Knowledge Network, and PubMed databases is conducted using the following keywords: POH, POH derivatives, biological or pharmacological, production or synthesis, pharmacokinetics, toxicity and application.

RESULTS

Biotechnological production is considered to be a potential alternative approach to generate POH. POH provides diverse pharmacological benefits, including anticancer, antimicrobial, insecticidal, antioxidant, anti-inflammatory, hypotensive, vasorelaxant, antinociceptive, antiasthmatic, hepatoprotective effects, etc. The underlying mechanisms of action include modulation of NF-κB, JNK/c-Jun, Notch, Akt/mTOR, PI3K/Akt/eNOS, STAT3, Nrf2 and ERS response pathways, mitigation of mitochondrial dysfunction and membrane integrity damage, and inhibition of ROS accumulation, pro-inflammatory cytokines release and NLRP3 activation. What's more, the proteins or genes influenced by POH against diseases refer to Bax, Bcl-2, cyclin D1, CDK, p21, p53, HIF-1α, AP-1, caspase-3, M6P/IGF2R, PARP, VEGF, etc. Some clinical studies report that intranasal delivery of POH is a safe and effective treatment for cancer, but further clinical investigations are needed to confirm other health benefits of POH in human healthy. Depending on these health-promoting properties together with desirable flavor and safety, POH can be employed as dietary supplement, preservative and flavor additive in food and cosmetic fields, as building block in synthesis fields, as anticancer drug in medicinal fields, and as pesticides and herbicides in agricultural fields.

CONCLUSION

This review systematically summarizes the recent advances in POH and highlights its therapeutic effects and potential mechanisms as well as the clinical settings, which is helpful to develop POH into functional food and new candidate drug for prevention and management of diseases. Future studies are needed to conduct more biological activity studies of POH and its derivatives, and check their clinical efficacy and potential side effects.

Activation of Epstein-Barr Virus' Lytic Cycle in Nasopharyngeal Carcinoma Cells by NEO212, a Conjugate of Perillyl Alcohol and Temozolomide

The Epstein-Barr virus (EBV) is accepted as a primary risk factor for certain nasopharyngeal carcinoma (NPC) subtypes, where the virus persists in a latent stage which is thought to contribute to tumorigenesis. Current treatments are sub-optimal, and recurrence occurs in many cases. An alternative therapeutic concept is aimed at triggering the lytic cycle of EBV selectively in tumor cells as a means to add clinical benefit. While compounds able to stimulate the lytic cascade have been identified, their clinical application so far has been limited. We are developing a novel anticancer molecule, NEO212, that was generated by covalent conjugation of the alkylating agent temozolomide (TMZ) to the naturally occurring monoterpene perillyl alcohol (POH). In the current study, we investigated its potential to trigger the lytic cycle of EBV in NPC cells in vitro and in vivo. We used the established C666.1 cell line and primary patient cells derived from the brain metastasis of a patient with NPC, both of which harbored latent EBV. Upon treatment with NEO212, there was an increase in EBV proteins Zta and Ea-D, key markers of the lytic cycle, along with increased levels of CCAAT/enhancer-binding protein homologous protein (CHOP), a marker of endoplasmic reticulum (ER) stress, followed by the activation of caspases. These effects could also be confirmed in tumor tissue from mice implanted with C666.1 cells. Towards a mechanistic understanding of these events, we used siRNA-mediated knockdown of CHOP and inclusion of anti-oxidant compounds. Both approaches blocked lytic cycle induction by NEO212. Therefore, we established a sequence of events, where NEO212 caused reactive oxygen species (ROS) production, which triggered ER stress and elevated the levels of CHOP, which was required to stimulate the lytic cascade of EBV. Inclusion of the antiviral agent ganciclovir synergistically enhanced the cytotoxic impact of NEO212, pointing to a potential combination treatment for EBV-positive cancers which should be explored further. Overall, our study establishes NEO212 as a novel agent able to stimulate EBV's lytic cycle in NPC tumors, with implications for other virus-associated cancers.

Prognostic impact of pretreatment serum superoxide dismutase activity in patients with locoregionally advanced nasopharyngeal carcinoma

PURPOSE

To evaluate the prognostic effect of pretreatment serum superoxide dismutase (SOD) activity in locoregionally advanced nasopharyngeal carcinoma.

METHODS

A total of 498 patients diagnosed with stage III-IVA nasopharyngeal carcinoma between January 2013 and December 2016 were involved in this study. The X-tile program was used to determine the cut-off value of pretreatment serum SOD activity based on disease-free survival. Kaplan-Meier methods and Cox proportional hazards models were used to evaluate the impact of serum SOD levels on survival outcomes. The receiver operating characteristic (ROC) curve analysis was used to compare the prognostic value of clinical stage, pretreatment serum SOD level, and the combination of them regarding disease-free survival.

RESULTS

Based on the X-tile plot, the optimal cutoff value of pretreatment serum SOD activity for disease-free survival was 146.0U/mL. As a dichotomous variable, SOD was significantly higher in non-keratinizing differentiated disease (P = 0.027) and early T stage (P = 0.011). Compared with the lower subset, higher SOD activity predicted an inferior 3-year rates of overall survival (84.6 vs. 94.7%, P < 0.001), distant metastasis-free survival (78.3 vs. 92.8%, P < 0.001) and disease-free survival (78.2 vs. 92.8%, P < 0.001). Multivariate analysis verified that the SOD activity was an independent prognostic indicator to predict distant metastasis, disease progression, and death. The area under the ROC curve (AUC) of the combination was superior to that of clinical stage or SOD alone for disease-free survival (both P < 0.01).

CONCLUSION

Serological SOD activity before treatment is an important prognostic indicator for patients with stage III-IV non-metastatic nasopharyngeal carcinoma undergoing chemoradiation therapy.

β-elemene combined with temozolomide in treatment of brain glioma

Temozolomide (TMZ) is a widely used chemotherapeutic agent for malignant glioma. β-Elemene has been reported to have the ability of passing through the blood-brain barrier and reverse multidrug resistance. In the present study, transport of drugs through the in vitro blood-brain barrier (BBB) model also suggested that β-elemene can assist in TMZ transport to the brain. Plasma and brain pharmacokinetics demonstrated that when β-elemene is used in combination with TMZ, the metabolic rate of TMZ in plasma is slowed, and mean residence time (MRT) in brain is prolonged. The brain tissue distribution at 1 h indicated that the combination of TMZ and β-elemene promotes the distribution of β-elemene in the brain but slightly reduces the distribution of TMZ in the brain. Furthermore the antitumor effect and toxicity in vivo were also investigated. The combination of β-elemene and TMZ was well tolerated and significantly inhibited tumor growth in glioma xenografts. In summary, the present study indicates a synergistic antitumor effect of β-elemene and TMZ in glioma.

Pharmacokinetic properties of the temozolomide perillyl alcohol conjugate (NEO212) in mice

Background

NEO212 is a novel small-molecule anticancer agent that was generated by covalent conjugation of the natural monoterpene perillyl alcohol (POH) to the alkylating agent temozolomide (TMZ). It is undergoing preclinical development as a therapeutic for brain-localized malignancies. The aim of this study was to characterize metabolism and pharmacokinetic (PK) properties of NEO212 in preclinical models.

Methods

We used mass spectrometry (MS) and modified high-performance liquid chromatography to identify and quantitate NEO212 and its metabolites in cultured glioblastoma cells, in mouse plasma, brain, and excreta after oral gavage.

Results

Our methods allowed identification and quantitation of NEO212, POH, TMZ, as well as primary metabolites 5-aminoimidazole-4-carboxamide (AIC) and perillic acid (PA). Intracellular concentrations of TMZ were greater after treatment of U251TR cells with NEO212 than after treatment with TMZ. The half-life of NEO212 in mouse plasma was 94 min. In mice harboring syngeneic GL261 brain tumors, the amount of NEO212 was greater in the tumor-bearing hemisphere than in the contralateral normal hemisphere. The brain:plasma ratio of NEO212 was greater than that of TMZ. Excretion of unaltered NEO212 was through feces, whereas its AIC metabolite was excreted via urine.

Conclusions

NEO212 preferentially concentrates in brain tumor tissue over normal brain tissue, and compared to TMZ has a higher brain:plasma ratio, altogether revealing favorable features to encourage its further development as a brain-targeted therapeutic. Its breakdown into well-characterized, long-lived metabolites, in particular AIC and PA, will provide useful equivalents for PK studies during further drug development and clinical trials with NEO212.

Cytotoxic impact of a perillyl alcohol-temozolomide conjugate, NEO212, on cutaneous T-cell lymphoma in vitro

Background:

Mycosis fungoides (MF) and Sézary syndrome (SS) are subtypes of primary cutaneous lymphomas and represent complex diseases regarding their physiopathology and management. Depending on the stage of the disease, different treatment regimens are applied, but there is no consensus on an optimal approach. Prognosis for patients with early stage MF is favorable, but significantly worsens in advanced disease and in SS, where patients frequently relapse and require multiple therapies.

Methods:

We investigated the potential anticancer effects of NEO212, a novel compound generated by covalently conjugating perillyl alcohol (a natural monoterpene) to temozolomide (an alkylating agent), on MF and SS cell lines in vitro. HUT-78, HUT-102, and MyLa cells were treated with NEO212 under different conditions, and drug effects on proliferation, viability, and apoptosis were characterized.

Results:

NEO212 inhibited proliferation, diminished viability, and stimulated apoptosis in all cell lines, although with varying degrees of potency in the different cell lines. It down-regulated c-myc and cyclin D1 proteins, which are required for cell proliferation, but triggered endoplasmic reticulum stress and activation of caspases. Pretreatment of cells with antioxidants ascorbic acid and beta-mercaptoethanol prevented these NEO212-induced effects.

Conclusions:

NEO212 exerted promising anticancer effects on SS and MF cell lines. The generation of reactive oxygen species (ROS) appears to play a key role in the NEO212-induced cell death process, because the blockage of ROS with antioxidants prevented caspase activation. We propose that NEO212 should be investigated further toward clinical testing in these tumor types.

NEO212 induces mitochondrial apoptosis and impairs autophagy flux in ovarian cancer

Background

Temozolomide-perillyl alcohol conjugate (NEO212), a novel temozolomide (TMZ) analog, was previously reported to exert its anti-cancer effect in non-small cell lung cancer (NSCLC), and human nasopharyngeal carcinoma (NPC), etc.. In the current study, we intend to illuminate the potential anticancer property and the underly mechanisms of NEO212 in ovarian cancer cells.

Methods

The cytotoxicity of NEO212 was detected by MTT, colony formation analysis and xenograft model. The proteins involved in cell proliferation, DNA damage, autophagy and lysosomal function were detected by western blots; mitochondria, lysosome and autophagosome were visualized by TEM and/or immunofluorescence; Apoptosis, cell cycle analysis and mitochondrial transmembrane potential were detected by flow cytometry. TFEB translocation was detected by immunofluorescence and western blot.

Results

NEO212 has the potential anticancer property in ovarian cancer cells, as evidence from cell proliferation inhibition, G₂/M arrest, DNA damage, xenograft, mitochondrial dysfunction and apoptosis. Importantly, we observed that although it induced significant accumulation of autophagosomes, NEO212 quenched GFP-LC3 degradation, down-regulated a series of lysosome related gene expression and blocked the autophagic flux, which significantly facilitated it induced apoptosis and was largely because it inhibited the nuclear translocation of transcription factor EB (EB).

Conclusions

NEO212 inhibited TFEB translocation, and impaired the lysosomal function, implying NEO212 might avoid from autophagy mediated chemo-resistance, thus proposing NEO212 as a potential therapeutic candidate for ovarian cancer.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1249-1) contains supplementary material, which is available to authorized users.

Temozolomide-Perillyl alcohol conjugate impairs Mitophagy flux by inducing lysosomal dysfunction in non-small cell lung Cancer cells and sensitizes them to irradiation

BACKGROUND

Temozolomide-perillyl alcohol conjugate (TMZ-POH), a novel Temozolomide (TMZ) analog developed based on the conjugation of TMZ and perillyl alcohol (POH), displayed strong anticancer potency in multiple cancer types. In this study, we aimed to clarify the relationship between TMZ-POH and autophagy, and explore the underlying mechanisms involved in.

METHODS

The proteins involved in autophagy, mitochondrial fission, lysosomal function and membrane traffic were detected by western blots; Autophagosome, mitochondria and lysosome were visualized by transmission electron microscope (TEM) and immunostaining; Apoptosis analysis and fluorescence probe detection were applied by flow cytometry.

RESULTS

TMZ-POH blocked mitophagy flux although the number of autophagosomes which colocalized with mitochondria in the cells was increased via inducing lysosomal dysfunction as evidence from impaired lysosomal acidification, maturation and hampered autophagosome- lysosome fusion, which largely depended on its downregulation on the small GTPase RAB7A via mevalonate pathway. More importantly, our data demonstrated TMZ-POH sensitized cancer cell to irradiation induced apoptosis.

CONCLUSIONS

Temozolomide-perillyl alcohol conjugate impairs mitophagy flux by inducing lysosomal dysfunction in Non-Small Cell Lung Cancer (NSCLC) cells and sensitizes them to irradiation, thereby proposing TMZ-POH as a potential radiosensitizer.

Temozolomide-perillyl alcohol conjugate downregulates O6-methylguanin DNA methltransferase via inducing ubiquitination-dependent proteolysis in non-small cell lung cancer

The DNA repair enzyme O⁶-methylguanin-DNA-methltransferase (MGMT) is able to remove products of alkylating agent such as O⁶-meG and emerges as a central determinant of cancer resistance to temozolomide (TMZ). Temozolomide–perillyl alcohol conjugate (TMZ–POH), a novel TMZ analog developed based on the conjugation of TMZ and POH, displayed strong anticancer potency in multiple cancer types, but seemed not to experience the chemoresistance even in cells with high MGMT expression unlike TMZ and other alkylating agents. In this study, we demonstrated TMZ–POH inhibited MGMT dependent on proteasomal pathway and this inhibition is a significant factor in its toxic effect in the non-small cell lung cancer (NSCLC) cells.

Autophagy inhibitor facilitates gefitinib sensitivity in vitro and in vivo by activating mitochondrial apoptosis in triple negative breast cancer

Epidermal growth factor receptor (EGFR) is over-expressed in about 50% of Triple negative breast cancers (TNBCs), but EGFR inhibitors have not been effective in treating TNBC patients. Increasing evidence supports that autophagy was related to drug resistance at present. However, the role and the mechanism of autophagy to the treatment of TNBC remain unknown. In the current study, we investigated the effect of autophagy inhibitor to gefitinib (Ge) in TNBC cells in vitro and in nude mice vivo. Our study demonstrated that inhibition of autophagy by 3-Methyladenine or bafilomycin A1 improved Ge's sensitivity to MDA-MB-231 and MDA-MB-468 cells, as evidence from stronger inhibition of cell vitality and colony formation, higher level of G0/G1 arrest and DNA damage, and these effects were verified in nude mice vivo. Our data showed that the mitochondrial-dependent apoptosis pathway was activated in favor of promoting apoptosis in the therapy of Ge combined autophagy inhibitor, as the elevation of BAX/Bcl-2, Cytochrome C, and CASP3. These results demonstrated that targeting autophagy should be considered as an effective therapeutic strategy to enhance the sensitivity of EGFR inhibitors on TNBC.