Delta tocotrienol in recurrent ovarian cancer. A phase II trial

Circulating tumor DNA as a biomarker for predicting progression-free survival and overall survival in patients with epithelial ovarian cancer: a systematic review and meta-analysis

OBJECTIVES

Circulating tumor DNA (ctDNA) is emerging as a potential prognostic biomarker in multiple tumor types. However, despite the many studies available on small series of patients with ovarian cancer, a recent systematic review and meta-analysis is lacking. The objective of this study was to determine the association of ctDNA with progression-free-survival and overall survival in patients with epithelial ovarian cancer.

METHODS

An electronic search was conducted using PubMed (MEDLINE), Embase, CENTRAL (Cochrane Library), and CINAHL-Complete from January 2000 to September 15, 2023. To be included in the analysis the studies had to meet the following pre-specified inclusion criteria: (1) evaluable ctDNA; (2) progression-free-survival and overall survival reported as hazard ratio (HR); and (3) the patient population had epithelial ovarian cancer at the time of ctDNA detection. We evaluated the association of ctDNA with progression-free survival and overall survival. Secondary outcomes focused on sub-group analysis of genomic alterations and international Federation of Gynecology and Obstetrics (FIGO) stage.

RESULTS

A total of 26 studies reporting on 1696 patients with epithelial ovarian cancer were included. The overall concordance rate between plasma-based and tissue-based analyses was approximately 62%. We found that a high level of ctDNA in epithelial ovarian cancer was associated with worse progression-free survival (HR 5.31, 95% CI 2.14 to 13.17, p<0.001) and overall survival (HR 2.98, 95% CI 1.86 to 4.76, p<0.0001). The sub-group analysis showed a greater than threefold increase in the risk of relapse in patients with positive HOXA9 meth-ctDNA (HR 3.84, 95% CI 1.57 to 9.41, p=0.003).

CONCLUSIONS

ctDNA was significantly associated with worse progression-free survival and overall survival in patients with epithelial ovarian cancer. Further prospective studies are needed.

PROSPERO REGISTRATION NUMBER

CRD42023469390.

Different Roles of Tocopherols and Tocotrienols in Chemoprevention and Treatment of Prostate Cancer

The vitamin E family contains α-tocopherol (αT), βT, γT, and δT and α-tocotrienol (TE), βTE, γTE, and δTE. Research has revealed distinct roles of these vitamin E forms in prostate cancer (PCa). The ATBC trial showed that αT at a modest dose significantly decreased PCa mortality among heavy smokers. However, other randomized controlled trials including the Selenium and Vitamin E Cancer Prevention Trial (SELECT) indicate that supplementation of high-dose αT (≥400 IU) does not prevent PCa among nonsmokers. Preclinical cell and animal studies also do not support chemopreventive roles of high-dose αT and offer explanations for increased incidence of early-stage PCa reported in the SELECT. In contrast, accumulating animal studies have demonstrated that γT, δT, γTE, and δTE appear to be effective for preventing early-stage PCa from progression to adenocarcinoma in various PCa models. Existing evidence also support therapeutic roles of γTE and its related combinations against advanced PCa. Mechanistic and cell-based studies show that different forms of vitamin E display varied efficacy, that is, δTE ≥ γTE > δT ≥ γT >> αT, in inhibiting cancer hallmarks and enabling characteristics, including uncontrolled cell proliferation, angiogenesis, and inflammation possibly via blocking 5-lipoxygenase, nuclear factor κB, hypoxia-inducible factor-1α, modulating sphingolipids, and targeting PCa stem cells. Overall, existing evidence suggests that modest αT supplement may be beneficial to smokers and γT, δT, γTE, and δTE are promising agents for PCa prevention for modest-risk to relatively high-risk population. Despite encouraging preclinical evidence, clinical research testing γT, δT, γTE, and δTE for PCa prevention is sparse and should be considered.

Prognostic impact of early ctDNA dynamics during chemotherapy of metastatic cancer

Aim: Clinical utility of the dynamics of ctDNA is sparse. This study aimed at evaluating the prognostic impact of early ctDNA dynamics in patients with metastatic cancer treated with chemotherapy. Materials & methods: The ctDNA dynamics were evaluated in 595 patients with metastatic cancer using droplet digital PCR. Results: Patients with an increase in ctDNA after one treatment cycle (n = 73; 12.2%) had an overall survival of 5.6 months compared with 8.6 months in patients with stable or decreasing ctDNA (n = 328; 55.1%) and 21.0 months in patients with undetectable ctDNA (p < 0.001; hazard ratio: 0.47; 95% CI: 0.41-0.53). Conclusion: Early ctDNA dynamics hold important prognostic information and have great implications for evaluation with the perspective of a more individualized treatment strategy.

Delta tocotrienol as a supplement to FOLFOXIRI in first-line treatment of metastatic colorectal cancer. A randomized, double-blind, placebo-controlled phase II study

PURPOSE

Triplet chemotherapy might be more effective than doublet chemotherapy in metastatic colorectal cancer (mCRC), but it may also be marked by increased toxicity. To investigate whether δ-tocotrienol, a vitamin E analogue, with possible neuroprotective and anti-inflammatory effects, reduces the toxicity of triplet chemotherapy, we conducted a randomized, double-blind, placebo-controlled trial in mCRC patients receiving first-line 5-fluorouracil, oxaliplatin and irinotecan (FOLFOXIRI).

MATERIAL AND METHODS

Seventy patients with mCRC were randomly assigned (1:1) to receive FOLFOXIRI plus either δ-tocotrienol or placebo at the Department of Oncology, Vejle Hospital, Denmark. Eligibility criteria were adenocarcinoma in the colon or rectum, age 18-75 years and ECOG performance status 0-1. FOLFOXIRI was given in eight cycles followed by four cycles of 5-fluorouracil. δ-tocotrienol 300 mg or placebo × 3 daily was added during chemotherapy and for a maximum of two years. The primary endpoint was time to hospitalization or death during treatment with chemotherapy.

RESULTS

Median time to first hospitalization or death was 3.7 months in the placebo group (95% CI 1.93-not reached (NR)), and was NR in the δ-tocotrienol group (95% CI 1.87-NR) with a hazard ratio of 0.70 (95% CI 0.36-1.36). Grade 3-4 toxicities were uncommon in both groups, except for neutropenia, which occurred in 19 patients (58%) in the placebo group and 17 patients (50%) in the δ-tocotrienol group. There were no grade 3 or 4 peripheral sensory neuropathy. In the placebo group, 24 patients (71%) had oxaliplatin dose reductions compared to 17 patients (47%) in the δ-tocotrienol group (p = 0.047).

CONCLUSION

The addition of δ-tocotrienol to FOLFOXIRI did not statistically significant prolong the time to first hospitalization or death compared to FOLFOXIRI plus placebo. Toxicity was manageable and not statistically different. There was a statistically significant difference in dose reductions of oxaliplatin pointing to a possible neuroprotective effect of δ-tocotrienol.

Advances in application of circulating tumor DNA in ovarian cancer

Ovarian cancer is the third most common gynecologic cancer worldwide and has the highest mortality rate among gynecologic cancers. Identifying timely and effective biomarkers at different stages of the disease is the key to improve the prognosis of ovarian cancer patients. Circulating tumor DNA (ctDNA) is a fragment of free DNA produced by tumor cells in the blood. Current techniques for detecting ctDNA mainly include quantitative polymerase chain reaction (PCR), targeted next-generation sequencing (NGS), and non-targeted NGS (such as whole exon or whole genome sequencing). As a non-invasive liquid biopsy technique, ctDNA has a good application prospect in the ovarian cancer diagnosis, monitoring of treatment response and efficacy evaluation, detection of reverse mutation and related medication guidance, and prognosis evaluation. This article reviews the advances in application of ctDNA in ovarian cancer.

Phase II trial of delta-tocotrienol in neoadjuvant breast cancer with evaluation of treatment response using ctDNA

Neoadjuvant treatment of breast cancer is applied to an increasing extent, but treatment response varies and side effects pose a challenge. The vitamin E isoform delta-tocotrienol might enhance the efficacy of chemotherapy and reduce the risk of side effects. The aim of this study was to investigate the clinical effect of delta-tocotrienol combined with standard neoadjuvant treatment and the possible association between detectable circulating tumor DNA (ctDNA) during and after neoadjuvant treatment with pathological treatment response. This open-label, randomized phase II trial included 80 women with newly diagnosed, histologically verified breast cancer randomized to standard neoadjuvant treatment alone or in combination with delta-tocotrienol. There was no difference in the response rate or frequency of serious adverse events between the two arms. We developed a multiplex digital droplet polymerase chain reaction (ddPCR) assay for the detection of ctDNA in breast cancer patients that targets a combination of two methylations specific for breast tissue (LMX1B and ZNF296) and one cancer specific methylation (HOXA9). The sensitivity of the assay increased when the cancer specific marker was combined with the ones specific to breast tissue (p < 0.001). The results did not show any association between ctDNA status and pathological treatment response, neither at midterm nor before surgery.

Effect of vitamins C and E on cancer survival; a systematic review

PURPOSE

Association between vitamins C (VC)/ E (VE) and cancer survival is inconsistent. This systematic review is aimed to summarize trials for effects of VC/VE on cancer survival.

METHODS

Relevant English trials were retrieved from PubMed, Cochrane Library, Embase, Web of Science, Scopus databases, and Clinicaltrials.gov through 21/June/2022. Inclusion criteria were all trials which assessed sole/combinations intake of VC/VE on survival rate, mortality, or remission of any cancer. Exclusion criteria were observational and animal studies.

RESULTS

We reached 30 trials conducted on 38,936 patients with various cancers. Due to severe methodological heterogeneity, meta-analysis was impossible. High dose VC + chemotherapy or radiation was safe with an overall survival (OS) 182 days - 21.5 months. Sole oral or intravenous high dose VC was safe with non-significant change in OS (2.9-8.2 months). VE plus chemotherapy was safe, resulted in stabling diseases for 5 years in 70- 86.7% of patients and OS 109 months. It was found 60% and 16% non-significant reductions in adjusted hazard ratio (HR) deaths or recurrence by 200 mg/d tocotrienol + tamoxifen in breast cancer, respectively. Sole intake of 200-3200 mg/d tocotrienol before resectable pancreatic cancer was safe and significantly increased cancer cells' apoptosis. Combination VC and VE was non-significantly reduced 7% in rate of neoplastic gastric polyp.

CONCLUSION

Although our study is supported improvement of survival and progression rates of cancers by VC/VE, more high quality trials with large sample sizes are required to confirm.

PROSPERO REGISTRATION NUMBER

CRD42020152795.

Tocotrienol in the Treatment of Topical Wounds: Recent Updates

Healing wounds is an important attempt to keep the internal higher organs safe. Complications in topical wound healing may lead to the formation of scars, which can affect the patient's quality of life. Although several approaches are ongoing in parallel in the exploration of natural compounds via advanced delivery, in this article, an attempt has been made to highlight tocotrienol. Tocotrienol is a natural form of vitamin E and has shown its potential in certain pharmacological activities better than tocopherol. Its antioxidant, anti-inflammatory, cell signal-mediating effects, angiogenic properties, management of scar, and promotion of wound environment with essential factors have shown potential in the management of topical wound healing. Therefore, this review has aimed to focus on recent advances in topical wound healing through the application of tocotrienols. Challenges in delivering tocotrienols to the topical wound due to its large molecular weight and higher logP have also been explored using nanotechnological-based carriers, which has made tocotrienol a potential tool to facilitate the closure of wounds. Exploration of tocotrienol has also been made in human volunteers for biopsy wounds; however, the results are yet to be reported. Overall, based on the current findings in the literature, it could be inferred that tocotrienol would be a viable alternative to the existing wound dressing components for the management of topical wounds.

The Clinical Impact of Methylated Homeobox A9 ctDNA in Patients with Non-Resectable Biliary Tract Cancer Treated with Erlotinib and Bevacizumab

Methylated homeobox A9 (meth-HOXA9) is tumor specific and has been suggested as a prognostic biomarker in several types of cancer. ctDNA measured as meth-HOXA9 may be a valuable biomarker in the decision-making process about last-line treatment of biliary tract cancer (BTC). The aim of the study was to investigate the clinical impact of meth-HOXA9 in plasma from patients receiving erlotinib and bevacizumab for late-stage BTC and to investigate the treatment effect and adverse events. Droplet digital PCR was applied to detect meth-HOXA9 in 39 patients. Response rates were registered according to RECIST (1.1) and adverse events according to Common Terminology Criteria for Adverse Events Version 4.0 (CTCAE (4.0)). Endpoints were progression-free survival (PFS), overall survival (OS), response rate, and toxicity. A significant difference in PFS and OS between patients with increasing and non-increasing meth-HOXA9 was detected after one treatment cycle, hazard ratio (HR) 12.4 (p < 0.0001) and HR 2.75 (p = 0.04), respectively. The most common adverse events of erlotinib were fatigue, pain, and rash, and those of bevacizumab were bleeding and wounds. This study found meth-HOXA9 to be negatively associated with survival in patients with late-stage BTC. Hence, meth-HOXA9 may guide early discontinuation of ineffective treatment.

Revisiting the therapeutic potential of tocotrienol

The therapeutic potential of the tocotrienol group stems from its nutraceutical properties as a dietary supplement. It is largely considered to be safe when consumed at low doses for attenuating pathophysiology as shown by animal models, in vitro assays, and ongoing human trials. Medical researchers and the allied sciences have experimented with tocotrienols for many decades, but its therapeutic potential was limited to adjuvant or concurrent treatment regimens. Recent studies have focused on targeted drug delivery by enhancing the bioavailability through carriers, self-sustained emulsions, nanoparticles, and ethosomes. Epigenetic modulation and computer remodeling are other means that will help increase chemosensitivity. This review will focus on the systemic intracellular anti-cancer, antioxidant, and anti-inflammatory mechanisms that are stimulated and/or regulated by tocotrienols while highlighting its potent therapeutic properties in a diverse group of clinical diseases.

The Emerging Role of Cyclin-Dependent Kinase Inhibitors in Treating Diet-Induced Obesity: New Opportunities for Breast and Ovarian Cancers?

Overweight and obesity constitute the most impactful lifestyle-dependent risk factors for cancer and have been tightly linked to a higher number of tumor-related deaths nowadays. The excessive accumulation of energy can lead to an imbalance in the level of essential cellular biomolecules that may result in inflammation and cell-cycle dysregulation. Nutritional strategies and phytochemicals are gaining interest in the management of obesity-related cancers, with several ongoing and completed clinical studies that support their effectiveness. At the same time, cyclin-dependent kinases (CDKs) are becoming an important target in breast and ovarian cancer treatment, with various FDA-approved CDK4/6 inhibitors that have recently received more attention for their potential role in diet-induced obesity (DIO). Here we provide an overview of the most recent studies involving nutraceuticals and other dietary strategies affecting cell-cycle pathways, which might impact the management of breast and ovarian cancers, as well as the repurposing of already commercialized chemotherapeutic options to treat DIO.

Impacts of nutritive and bioactive compounds on cancer development and therapy

For persons who survive with progressive cancer, nutritional therapy and exercise may be significant factors to improve the health condition and life quality of cancer patients. Nutritional therapy and medications are essential to managing progressive cancer. Cancer survivors, as well as cancer patients, are mostly extremely encouraged to search for knowledge about the selection of diet, exercise, and dietary supplements to recover as well as maintain their treatment consequences, living quality, and survival of patients. A healthy diet plays an important role in cancer treatment. Different articles are studied to collect information and knowledge about the use of nutrients in cancer treatment as well as cancer prevention. The report deliberates nutrition and exercise strategies during the range of cancer care, emphasizing significant concerns during treatment of cancer and for patients of advanced cancer, but concentrating mostly on the requirements of the population of persons who are healthy or who have constant disease following their repossession from management. It also deliberates choice nutrition and exercise problems such as dietary supplements, food care, food selections, and weight; problems interrelated to designated cancer sites, and common questions about diet, and cancer survival. Decrease the side effects of medicines both during and after treatment.

Prognostic Impact of Circulating Methylated Homeobox A9 DNA in Patients Undergoing Treatment for Recurrent Ovarian Cancer

Methylated Homeobox A9 circulating tumor DNA (meth-HOXA9) has been suggested as a blood-based biomarker in epithelial ovarian cancer (EOC), although its prognostic significance remains unproven. The aim of the present study was to investigate the prognostic impact of meth-HOXA9 in patients with recurrent EOC. DNA was purified from 4 mL plasma and, following bilsulfite conversion, meth-HOXA9 was analyzed using a methylation-specific droplet digital PCR. Detection of meth-HOXA9 was reported as a percentage of total DNA and as a binary variable (detectable and undetectable). Meth-HOXA9 status and its dynamics during palliative treatment were correlated with overall survival (OS) as the primary endpoint. At baseline, meth-HOXA9 was detected in 65.9% (83/126) of the patients. The median OS was 8.9 and 17.9 months in patients with detectable and undetectable meth-HOXA9 at baseline (hazard ratio: 2.04, p = 0.002), which remained significant in the multivariate analysis. Median OS in patients with an increase in meth-HOXA9 after one treatment cycle was 5.3 months compared to 33 months in patients with undetectable meth-HOXA9 (p < 0.001). Meth-HOXA9 was significantly related to poor survival and may serve as a prognostic marker in patients with recurrent EOC. The longitudinal monitoring of meth-HOXA9 is clinically feasible with the perspective of aiding clinical decision making.

Are Vitamin E Supplementation Beneficial for Female Gynaecology Health and Diseases?

Vitamin E is known as an essential vitamin, and many studies had demonstrated the importance of vitamin E throughout the reproductive process, such as miscarriage, premature birth, preeclampsia, and intrauterine growth restriction, which could be caused by a lack of vitamin E during pregnancy. Its potent antioxidant properties can counteract the oxidative stress induced by oxygen free radicals and imbalance of oxidative-antioxidant levels, hence it may play a role in maintaining the normal function of the female reproductive system. Despite the fact that vitamin E is acknowledged as the substance needed for reproduction, its beneficial effects on female fertility, gynaecological health, and diseases are still poorly understood and lacking. Therefore, the goal of this paper is to provide a summary of the known roles of vitamin E supplementation in women for gynaecological health and reproductive-related diseases, as well as its future perspective.

δ-Tocotrienol is the most potent vitamin E form in inhibiting prostate cancer cell growth and inhibits prostate carcinogenesis in Ptenp-/- mice

Vitamin E compounds, consisting of α, β, γ, and δ forms of tocopherols and tocotrienols, display different cancer preventive activities in experimental models. Tocotrienols may have higher potential for clinical use due to their lower effective doses in laboratory studies. However, most studies on tocotrienols have been carried out using cancer cell lines. Strong data from animal studies may encourage the use of tocotrienols for human cancer prevention research. To examine the cancer inhibitory activity of different vitamin E forms, we first investigated their inhibitory activities of different vitamin E forms in prostate cancer cell lines. We found that δ-tocotrienol (δT3) was the most effective form in inhibiting cell growth at equivalent doses. Because of this in vitro potency, δT3 was further studied using prostate specific Pten-/- (Ptenp-/-) mice. We found that 0.05% δT3 in diet reduced prostate adenocarcinoma multiplicity by 32.7%, featuring increased apoptosis and reduced cell proliferation. The inhibitory effect of 0.05% δT3 in diet was similar to that of 0.2% δ-tocopherol (δT) in diet reported previously. Our further study on the δT3-induced transcriptome changes indicated that δT3 inhibited genes in blood vessel development in the prostate of Ptenp-/- mice, which was confirmed by immunohistochemistry. Together, our results demonstrate that δT3 effectively inhibits the development of prostate adenocarcinoma in Ptenp-/- mice, which involves inhibition of proliferation and angiogenesis and promotion of apoptosis.

Scrubbed Palm Fatty Acid Distillate as Vitamin E Concentrate

Vitamin E (VitE) production from crude palm oil (CPO) has been extensively studied and industrially conducted. VitE in CPO is in the range of 600 to 1,000 ppm, and is usually produced from one of the main by-products of edible palm oil production, namely palm fatty acid distillate (PFAD). PFAD contains 4,000 to 5,500 ppm of VitE, and is produced from deodorization process of palm oil purification. This paper presents an innovative process of VitE concentrate production from CPO. A scrubber was designed and installed between the deodorizer and conventional PFAD scrubber. The main objective of this new scrubber was a recovery of glycerides from PFAD. This new scrubber is operated at 150 to 160℃. The scrubbed oil is named as Scrubbed Palm Fatty Acid Distillate (S-PFAD). This simple and efficient modified process can retrieve glycerides as S-PFAD at 0.3% recovery and it enhances VitE concentration in S-PFAD to the range of 28,000 to 32,000 ppm, which is the highest concentration of VitE that has ever been produced in the palm oil production. Fatty acids and glycerides in S-PFAD were esterified and transesterified to methyl esters. The methyl esters were evaporated from S-PFAD, and S-PFAD residue oil contained 24.7% VitE.

The Prognostic Value of Circulating Tumor DNA in Ovarian Cancer: A Meta-Analysis

Background: Studies have shown that circulating tumor DNA (ctDNA) indicates a poor prognosis in ovarian cancer. In this study, meta-analysis was used to assess the relationship between ctDNA and the prognosis of patients with epithelial ovarian cancer. Methods: The clinical trials included in this study were obtained via a search of PubMed, the Cochrane Library, the Web of Science and Embase between the period of establishment and March 2020. We selected clinical studies using qualitative or quantitative ctDNA methods to analyse the prognosis of ovarian epithelial cancer, screened the studies according to the determined inclusion and exclusion criteria, and used the modified JADAD score scale and NOS scale for evaluation, with OS (overall survival) and PFS (progression-free survival) as end events. The Cochrane Evaluation Tool was used to evaluate the quality of the randomized controlled trials. Stata 15.0 software was used to combine the effect ratio (hazard ratio, HR) and its 95% confidence interval (CI). In addition, a source analysis of ctDNA specimens, an analysis of ctDNA detection methods and a subgroup and sensitivity analysis of FIGO staging were performed. Results: A total of 8 studies were included in this meta-analysis, and ctDNA was found to be an independent risk factor for patients with epithelial ovarian cancer (OS: HR = 2.36, 95% CI [1.76,3.17], P < .001; PFS: HR = 2.51, 95% CI [1.83,3.45]). Conclusions: The results of our analysis suggested that ctDNA is a potential biomarker that can be used to evaluate the prognosis of patients with ovarian cancer.

The multifaceted roles of mitochondria at the crossroads of cell life and death in cancer

Mitochondria are the cytoplasmic organelles mostly known as the "electric engine" of the cells; however, they also play pivotal roles in different biological processes, such as cell growth/apoptosis, Ca²⁺ and redox homeostasis, and cell stemness. In cancer cells, mitochondria undergo peculiar functional and structural dynamics involved in the survival/death fate of the cell. Cancer cells use glycolysis to support macromolecular biosynthesis and energy production ("Warburg effect"); however, mitochondrial OXPHOS has been shown to be still active during carcinogenesis and even exacerbated in drug-resistant and stem cancer cells. This metabolic rewiring is associated with mutations in genes encoding mitochondrial metabolic enzymes ("oncometabolites"), alterations of ROS production and redox biology, and a fine-tuned balance between anti-/proapoptotic proteins. In cancer cells, mitochondria also experience dynamic alterations from the structural point of view undergoing coordinated cycles of biogenesis, fusion/fission and mitophagy, and physically communicating with the endoplasmic reticulum (ER), through the Ca²⁺ flux, at the MAM (mitochondria-associated membranes) levels. This review addresses the peculiar mitochondrial metabolic and structural dynamics occurring in cancer cells and their role in coordinating the balance between cell survival and death. The role of mitochondrial dynamics as effective biomarkers of tumor progression and promising targets for anticancer strategies is also discussed.

δ-Tocotrienol sensitizes and re-sensitizes ovarian cancer cells to cisplatin via induction of G1 phase cell cycle arrest and ROS/MAPK-mediated apoptosis

OBJECTIVES

Among gynaecologic malignancies, ovarian cancer (OC) represents the leading cause of death for women worldwide. Current OC treatment involves cytoreductive surgery followed by platinum-based chemotherapy, which is associated with severe side effects and development of drug resistance. Therefore, new therapeutic strategies are urgently needed. Herein, we evaluated the anti-tumour effects of Vitamin E-derived δ-tocotrienol (δ-TT) in two human OC cell lines, IGROV-1 and SKOV-3 cells.

MATERIALS AND METHODS

MTT and Trypan blue exclusion assays were used to assess δ-TT cytotoxicity, alone or in combination with other molecules. δ-TT effects on cell cycle, apoptosis, ROS generation and MAPK phosphorylation were investigated by flow cytometry, Western blot and immunofluorescence analyses. The synergism between δ-TT and chemotherapy was evaluated by isobologram analysis.

RESULTS

We demonstrated that δ-TT could induce cell cycle block at G1-S phase and mitochondrial apoptosis in OC cell lines. In particular, we found that the proapoptotic activity of δ-TT correlated with mitochondrial ROS production and subsequent JNK and p38 activation. Finally, we observed that the compound was able to synergize with cisplatin, not only enhancing its cytotoxicity in IGROV-1 and SKOV-3 cells but also re-sensitizing IGROV-1/Pt1 cell line to its anti-tumour effects.

CONCLUSIONS

δ-TT triggers G1 phase cell cycle arrest and ROS/MAPK-mediated apoptosis in OC cells and sensitizes them to platinum treatment, thus representing an interesting option for novel chemopreventive/therapeutic strategies for OC.

HOXA9-methylated DNA as a diagnostic biomarker of ovarian malignancy

Aim: In ovarian cancer, methylated HOXA9 (meth-HOXA9) has been proposed as a relevant biomarker, however, its role in the carcinogenic development remains unknown. This study aimed at evaluating meth-HOXA9 as a diagnostic biomarker in ovarian cancer. Materials & methods: The meth-HOXA9 status was examined in 138 tissue specimens encompassing normal ovaries, benign- and borderline tumors, and ovarian cancer using droplet digital PCR. Results: Meth-HOXA9 was detected in 93% (82/88) and 88% (14/16) of ovarian cancer and borderline tumors, respectively. In patients with benign ovarian tumors meth-HOXA9 was detected in 17% (3/18). Using receiver operating characteristic (ROC) analysis meth-HOXA9 had a diagnostic accuracy of 98%. Conclusion: Meth-HOXA9 is highly cancer specific and could serve as a general diagnostic marker of ovarian malignancy.

Analysis of HOXA9 methylated ctDNA in ovarian cancer using sense-antisense measurement

DNA promoter methylation is an early event in tumorigenesis and holds promise as a valuable marker in ovarian cancer (OC). It can be measured using circulating tumor specific DNA (ctDNA) isolated from the bloodstream. Sensitivity, however, is a limiting factor of its diagnostic feasibility in OC. DNA methylation analyses are based on bisulfite conversion, resulting in two DNA strands that are no longer complementary. The current standard strategy would then target only one of the double stranded DNA strands, but the potential to increase the sensitivity by targeting both DNA strands is available. In this study, we aimed at evaluating the diagnostic potential of methylated HOXA9 ctDNA in OC by targeting both the DNA sense and antisense strand. Methylated HOXA9 was detected in the plasma of 47/79 (59.5%) patients with newly diagnosed OC using sense-antisense droplet digital PCR. Simultaneous sense-antisense measurement increased the sensitivity by 14.6% (51.9% to 59.5%) as compared to antisense only. In patients with FIGO stage I-II disease the sensitivity was increased by 25%. In conclusion, simultaneous measurement targeting both DNA strands can increase the sensitivity and the analytical approach appears valuable in the diagnostic setting of OC.

Validating Methylated HOXA9 in Bronchial Lavage as a Diagnostic Tool in Patients Suspected of Lung Cancer

Diagnosing lung cancer requires invasive procedures with high risk of complications. Methylated tumor DNA in bronchial lavage has previously shown potential as a diagnostic biomarker. We aimed to develop and validate methylated HOXA9 in bronchial lavage as a diagnostic biomarker of lung cancer. Participants were referred on suspicion of lung cancer. Ten mL lavage fluid was collected at bronchoscopy for analysis of methylated HOXA9 based on droplet digital PCR according to our previously published method. HOXA9 status was compared with the final diagnosis. The Discovery and Validation cohorts consisted of 101 and 95 consecutively enrolled participants, respectively. In the discovery cohort, the sensitivity and specificity were 73.1% (95% CI 60.9-83.2%) and 85.3% (95% CI 68.9-95.0%), respectively. In the validation cohort, the values were 80.0% (95% CI 66.3-90.0%) and 75.6% (95% CI 60.5-87.1%), respectively. A multiple logistic regression model including age, smoking status, and methylated HOXA9 status resulted in an AUC of 84.9% (95% CI 77.3-92.4%) and 85.9% (95% CI 78.4-93.4%) for the Discovery and Validation cohorts, respectively. Methylated HOXA9 in bronchial lavage holds potential as a supplementary tool in the diagnosis of lung cancer with a clinically relevant sensitivity and specificity. It remained significant when adjusting for age and smoking status.

Role of Vitamin E in Selected Malignant Neoplasms in Women

Vitamin E, which is actually a mixture of eight isoforms (four tocopherols and four tocotrienols), is a powerful antioxidant that protects polyunsaturated fatty acids against oxidation and has the ability to break the chain lipid peroxidation, which is used in the treatment of heart disease, atherosclerosis, muscle disorders or infertility among men. Studies in-vitro show that one of the effects of tocopherol is the reduction of cancer stem cell activity which is connected to poor clinical course. In the scientific literature, reports on the participation of vitamin E not only in protection against the mutagenic effects of reactive oxygen species, but also in its anti-angiogenic activity and the ability to inhibit the invasion and metastasis of neoplastic cells are increasingly common. In this context, the role of vitamin E in preventing the neoplastic process and selected malignant neoplasms among women seems to be of particular interest. In this article, we present the results of research on the potential anticancer effects of vitamin E in the fight against breast, cervical, endometrial and ovarian cancer.

Phytocompounds Targeting Metabolic Reprogramming in Cancer: An Assessment of Role, Mechanisms, Pathways, and Therapeutic Relevance

The metabolism of cancer is remarkably different from that of normal cells and confers a variety of benefits, including the promotion of other cancer hallmarks. As the rewired metabolism is a near-universal property of cancer cells, efforts are underway to exploit metabolic vulnerabilities for therapeutic benefits. In the continued search for safer and effective ways of cancer treatment, structurally diverse plant-based compounds have gained substantial attention. Here, we present an extensive assessment of the role of phytocompounds in modulating cancer metabolism and attempt to make a case for the use of plant-based compounds in targeting metabolic vulnerabilities of cancer. We discuss the pharmacological interactions of phytocompounds with major metabolic pathways and evaluate the role of phytocompounds in the regulation of growth signaling and transcriptional programs involved in the metabolic transformation of cancer. Lastly, we examine the potential of these compounds in the clinical management of cancer along with limitations and challenges.

Tocotrienols: Dietary Supplements for Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is one of the leading causes of death worldwide. Emphysema and chronic bronchitis are the two major phenotypes of COPD, which have many symptoms, such as dyspnea, chronic cough, and mucus overproduction. Emphysema is characterized by the destruction of the alveolar wall, while chronic bronchitis is characterized by limitations in expiratory airflow. Cigarette smoking is the most significant risk factor for the pathogenesis of COPD in the developed world. Chronic inflammation contributes to the onset and progression of the disease and furthers the risk of comorbidities. Current treatment options and prevention strategies for COPD are very limited. Tocotrienols are a group of vitamin E molecules with antioxidant and anti-inflammatory properties. Individual tocotrienols (α, γ, and δ) have shown their ability to attenuate inflammation specifically via suppressing nuclear factor-κB-mediated cytokine production. The δ- and γ-forms of tocotrienols have been indicated as the most effective in the prevention of macrophage infiltration, production of reactive oxygen species, and cytokine secretion. This review briefly discusses the pathogenesis of COPD and the role of inflammation therein. Furthermore, we summarize the in vitro and in vivo evidence for the anti-inflammatory activity of tocotrienols and their potential application to COPD management. Coupled with the bioavailability and safety profile of tocotrienols, the ability of these compounds to modulate COPD progression by targeting the inflammation pathways renders them potential candidates for novel therapeutic approaches in the treatment of COPD patients.

δ-Tocotrienol induces apoptosis and inhibits proliferation of nasopharyngeal carcinoma cells

Nasopharyngeal carcinoma has a notably high incidence rate in Southern China, Southeast Asia, North Africa, Middle East, and the Arctic. δ-Tocotrienol is abundant in cereal and has some health benefits. In our recent study, we showed that δ-tocotrienol exerted anti-inflammatory effects in murine macrophages in vitro. The aim of this study was to further investigate the chemopreventive effects of δ-tocotrienol on human CNE1 cells. We showed that δ-tocotrienol induced apoptosis and cell cycle arrest at G₀/G₁ and M phases in nasopharyngeal carcinoma cells. Microarray analysis revealed that after CNE1 cells were treated with δ-tocotrienol, 169 genes were up-regulated and 167 down-regulated. ERK1/2 was shown to play a vital role in cell cycle arrest by gene chips. The results suggest that δ-tocotrienol induces cell cycle arrest in CNE1 cells via the p16/CDK4/cyclin D1 signaling pathway. Western blots showed that CNE1 apoptosis was related to dysregulated expression of Bax-2 and Bcl-2. Furthermore, caspase-3, -8, -9 up-regulation was related to the apoptotic effect of δ-tocotrienol; therefore, δ-tocotrienol triggers apoptosis in CNE1 cells through caspase-3 signaling. δ-Tocotrienol may potentially be developed as an anti-cancer agent in the management of nasopharyngeal carcinoma.

Epithelial ovarian cancer and the use of circulating tumor DNA: A systematic review

OBJECTIVE

One way to improve the survival rate of epithelial Ovarian Cancer (EOC) is by identifying effective biomarkers useful at different stages and time points of the disease. A potential biomarker is circulating tumor DNA (ctDNA) in plasma or serum. In this systematic review, we provide an overview of applications of ctDNA in EOC to discuss the direction of future research in this field.

METHODS

We performed a systematic search in Pubmed, Embase, and Scopus to identify relevant clinical studies eligible for inclusion. Furthermore, the references in the identified studies and relevant reviews were assessed to identify additional studies. The PRISMA guideline was employed to perform the systematic review, and data from the studies were extracted using piloted data extraction forms.

RESULTS

A total of 36 observational studies were included. The concordance between tumor and ctDNA was assessed in 19 studies, early diagnosis in 1, diagnosis in 23, monitoring of treatment response in 7, detection of reversion mutations in 3, prognosis in 9, but no studies assessed early detection of recurrence. Data from the studies were reported descriptively. The studies had a large variation in the methods used for ctDNA analysis and limited sample sizes of 10-126 patients. Overall, the studies show that ctDNA is a potential biomarker for EOC useful in several settings during assessment and treatment of these patients.

CONCLUSIONS

Although the identified studies are limited in number and their methods for ctDNA analysis vary, it is clear that ctDNA as a biomarker for EOC is promising for several applications in diagnostics, monitoring of treatment response, and prognostics. However, more studies are needed to establish the ideal methods and settings for the clinical use of ctDNA in EOC.

Angiogenesis Inhibitors for Colorectal Cancer. A Review of the Clinical Data

Since the late 1990s, therapy for metastatic colorectal cancer (mCRC) has changed considerably, and the combination of doublet or triplet chemotherapy and a targeted agent are now routinely used. The targeting of angiogenesis, the development of new blood vessels, represents a key element in the overall treatment strategy. Since the approval in 2004 of the first anti-angiogenetic drug, multiple agents have been approved and others are currently under investigation. We present an overview of the recent literature on approved systemic treatment of mCRC, with a focus on anti-angiogenic drugs, and current treatment approaches, and elaborate on the future role of angiogenesis in colorectal cancer as seen from a clinical perspective. The treatment of mCRC, in general, has changed from "one strategy fits all" to a more personalized approach. This is, however, not entirely the case for anti-angiogenetic treatments, partly due to a lack of validated biomarkers. The anti-angiogenetic standard treatment at the present primarily includes monoclonal antibodies. The therapeutic field of angiogenesis, however, has received increased interest after the introduction of newer combinations. These approaches will likely change the current treatment strategy, once again, to the overall benefit of patients.

The prognostic impact of circulating homeobox A9 methylated DNA in advanced non-small cell lung cancer

BACKGROUND

The homeobox A9 gene encodes a transcription factor, and aberrantly methylated homeobox A9 in the circulation has been suggested as a prognostic marker in early stage non-small cell lung cancer (NSCLC). The aim of the present study was to investigate the prognostic impact of methylated homeobox A9 in plasma from patients with advanced NSCLC.

METHODS

Blood samples were prospectively collected from patients with NSCLC stage III and IV receiving standard first line chemotherapy. Sampling took place before treatment initiation and subsequently before each treatment cycle. Plasma was stored at -80 °C until analysis. DNA was extracted, and following bisulfite conversion methylated homeobox A9 was analyzed by methylation specific droplet digital polymerase chain reaction. Detection of methylated homeobox A9 was assessed as a binary variable. The primary endpoint was overall survival (OS).

RESULTS

A total of 231 patients were included. At baseline methylated homeobox A9 was detected in 78.5% of the patients with a clear correlation to survival. The median OS for patients with and without detectable methylated homeobox A9 was 7.4 and 11.1 months, respectively [hazard ratio (HR) 1.79, 95% confidence interval (CI): 1.35-2.38, P<0.001]. The difference increased after the first cycle of treatment. At this time point the median OS was 6.2 and 15.6 months for patients with and without detectable methylated homeobox A9, respectively (HR 2.07, 95% CI: 1.58-2.73, P<0.001). The independent prognostic impact of detectable methylated homeobox A9 after one treatment cycle assessed by multiple Cox regression including known prognostic factors resulted in a HR of 3.79 (2.19-6.54, P<0.001) compared to undetectable methylated homeobox A9.

CONCLUSIONS

Measurable methylated homeobox A9 after the first treatment cycle may serve as a valuable prognostic marker in patients with advanced NSCLC. Routine clinical application with treatment reconsideration calls for further studies, preferably in prospective clinical trials.

Oncogenic and tumor suppressor function of MEIS and associated factors

MEIS proteins are historically associated with tumorigenesis, metastasis, and invasion in cancer. MEIS and associated PBX-HOX proteins may act as tumor suppressors or oncogenes in different cellular settings. Their expressions tend to be misregulated in various cancers. Bioinformatic analyses have suggested their upregulation in leukemia/lymphoma, thymoma, pancreas, glioma, and glioblastoma, and downregulation in cervical, uterine, rectum, and colon cancers. However, every cancer type includes, at least, a subtype with high MEIS expression. In addition, studies have highlighted that MEIS proteins and associated factors may function as diagnostic or therapeutic biomarkers for various diseases. Herein, MEIS proteins and associated factors in tumorigenesis are discussed with recent discoveries in addition to how they could be modulated by noncoding RNAs or newly developed small-molecule MEIS inhibitors.

Comparison of Mutated KRAS and Methylated HOXA9 Tumor-Specific DNA in Advanced Lung Adenocarcinoma

Circulating tumor DNA (ctDNA) has been suggested as a biomarker in non-small cell lung cancer. The optimal target for measuring ctDNA has not yet been established. This study aimed to investigate methylated Homeobox A9 (meth-HOXA9) as an approach to detect ctDNA in advanced lung adenocarcinoma and compare it with mutated Kirsten rat sarcoma viral oncogene homolog (mut-KRAS) in order to determine the mutual agreement. DNA was purified from formalin-fixed, paraffin-embedded non-malignant lung tissue and lung adenocarcinoma tissue, and plasma from healthy donors and lung adenocarcinoma patients, respectively. KRAS mutations in tumor tissue were identified by next-generation sequencing and quantified in tumor and plasma by droplet digital polymerase chain reaction (ddPCR). The meth-HOXA9 analysis was based on bisulfite-converted DNA from tumor and plasma and quantified by ddPCR. Samples consisted of 20 archival non-malignant lung tissues, 48 advanced lung adenocarcinomas with matched plasma samples, and 100 plasma samples from healthy donors. A KRAS mutation was found in the tumor in 34/48 (70.8%) adenocarcinoma patients. All tumors were positive for meth-HOXA9, while none of the non-malignant lung tissues were. Meth-HOXA9 was detected in 36/48 (75%) of plasma samples, and the median level was 0.7% (range of 0-46.6%, n = 48). Mut-KRAS was detected in 29/34 (85.3%) of the plasma samples, and the median level was 1.2% (range of 0-46.1%, n = 34). There was a good correlation between meth-HOXA9 and mut-KRAS in plasma (Spearman's rho 0.83, p < 0.001). Meth-HOXA9 is present in tissue from incurable lung adenocarcinoma but not in non-malignant lung tissue. It may be used as an approach for detecting ctDNA. The results demonstrated a high agreement between meth-HOXA9 and mut-KRAS in patients with advanced lung adenocarcinoma.

Carboplatin re-treatment in platinum-resistant epithelial ovarian cancer patients

PURPOSE

Treatment of multi-resistant epithelial ovarian cancer represents a clinical challenge with limited choices. Anti-angiogenic therapy has shown great potential in combination with frontline-therapy. Studies investigating heavily pre-treated patients are few. This study investigated the effect of re-treating patients with carboplatin combined with bevacizumab and cell-free DNA (cfDNA) as a potential predictor of outcome.

METHODS

This single-center study enrolled 73 multi-resistant ovarian cancer patients from 2008 to 2015. Patients were treated with a combination of bevacizumab (10 mg/kg) and carboplatin (AUC5) every 3 weeks. Baseline plasma samples were analyzed for cfDNA levels. Treatment response was evaluated based on the Response Evaluation Criteria in Solid Tumors (RECIST) criteria and CA125 blood values.

RESULTS

The response rate according to RECIST and/or CA125 was 57%. Median number of cycles was 6. The median progression-free survival and overall survival was 5.0 and 11.2 months, respectively. Eighteen patients developed allergic reactions to carboplatin. Patients were grouped into two cfDNA-groups according to median value. The cfDNA value was correlated to progression-free survival (PFS, p = 0.015), but not to overall survival (OS, p = 0.067) in the univariate analysis. In the multivariate analysis both PFS and OS were highly correlated to the levels of cfDNA (PFS, hazard ratio = 1.87, p = 0.012; OS, hazard ratio = 1.67, p = 0.037) with patients with high levels of cfDNA having poorest outcome.

CONCLUSION

Our results might provide guidance in cases with heavily pre-treated patients, where alternatives are limited. Carboplatin and bevacizumab treatment should be weighed against best supportive care, current non-platinum therapies and experimental treatment. cfDNA seems to offer prognostic insight.

De Novo High-Titer Production of Delta-Tocotrienol in Recombinant Saccharomyces cerevisiae

Delta-tocotrienol as a vitamin E isomer has received much attention because of its diverse biomedical applications. Microbial biosynthesis of delta-tocotrienol is a promising strategy for its economic and environmental advantages. Here, we accomplished complete biosynthesis of delta-tocotrienol in Saccharomyces cerevisiae from glucose. We first constructed and incorporated a heterologous pathway into the genome of S. cerevisiae by incorporating the genes hpd (from Pseudomonas putida KT2440), hpt (from Synechocystis sp. PCC 6803), and vte1 (from Arabidopsis thaliana) for the biosynthesis of delta-tocotrienol. We further enhanced the biosynthesis of the precursor geranylgeranyl diphosphate by overexpressing the thmg1 and ggppssa (from Sulfolobus acidocaldarius) genes, leading to a production titer of delta-tocotrienol of 1.39 ± 0.01 mg/L. Finally, we optimized the fermentation medium using the response surface methodology, enabling a high-titer production of delta-tocotrienol (3.56 ± 0.25 mg/L), ∼2.6-fold of that of the initial culture medium. Fed-batch fermentation in a 2 L fermenter was further used to enhance the production titer of delta-tocotrienol (4.10 ± 0.10 mg/L). To the best of our knowledge, this is the first report on the de novo biosynthesis of delta-tocotrienol in S. cerevisiae, and the highest titer obtained for microbial production of delta-tocotrienol.

miR-429 inhibits osteosarcoma progression by targeting HOXA9 through suppressing Wnt/β-catenin signaling pathway

Osteosarcoma (OS) is the most commonly diagnosed malignant cancer of bone that occurs in adolescents and children. Mounting number of studies have indicated that miRNAs are increasingly playing fundamental roles in OS development. Thus, the biological function of miR-429 in OS progression was explored. The results of RT-qPCR revealed that miR-429 was downregulated in OS tissues and OS cell lines (MG-63, U2OS, Saos-2) while homeobox A9 (HOXA9) was markedly increased. Moreover, HOXA9 was confirmed as a direct target of miR-429 by using luciferase reporter assay. It was identified that miR-429 exhibited a suppressive effect on OS progression while HOXA9 showed the oncogenic function in OS progression by using MTT and Transwell assays. More importantly, rescue assays manifested that HOXA9 can partially overturn the suppressive effect of miR-429 on OS. Overexpression of miR-429 inhibited the activation of Wnt/β-catenin signaling pathway. In conclusion, miR-429 suppressed OS progression by targeting HOXA9 through Wnt/β-catenin pathway.

Vitamin E and cancer prevention: Studies with different forms of tocopherols and tocotrienols

α-Tocopherol (α-T) is the major form of vitamin E (VE) in animals and has the highest activity in carrying out the essential antioxidant functions of VE. Because of the involvement of oxidative stress in carcinogenesis, the cancer prevention activity of α-T has been studied extensively. Lower VE intake or nutritional status has been shown to be associated with increased cancer risk, and supplementation of α-T to populations with VE insufficiency has shown beneficial effects in lowering the cancer risk in some intervention studies. However, several large intervention studies with α-T conducted in North America have not demonstrated a cancer prevention effect. More recent studies have centered on the γ- and δ-forms of tocopherols and tocotrienols (T3). In comparison with α-T, these forms have much lower systemic bioavailability but have shown stronger cancer-preventive activities in many studies in animal models and cell lines. γ-T3 and δ-T3 generally have even higher activities than γ-T and δ-T. In this article, we review recent results from human and laboratory studies on the cancer-preventive activities of different forms of tocopherols and tocotrienols, at nutritional and pharmacological levels. We aim to elucidate the possible mechanisms of the preventive actions and discuss the possible application of the available information for human cancer prevention by different VE forms.

Potential Role of Tocotrienols on Non-Communicable Diseases: A Review of Current Evidence

Tocotrienol (T3) is a subfamily of vitamin E known for its wide array of medicinal properties. This review aimed to summarize the health benefits of T3, particularly in prevention or treatment of non-communicable diseases (NCDs), including cardiovascular, musculoskeletal, metabolic, gastric, and skin disorders, as well as cancers. Studies showed that T3 could prevent various NCDs, by suppressing 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) in the mevalonate pathway, inflammatory response, oxidative stress, and alternating hormones. The efficacy of T3 in preventing/treating these NCDs is similar or greater compared to tocopherol (TF). TF may lower the efficacy of T3 because the efficacy of the combination of TF and T3 was lower than T3 alone in some studies. Data investigating the effects of T3 on osteoporosis, arthritis, and peptic ulcers in human are limited. The positive outcomes of T3 treatment obtained from the preclinical studies warrant further validation from clinical trials.

Circulating HOXA9-methylated tumour DNA: A novel biomarker of response to poly (ADP-ribose) polymerase inhibition in BRCA-mutated epithelial ovarian cancer

AIM

Poly (ADP-ribose) polymerase (PARP) inhibitors have emerged as a novel treatment option in BRCA-mutated ovarian cancer (OC); however, responses are variable and there is a lack of prognostic and predictive biomarkers. We therefore investigated whether homeobox A9 (HOXA9) promoter methylation in circulating tumour DNA (meth-ctDNA) can serve as a biomarker in patients with platinum-resistant BRCA-mutated OC, undergoing treatment with a PARP inhibitor.

METHODS

Patients (n = 32) were enrolled as part of a phase II trial testing veliparib in platinum-resistant BRCA-mutated OC. HOXA9 meth-ctDNA was determined at baseline and just before each treatment cycle using digital droplet polymerase chain reaction. Methylation status and change in methylation compared with baseline were correlated with overall survival (OS) and progression-free survival (PFS).

RESULTS

Detection of HOXA9 meth-ctDNA during treatment with a PARP inhibitor was associated with worse clinical outcomes. This association was apparent after the first cycle of treatment and maintained throughout treatment. After three treatment cycles, patients with detectable HOXA9 meth-ctDNA had a median PFS of 5.1 months compared with 8.3 months for patients without, and a median OS of 9.5 months compared with 19.4 months (p < 0.0001 and p = 0.002, respectively). Patients with detectable HOXA9 meth-ctDNA at baseline, but subsequent undetectable levels, had the most favourable clinical outcome, followed by patients with undetectable levels throughout. These associations were maintained in multivariate analysis.

CONCLUSIONS

Longitudinal monitoring of HOXA9 meth-ctDNA is clinically feasible and is strongly correlated to clinical outcomes (PFS, OS), suggesting that it may serve as a valuable predictive biomarker to inform clinical decision-making in the setting of platinum-resistant BRCA-mutated OC treated with a PARP inhibitor.

Interplay Between MicroRNAs and Oxidative Stress in Ovarian Conditions with a Focus on Ovarian Cancer and Endometriosis

Ovarian cancer and endometriosis are two distinct gynaecological conditions that share many biological aspects incuding proliferation, invasion of surrounding tissue, inflammation, inhibition of apoptosis, deregulation of angiogenesis and the ability to spread at a distance. miRNAs are small non-coding RNAs (19–22 nt) that act as post-transcriptional modulators of gene expression and are involved in several of the aforementioned processes. In addition, a growing body of evidence supports the contribution of oxidative stress (OS) to these gynaecological diseases: increased peritoneal OS due to the decomposition of retrograde menstruation blood facilitates both endometriotic lesion development and fallopian tube malignant transformation leading to high-grade serous ovarian cancer (HGSOC). Furthermore, as HGSOC develops, increased OS levels are associated with chemoresistance. Finally, continued bleeding within ovarian endometrioma raises OS levels and contributes to the development of endometriosis-associated ovarian cancer (EAOC). Therefore, this review aims to address the need for a better understanding of the dialogue between miRNAs and oxidative stress in the pathophysiology of ovarian conditions: endometriosis, EAOC and HGSOC.