Heme oxygenase 1 (HO-1) is a detoxifying antioxidant microsomal enzyme that regulates inflammation, apoptosis, cell proliferation, and angiogenesis in prostate cancer (PCa). This makes HO-1 a promising target for therapeutic prevention and treatment due to its anti-inflammatory properties and ability to control redox homeostasis. Clinical evidence highlights the possible correlation between HO-1 expression and PCa growth, aggressiveness, metastasized tumors, resistance to therapy, and poor clinical outcomes. Interestingly, studies have reported anticancer benefits mediated by both HO-1 induction and inhibition in PCa models. Contrasting evidence exists on the role of HO-1 in PCa progression and possible treatment targets. Herein, we provide an overview of available evidence on the clinical significance of HO-1 signaling in PCa. It appears that the beneficial effects of HO-1 induction or inhibition are dependent on whether it is a normal versus malignant cell as well as the intensity (major vs. minor) of the increase in HO-1 enzymatic activity. The current literature evidence indicates that HO-1 has dual effects in PCa. The amount of cellular iron and reactive oxygen species (ROS) can determine the role of HO-1 in PCa. A major increase in ROS enforces HO-1 to a protective role. HO-1 overexpression may provide cryoprotection to normal cells against oxidative stress via suppressing the expression of proinflammatory genes, and thus offer therapeutic prevention. In contrast, a moderate increase in ROS can lead to the perpetrator role of HO-1, which is associated with PCa progression and metastasis. HO-1 inhibition by xenobiotics in DNA-damaged cells tilts the balance to promote apoptosis and inhibit PCa proliferation and metastasis. Overall, the totality of the evidence revealed that HO-1 may play a dual role in the therapeutic prevention and treatment of PCa.

Introduction: The epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) in combination with anti-vascular endothelial growth factor receptor (VEGFR) agents have shown improved survival outcomes in recent studies. However, its efficacy related to survival outcomes as a first- or second-line agent and based on generations remains to be explored. This study estimated the survival outcomes of EGFR-TKIs plus anti-VEGFR in combination in defined populations of advanced non-small cell lung cancer (NSCLC) patients overall, as a first- or second line of treatment, with different generations of EGFR-TKIs and EGFR-TKIs plus bevacizumab combination as a subgroup. Methods: A literature search was conducted using PubMed, SCOPUS, Cochrane Library, and ClinicalTrials.gov databases through June 2023 to identify primary research reporting the survival outcomes of EGFR-TKIs in combination with anti-VEGFR agents in patients with advanced NSCLC. Studies that were single-arm, published in non-English languages, and had missing data on survival outcomes were excluded. A meta-analysis was conducted to generate pooled hazard ratios (HRs) with 95% confidence intervals (CI) for overall survival (OS) and progression-free survival (PFS). Methodological quality and risk of bias in studies were assessed using the Cochrane Handbook for Systematic Reviews of Interventions risk of bias tool. Results: A total of 20 randomized controlled trials were included in the qualitative synthesis, and 11 (2182 participants) were included in the meta-analysis. Patients’ median age ranged from 58 to 68 years; 36% to 70% of patients were female; most of them had IIIa/b to IV stage cancer. In meta-analyses, the EGFR-TKIs plus anti-VEGFR combination resulted in improved PFS (HR, 0.73; 95% CI: 0.61, 0.86; p < 0.00001) in patients with advanced NSCLC but had no impact on OS (HR, 0.93; 95% CI: 0.79, 1.10; p = 0.41). The first line of treatment and first-generation EGFR-TKIs with the combination also improved the PFS (HR, 0.64; 95% CI: 0.57, 0.71; p < 0.00001; HR, 0.63; 95% CI: 0.56, 0.71; p < 0.00001) respectively, however, had no impact on OS. Conclusions: Our meta-analysis indicated EGFR-TKIs with anti-VEGFR in combination not only improved overall PFS but also showed similar results to a first line and first-generation agent compared to EGFR-TKI alone.

Vitamin D is a promising anticancer agent for the prevention and treatment of several cancers, including melanoma. Low 25-hydroxyvitamin D levels, a routinely used marker for vitamin D, have been suggested as one of the factors in the development and progression of melanoma. The parent vitamin D needs activation by cytochrome P450 (CYP) enzymes to exert its actions via the vitamin D receptor (VDR). This review discusses the role of vitamin D in melanoma and how CYP-mediated metabolism can potentially affect the actions of vitamin D. Through interacting with the retinoid X receptor, VDR signaling leads to anti-inflammatory, antioxidative, and anticancer actions. Calcitriol, the dihydroxylated form of vitamin D₃, is the most active and potent ligand of VDR. CYP27A1, CYP27B1, and CYP2R1 are involved in the activation of vitamin D, whereas CYP24A1 and CYP3A4 are responsible for the degradation of the active vitamin D. CYP24A1, the primary catabolic enzyme of calcitriol, is overexpressed in melanoma tissues and cells. Several drug classes and natural health products can modulate vitamin D-related CYP enzymes and eventually cause lower levels of vitamin D and its active metabolites in tissues. Although the role of vitamin D in the development of melanoma is yet to be fully elucidated, it has been proposed that melanoma prevention may be significantly aided by increased vitamin D signaling. Furthermore, selective targeting of the catabolic enzymes responsible for vitamin D degradation could be a plausible strategy in melanoma therapy. Vitamin D signaling can be improved by utilizing dietary supplements or by modulating CYP metabolism. A positive association exists between the intake of vitamin D supplements and improved prognosis for melanoma patients. Further investigation is required to determine the function of vitamin D supplementation and specific enzyme targeting in the prevention of melanoma.