A Phase 3 Randomized Trial of Nicotinamide for Skin-Cancer Chemoprevention

Use of nicotinamide in dermatology

Nicotinamide (niacinamide) is the water-soluble, amide form of vitamin B3. We review the evidence underlying the use of nicotinamide for various dermatological indications, including nonmelanoma cancer prophylaxis, blistering disorders, acne vulgaris and cosmetic indications, and speculate upon its future role in dermatological practice.

Current challenges in photoprotection

Electromagnetic radiation in the ultraviolet, visible, and infrared ranges all produce biologic effects. Ultraviolet filters are the most well-studied photoprotective measure for the adverse effects of ultraviolet radiation. Because of the reported endocrinologic effects of oxybenzone in animal studies, its effects on coral reefs, and its photocontact allergy potential, its use has been minimized in many countries worldwide. New developments in topical antioxidants and oral and subcutaneous agents (eg, Polypodium leucotomos extract, afamelanotide, nicotinamide) with photoprotective and antiphotocarcinogenic properties could potentially provide addition modalities for protection against the effects of visible light and infrared radiation.

More than skin deep? Potential nicotinamide treatment applications in chronic kidney transplant recipients

Non-melanoma cutaneous carcinomas, or skin cancers, predominantly squamous cell carcinomas (SCCs), are the most common malignancies occurring in kidney transplant recipients (KTRs). Squamous cell carcinoma risk is dramatically elevated in KTRs, occurring at rates of up 45-250 times those reported in general populations. New non-melanoma skin cancers in KTRs with a prior non-melanoma skin cancer also develop at 3-times the rate reported in non-KTRs with the same clinical history. The unique aggressiveness of SCCs in KTRs increases patient morbidity, due to the high rate of new lesions requiring treatment, frequently surgical excision. Oral nicotinamide shows promise in the chemoprevention of the especially aggressive non-melanoma skin cancers which occur in KTRs. This benefit might be conferred via its inhibition of sirtuin enzymatic pathways. Nicotinamide’s concurrent hypophosphatemic effect may also partially ameliorate the disturbed calcium-phosphorus homeostasis in these patients-a putative risk factor for mortality, and graft failure. Conceivably, a phase 3 trial of nicotinamide for the prevention of non-melanoma skin cancers in KTRs, lasting at least 12-mo, could also incorporate imaging and laboratory measures which assess nicotinamide’s impact on subclinical cardiovascular and chronic kidney disease risk, and progression.

Primary and Secondary Chemoprevention of Malignant Melanoma

The incidence of malignant melanoma (MM) continues to rise in the United States. While sun protection and full body skin examinations remain the mainstay of preventative care, chemoprevention of the deadly disease has become an increasingly popular field of study. In this focused review, we discuss current findings and analyze the risks and benefits of various agents investigated for the primary and secondary chemoprevention of MM. Such agents include topical retinoids, vitamins, and supplements, Polypodium leucotomas extracts, non-steroidal anti-inflammatory agents (NSAIDs), statins, sunscreens, and field therapy with topical imiquimod for primary and secondary chemoprevention. We further identify a need for expanded high quality human research on the topic.

N-methyl-2-pyridone-5-carboxamide (2PY)-Major Metabolite of Nicotinamide: An Update on an Old Uremic Toxin

N-methyl-2-pyridone-5-carboxamide (2PY, a major metabolite of nicotinamide, NAM) was recently identified as a uremic toxin. Recent interventional trials using NAM to treat high levels of phosphorus in end-stage renal disease have highlighted new potential uremic toxicities of 2PY. In the context of uremia, the accumulation of 2PY could be harmful-perhaps by inhibiting poly (ADP-ribose) polymerase-1 activity. Here, we review recently published data on 2PY's metabolism and toxicological profile.

NNMT Silencing Activates Tumor Suppressor PP2A, Inactivates Oncogenic STKs, and Inhibits Tumor Forming Ability

Purpose: To identify potential molecular hubs that regulate oncogenic kinases and target them to improve treatment outcomes for glioblastoma patients.Experimental Design: Data mining of The Cancer Genome Atlas datasets identified nicotinamide-N-methyl transferase (NNMT) as a prognostic marker for glioblastoma, an enzyme linked to the reorganization of the methylome. We tested our hypothesis that NNMT plays a crucial role by modulating protein methylation, leading to inactivation of tumor suppressors and activation of oncogenes. Further experiments were performed to understand the underlying biochemical mechanisms using glioblastoma patient samples, established, primary, and isogenic cells.Results: We demonstrate that NNMT outcompetes leucine carboxyl methyl transferase 1 (LCMT1) for methyl transfer from principal methyl donor SAM in biological systems. Inhibiting NNMT increased the availability of methyl groups for LCMT1 to methylate PP2A, resulting in the inhibition of oncogenic serine/threonine kinases (STK). Further, NNMT inhibition retained the radiosensitizer nicotinamide and enhanced radiation sensitivity. We have provided the biochemical rationale of how NNMT plays a vital role in inhibiting tumor suppressor PP2A while concomitantly activating STKs.Conclusions: We report the intricate novel mechanism in which NNMT inhibits tumor suppressor PP2A by reorganizing the methylome both at epigenome and proteome levels and concomitantly activating prosurvival STKs. In glioblastoma tumors with NNMT expression, activation of PP2A can be accomplished by FDA approved perphenazine (PPZ), which is currently used to treat mood disorders such as schizophrenia, bipolar disorder, etc. This study forms a foundation for further glioblastoma clinical trials using PPZ with standard of care treatment. Clin Cancer Res; 23(9); 2325-34. ©2016 AACR.

[What is new in basal cell carcinoma?]

BACKGROUND

Basal cell carcinoma (BCC) is the most common skin cancer in fair-skinned individuals. Although lymph node or visceral metastases are observed in less than 0.5 % of all cases, BCC can have a fatal course due to its highly invasive growth pattern.

OBJECTIVES

To provide a comprehensive update on diagnosis, treatment, and prevention of BCC.

MATERIALS AND METHODS

We review the current literature and recommendations of the German guidelines on treatment and prevention of skin cancer. The most pertinent developments are summarized in this review article.

RESULTS

The use of optical coherence tomography and reflectance confocal microscopy can significantly improve the diagnosis of BCC compared with clinical assessment and dermoscopy alone. Mohs micrographic surgery remains the therapeutic gold standard for tumors in the head and facial area and tumors with high-risk features. The application of imiquimod, 5‑fluorouracil, or photodynamic therapy should be restricted to low-risk superficial tumors. Topical inhibitors of the sonic hedgehog (SHH) pathway are currently being evaluated in early clinical trials. In contrast, vismodegib and sonidegib have been approved for the systemic treatment of locally advanced and metastatic BCC with good response rates. The most common adverse events of both agents are muscle cramps, dysgeusia, diffuse alopecia, weight loss, and fatigue. In an Australian phase III trial, oral nicotinamide (vitamin B3) reduced the occurrence of new BCC by 20 % in skin cancer patients.

CONCLUSIONS

Targeted therapy with SHH inhibitors has improved the prognosis of locally advanced and metastatic BCC, albeit at the cost of a significant number of adverse events.

Transforming Cancer Prevention through Precision Medicine and Immune-oncology

We have entered a transformative period in cancer prevention (including early detection). Remarkable progress in precision medicine and immune-oncology, driven by extraordinary recent advances in genome-wide sequencing, big-data analytics, blood-based technologies, and deep understanding of the tumor immune microenvironment (TME), has provided unprecedented possibilities to study the biology of premalignancy. The pace of research and discovery in precision medicine and immunoprevention has been astonishing and includes the following clinical firsts reported in 2015: driver mutations detected in circulating cell-free DNA in patients with premalignant lesions (lung); clonal hematopoiesis shown to be a premalignant state; molecular selection in chemoprevention randomized controlled trial (RCT; oral); striking efficacy in RCT of combination chemoprevention targeting signaling pathway alterations mechanistically linked to germline mutation (duodenum); molecular markers for early detection validated for lung cancer and showing promise for pancreatic, liver, and ovarian cancer. Identification of HPV as the essential cause of a major global cancer burden, including HPV16 as the single driver of an epidemic of oropharyngeal cancer in men, provides unique opportunities for the dissemination and implementation of public health interventions. Important to immunoprevention beyond viral vaccines, genetic drivers of premalignant progression were associated with increasing immunosuppressive TME; and Kras vaccine efficacy in pancreas genetically engineered mouse (GEM) model required an inhibitory adjuvant (Treg depletion). In addition to developing new (e.g., epigenetic) TME regulators, recent mechanistic studies of repurposed drugs (aspirin, metformin, and tamoxifen) have identified potent immune activity. Just as precision medicine and immune-oncology are revolutionizing cancer therapy, these approaches are transforming cancer prevention. Here, we set out a brief agenda for the immediate future of cancer prevention research (including a "Pre-Cancer Genome Atlas" or "PCGA"), which will involve the inter-related fields of precision medicine and immunoprevention - pivotal elements of a broader domain of personalized public health.

Chemoprevention of Keratinocyte Carcinomas: An Updated Review

A well-established link between ultraviolet exposure and the carcinogenesis of keratinocyte carcinomas exists. Despite increased sun protection efforts, skin cancer remains the most common cancer in the USA. Numerous studies on the topic of chemoprevention investigate alternative topical, oral, and injectable agents to reduce skin cancer incidence in those at risk. Such agents include sunscreen, numerous vitamins and minerals, difluoromethylornithine, non-steroidal anti-inflammatory drugs, various peptides, field therapy, statins, and polyphenols. In this focused review, we discuss the risks and benefits of chemoprotective agents reported in clinical studies conducted in humans. We report several agents that may reduce skin cancer incidence in those at risk.

Nicotinamide Suppresses the DNA Damage Sensitivity of Saccharomyces cerevisiae Independently of Sirtuin Deacetylases

Nicotinamide is both a reaction product and an inhibitor of the conserved sirtuin family of deacetylases, which have been implicated in a broad range of cellular functions in eukaryotes from yeast to humans. Phenotypes observed following treatment with nicotinamide are most often assumed to stem from inhibition of one or more of these enzymes. Here, we used this small molecule to inhibit multiple sirtuins at once during treatment with DNA damaging agents in the Saccharomyces cerevisiae model system. Since sirtuins have been previously implicated in the DNA damage response, we were surprised to observe that nicotinamide actually increased the survival of yeast cells exposed to the DNA damage agent MMS. Remarkably, we found that enhanced resistance to MMS in the presence of nicotinamide was independent of all five yeast sirtuins. Enhanced resistance was also independent of the nicotinamide salvage pathway, which uses nicotinamide as a substrate to generate NAD+, and of a DNA damage-induced increase in the salvage enzyme Pnc1 Our data suggest a novel and unexpected function for nicotinamide that has broad implications for its use in the study of sirtuin biology across model systems.

Comparison of the effects of nicotinic acid and nicotinamide degradation on plasma betaine and choline levels

AIM

The present study was to compare the effects of nicotinic acid and nicotinamide on the plasma methyl donors, choline and betaine.

METHODS

Thirty adult subjects were randomly divided into three groups of equal size, and orally received purified water (C group), nicotinic acid (300 mg, NA group) or nicotinamide (300 mg, NM group). Plasma nicotinamide, N¹-methylnicotinamide, homocysteine, betaine and choline levels before and 1.5-h and 3-h post-dosing, plasma normetanephrine and metanephrine concentrations at 3-h post-dosing, and the urinary excretion of N¹-methyl-2-pyridone-5-carboxamide during the test period were examined.

RESULTS

The level of 3-h plasma nicotinamide, N¹-methylnicotinamide, homocysteine, the urinary excretion of N¹-methyl-2-pyridone-5-carboxamide and pulse pressure (PP) in the NM group was 221%, 3972%, 61%, 1728% and 21.2% higher than that of the control group (P < 0.01, except homocysteine and PP P < 0.05), while the 3-h plasma betaine, normetanephrine and metanephrine level in the NM group was 24.4%, 9.4% and 11.7% lower (P < 0.05, except betaine P < 0.01), without significant difference in choline levels. Similar but less pronounced changes were observed in the NA group, with a lower level of 3-h plasma N¹-methylnicotinamide (1.90 ± 0.20 μmol/l vs. 3.62 ± 0.27 μmol/l, P < 0.01) and homocysteine (12.85 ± 1.39 μmol/l vs. 18.08 ± 1.02 μmol/l, P < 0.05) but a higher level of betaine (27.44 ± 0.71 μmol/l vs. 23.52 ± 0.61 μmol/l, P < 0.05) than that of the NM group.

CONCLUSION

The degradation of nicotinamide consumes more betaine than that of nicotinic acid at identical doses. This difference should be taken into consideration in niacin fortification.

Natural Products for Cancer Prevention: Clinical Update 2016

OBJECTIVES

To present a clinical update of natural products for cancer prevention and provide oncology nurses with an evidence-based review of natural products for patient counseling and education.

DATA SOURCES

Clinical trials published in PubMed.

CONCLUSION

In the past 4 years since the publication of the original review there have been minimal changes in the conclusions of the published literature on the use of natural products for cancer prevention. To date, clinical trials have not demonstrated conclusive benefit of using natural products for cancer prevention, and current guidelines do not recommend their use. This review provides an update on published and ongoing trials and can serve as an updated resource for nurses. Evidence-based natural products databases can help nurses stay current with the scientific literature and be effective educators and health coaches for their patients, who can be influenced by marketing of unregulated products.

IMPLICATIONS FOR NURSING PRACTICE

Patients often discuss the use of natural products with nurses. Nurses have an opportunity to educate and coach patients in effective preventive lifestyle practices.

1-methylnicotinamide and its structural analog 1,4-dimethylpyridine for the prevention of cancer metastasis

Background

1-methylnicotinamide (1-MNA), an endogenous metabolite of nicotinamide, has recently gained interest due to its anti-inflammatory and anti-thrombotic activities linked to the COX-2/PGI₂ pathway. Given the previously reported anti-metastatic activity of prostacyclin (PGI₂), we aimed to assess the effects of 1-MNA and its structurally related analog, 1,4-dimethylpyridine (1,4-DMP), in the prevention of cancer metastasis.

Methods

All the studies on the anti-tumor and anti-metastatic activity of 1-MNA and 1,4-DMP were conducted using the model of murine mammary gland cancer (4T1) transplanted either orthotopically or intravenously into female BALB/c mouse. Additionally, the effect of the investigated molecules on cancer cell-induced angiogenesis was estimated using the matrigel plug assay utilizing 4T1 cells as a source of pro-angiogenic factors.

Results

Neither 1-MNA nor 1,4-DMP, when given in a monotherapy of metastatic cancer, influenced the growth of 4T1 primary tumors transplanted orthotopically; however, both compounds tended to inhibit 4T1 metastases formation in lungs of mice that were orthotopically or intravenously inoculated with 4T1 or 4T1-luc2-tdTomato cells, respectively. Additionally, while 1-MNA enhanced tumor vasculature formation and markedly increased PGI₂ generation, 1,4-DMP did not have such an effect. The anti-metastatic activity of 1-MNA and 1,4-DMP was further confirmed when both agents were applied with a cytostatic drug in a combined treatment of 4T1 murine mammary gland cancer what resulted in up to 80 % diminution of lung metastases formation.

Conclusions

The results of the studies presented below indicate that 1-MNA and its structural analog 1,4-DMP prevent metastasis and might be beneficially implemented into the treatment of metastatic breast cancer to ensure a comprehensive strategy of metastasis control.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-016-0389-9) contains supplementary material, which is available to authorized users.

Is early detection of basal cell carcinoma worthwhile? Systematic review based on the WHO criteria for screening

The incidence of basal cell carcinoma (BCC) has risen three- to fourfold over the last 30 years and is expected to continue to increase with ageing of the population. Although BCC has a good prognosis, it causes significant morbidity and has an important impact on the public health budget due to direct treatment costs. Based on the existing evidence, a systematic evaluation of the World Health Organization criteria was performed to determine whether earlier detection of BCC could reduce morbidity and cost. BCC slowly increases in size, with a median increase in diameter of 0·5 mm over 10 weeks. There is an important delay in diagnosis ranging from 19 to 25 months. In several studies BCC size was the main determinant of treatment cost, surgical complexity, reconstruction technique and the specific surgical procedure performed, such as Mohs micrographic surgery or surgical excision. One study showed that size also seems to affect the cost per treatment for other nonsurgical options. The use of vismodegib, an inhibitor of the hedgehog pathway, is confined to locally advanced or metastatic BCC. Delays in diagnosis and appropriate treatment are the most important underlying causes in the occurrence of giant BCC and/or BCC with metastasis. Although the latter represent only a very small fraction of all BCCs, the majority of them are located in the facial region. The available data point to a slow increase in the size of BCCs over time. Size is one of the major determinants in choice of treatment and the associated cost, especially for facial BCC. Therefore we conclude that current data support early detection and adequate management of BCCs on the face.

Efficient Synthesis of Nicotinamide-1-¹⁵N for Ultrafast NMR Hyperpolarization Using Parahydrogen

Nicotinamide (a vitamin B₃ amide) is one of the key vitamins as well as a drug for treatment of M. tuberculosis, HIV, cancer, and other diseases. Here, an improved Zincke reaction methodology is presented allowing for straightforward and scalable synthesis of nicotinamide-1-¹⁵N with an excellent isotopic purity (98%) and good yield (55%). ¹⁵N nuclear spin label in nicotinamide-1-¹⁵N can be NMR hyperpolarized in seconds using parahydrogen gas. NMR hyperpolarization using the process of temporary conjugation between parahydrogen and to-be-hyperpolarized biomolecule on hexacoordinate iridium complex via the Signal Amplification By Reversible Exchange (SABRE) method significantly increases detection sensitivity (e.g., >20 000-fold for nicotinamide-1-¹⁵N at 9.4 T) as has been shown by Theis T. et al. (J. Am. Chem. Soc.2015, 137, 1404), and hyperpolarized in this fashion, nicotinamide-1-¹⁵N can be potentially used to probe metabolic processes in vivo in future studies. Moreover, the presented synthetic methodology utilizes mild reaction conditions, and therefore can also be potentially applied to synthesis of a wide range of ¹⁵N-enriched N-heterocycles that can be used as hyperpolarized contrast agents for future in vivo molecular imaging studies.

A Model to Predict the Risk of Keratinocyte Carcinomas

Basal cell and squamous cell carcinomas of the skin are the commonest cancers in humans, yet no validated tools exist to estimate future risks of developing keratinocyte carcinomas. To develop a prediction tool, we used baseline data from a prospective cohort study (n = 38,726) in Queensland, Australia, and used data linkage to capture all surgically excised keratinocyte carcinomas arising within the cohort. Predictive factors were identified through stepwise logistic regression models. In secondary analyses, we derived separate models within strata of prior skin cancer history, age, and sex. The primary model included terms for 10 items. Factors with the strongest effects were >20 prior skin cancers excised (odds ratio 8.57, 95% confidence interval [95% CI] 6.73-10.91), >50 skin lesions destroyed (odds ratio 3.37, 95% CI 2.85-3.99), age ≥ 70 years (odds ratio 3.47, 95% CI 2.53-4.77), and fair skin color (odds ratio 1.75, 95% CI 1.42-2.15). Discrimination in the validation dataset was high (area under the receiver operator characteristic curve 0.80, 95% CI 0.79-0.81) and the model appeared well calibrated. Among those reporting no prior history of skin cancer, a similar model with 10 factors predicted keratinocyte carcinoma events with reasonable discrimination (area under the receiver operator characteristic curve 0.72, 95% CI 0.70-0.75). Algorithms using self-reported patient data have high accuracy for predicting risks of keratinocyte carcinomas.