Effect of Simultaneous Administration of Dihydroxyacetone on the Diffusion of Lawsone Through Various In Vitro Skin Models.

Unprotected sunlight exposure is a risk factor for a variety of cutaneous cancers. Topically used dihydroxyacetone (DHA) creates, via Maillard reaction, chemically fixed keratin sunscreen in the stratum corneum with significant protection against UVA/Soret radiation. When used in conjunction with naphthoquinones a naphthoquinone-modified DHA Maillard reaction is produced that provides protection across the UVB/UVA/Soret spectra lasting up to 1 week, resisting sweating and contact removal. The aim of this study was to examine a simplified version of this formulation for effect on UV transmission and to determine if penetration levels merit toxicity concerns. Permeability was demonstrated for freshly prepared DHA (30 mg/mL) and lawsone (0.035 mg/mL) alone and in combination using a side-by-side diffusion apparatus at 37°C over 48 h across shed snake skin and dermatomed pig skin. These samples were then examined for effectiveness and safety. Concentrations were determined by HPLC and UPLC monitored from 250-500 nm. Lawsone flux significantly decreased across pig skin (20.8 (± 4.8) and 0.09 (± 0.1) mg/cm(2) h without and with DHA, respectively) but did not change across shed snake skin in the presence of DHA. Significantly reduced lawsone concentration was noted in donor chambers of combined solutions. Damage was not observed in any skins. Darker coloration with greater UV absorbance was observed in skins exposed to the combined solution versus individual solutions. This study confirmed that combined DHA and lawsone provided effective blocking of ultraviolet light through products bound in keratinized tissue. DHA permeation levels in pig skin suggest further in vitro and in vivo study is required to determine the safety of this system.

Do melanoidins induced by topical 9% dihydroxyacetone sunless tanning spray inhibit vitamin d production? A pilot study.

We report here preliminary pilot study data of the effect of sunless tanning spray with 9% [Correction added after online publication (August 24th, 2009): The concentration of Dihydroxyacetone used in the study was 9% and not 3% as previously stated] dihydroxyacetone (DHA) on 25-hydroxyvitamin D [25(OH)D] serum levels in subjects exposed to controlled amounts of UV-B radiation during April/May in Omaha, NE, 41 degrees N latitude. We found that DHA-induced melanoidins in skin act as a topical sunscreen attenuating the formation of 25(OH)D.

Pancreatic cancer and the FAMMM syndrome.

Hereditary cancer syndromes provide excellent models for molecular genetic studies that may aid significantly in case detection, surveillance, and management. Ultimately, molecularly based designer pharmaceuticals may emerge from this research, such as the case of trastuzumab (Herceptin) in HER-2/neu positive breast cancer, and imatinib (Gleevec) in chronic myelocytic leukemia and gastrointestinal stromal tumors. Importantly, these molecular findings may fuel significant clues to cancer control. This background is mentioned since surveillance and management of pancreatic cancer, a major concern of this manuscript, has been uniformly unsuccessful as evidenced by the close correspondence between its incidence and its mortality. Yet knowledge about its genetic and molecular pathology will hopefully ameliorate this vexing problem. One molecular genetic clue is the recently identified palladin mutation in two pancreatic cancer prone families. However, caution must be used toward the palladin mutation, as several recent publications have questioned its significance as a pancreatic cancer causing mutation. We provide a concise description of pancreatic cancer in concert with malignant melanoma in the familial atypical multiple mole melanoma (FAMMM) syndrome as a potential preventive model. This knowledge should help clinicians and basic scientists seize on the opportunity to develop more sensitive and specific screening and management programs in this disease; while a relatively small subset of pancreatic cancer may be readily identifiable through its FAMMM phenotype, coupled with its CDKN2A mutation, this hereditary disorder, given a keen knowledge of its natural history and molecular genetics, may prove to be an effective clinical preventive model.

Hereditary cancer syndrome diagnosis: molecular genetic clues and cancer control.

Oncologists who are aware of the progress in hereditary cancer syndrome diagnosis, and, in particular, of how this effort may be effectively facilitated through a comprehensive family history in concert with molecular genetic studies, are in the envious position of designing highly targeted screening and management programs for the membership of these cancer-prone families. The Lynch syndrome is discussed as a clinical model wherein the presence of mismatch repair mutations provides a high level of diagnostic certainty for the initiation of targeted cancer screening and management. The familial atypical multiple mole melanoma-pancreatic cancer (FAMMM-PC) syndrome, on the other hand, provides another model with cancer-control potential. Given its phenotypic features of multiple atypical nevi, high total body mole count and cutaneous malignant melanoma, coupled with the integral association of PC in a subset of FAMMM kindreds with the CDKN2A germline mutation, this may result in a perhaps lower level of diagnostic certainty when compared with the Lynch syndrome. This knowledge may impact upon progress in the earlier diagnosis of melanoma and provide an impetus for creative diagnostic methods in PC, a disease that, at this time, demonstrates a mortality rate virtually identical to its incidence rate.

Sebaceous skin lesions as clues to hereditary non-polyposis colorectal cancer.

Cutaneous lesions consonant with Muir-Torre syndrome strongly suggest hereditary non-polyposis colorectal cancer (HNPCC). Ponti et al. discuss the importance of combining molecular genetic features of the sebaceous neoplasms, including microsatellite instability and immunohistochemistry, with family history, to determine the likelihood of HNPCC. Proof of diagnosis is identification of one of the mismatch repair germline mutations.

The maillard reaction for sunlight protection.

During seven months of a clinical trial in spring, summer, and fall, 30 UVA/B/Soret band-photosensitive patients used sequential topical applications of dihydroxyacetone (DHA) followed by naphthoquinone only at bedtime and received excellent photoprotection without a single therapeutic failure or loss of any patient to follow-up. Eighteen of the 30 patients extended the limits of their photoprotection repeatedly over a seven-month period to tolerate without sunburns six to eight hours of midday sunlight under all kinds of occupational and recreational environmental conditions. Previously, the use of 3% DHA topically in earlier studies gave only a sun protection factor (SPF) of 3. In this reanalysis of the original notes of a previous clinical study of the melanoidins produced by DHA followed by naphthoquinone in the keratin layers of the epidermis of minimally pigmented Caucasian photosensitive patients, it is determined that these patients received a minimal UVB photoprotection of SPF 18 or more. This represents at least a sixfold amplification of the UVB photoprotective effect over the use of only dihydroxyacetone in the Maillard reaction.

Germline splicing mutations of CDKN2A predispose to melanoma.

Coding mutations of the CDKN2A gene on chromosome 9p21 cosegregate with 25-60% of familial melanoma cases, but there remains a number of 9p21-linked kindreds that lack germline coding mutations of CDKN2A. We sequenced CDKN2A exons 1alpha, 2, 3, and the adjacent intronic regions in 167 melanoma-prone families (at least two affected first-degree relatives), and detected four splice site variations, three of which cosegregate with the disease. RT-PCR experiments verified that these three variants, including an AGgt to ATgt mutation that demonstrates a founder effect, do affect splicing. While an exon 1alpha splice donor site mutation incompletely abolishes splicing, the correctly spliced mRNA yields a protein (Q50P) that cannot effectively interact with CDK4. We also performed RT-PCR on mRNA from 16 melanoma-prone kindreds to search for cryptic splice sites deep within introns, but identified no splice variants. Meanwhile, we screened 139 affected families using allele-specific PCR for the recently discovered IVS2-105A>G mutation, but found only one family that possesses this alteration. We conclude that splice site mutations do predispose to disease in a subset of melanoma-prone kindreds. Characterization of additional splice site variants and other noncoding alterations of CDKN2A should allow us to detect a wider range of mutations in at-risk patients.

Hereditary factors in pancreatic cancer.

The incidence and the mortality rates for pancreatic cancer are the same, indicating its dismal outlook. Its natural history remains elusive. Cigarette smoking appears to be the most significant environmental culprit. Hereditary factors may account for approximately 5% of the total pancreatic cancer burden. However, when its extant heterogeneity and the reduced penetrance of causal germline mutations are considered, the hereditary incidence may significantly exceed this estimate. Even when endoscopic ultrasound (EUS), the gold standard for pancreatic cancer screening, is utilized, early detection with surgical cure has rarely been accomplished. Needed to ameliorate this problem is research into genetic and environmental risk factors and their interaction. The identification of tumor biomarkers which signal early pathogenetic events, thereby enabling pancreatic cancer to be diagnosed at its earliest possible stage before it has spread to regional lymph nodes or to more distant sites, will improve the outlook. We discuss our research approaches to this problem. Members of families with the p16 germline mutation will undergo EUS coupled with the collection of pancreatic juice for the study of a possible gradient for telomerase activity, K- ras mutations, and cytology. If changes in these putative biomarkers are observed, endoscopic retrograde cholangiopancreatography (ERCP) would be the next diagnostic step. We conclude with a discussion of ethical concerns about this research.

Phenotypic variation in eight extended CDKN2A germline mutation familial atypical multiple mole melanoma-pancreatic carcinoma-prone families: the familial atypical mole melanoma-pancreatic carcinoma syndrome.

BACKGROUND: Hereditary pancreatic carcinoma shows extant phenotypic and genotypic heterogeneity as evidenced by its integral association with a variety of hereditary cancer syndromes inclusive of the familial atypical multiple mole melanoma (FAMMM) syndrome in concert with CDKN2A (p16) germline mutations. METHODS: Creighton University's familial pancreatic carcinoma resource comprises 159 families of which 19 (12%) show the FAMMM cutaneous phenotypes. The authors describe eight families with the FAMMM-pancreatic carcinoma (FAMMM-PC) association in concert with a CDKN2A germline mutation. Each family was thoroughly educated about all facets of the study, including the molecular genetics, reduced penetrance of CDKN2A mutations, and their variable expressivity. Genetic counseling was provided to each patient. RESULTS: Diversity in cancer presentation within and among the families was noteworthy, wherein melanoma predominated in certain of the families whereas pancreatic carcinoma predominated in others. Early-onset pancreatic carcinoma (at ages 35, 45, 46, and 49 years) appeared in some of the families whereas markedly later-onset pancreatic carcinoma occurred in others. There were four incidences of melanoma and pancreatic carcinoma as double primaries in the same individuals. One patient with melanoma and pancreatic carcinoma had a third primary of breast carcinoma. Another patient had sarcoma, esophageal carcinoma, and two melanoma primaries, whereas his daughter had sarcoma and was a carrier of a CDKN2A mutation. CONCLUSIONS: The authors suggest that these tumors may collectively, in concert with CDKN2A mutations, constitute a "new" putative hereditary carcinoma syndrome referred to as FAMMM-PC. More clinical and molecular genetic research on additional families with pancreatic carcinoma in concert with the FAMMM will be required.