Differential Expression of Cancer Testis Antigens on Lentigo Maligna and Lentigo Maligna Melanoma

The cancer/testis antigens (CTA) are a group of antigens expressed on germ cells of healthy testis and malignant tumors. We studied whether CTA are present on lentigo maligna (LM) and LM melanoma (LMM) samples. Immunohistochemical expression of a panel of CTA (MAGE-A1, A2- A3, NY-ESO-1, PRAME, SSX-2, and a MAGE-A antibody reactive with -A1, -A2, -A3, -A4, -A6, -A10, and -A12) was investigated in formalin-fixed paraffin-embedded samples from LMM (n = 20), LM (n = 8), chronically sun-exposed skin (n = 7), and healthy skin (n = 7). In 4 LMM lesions, the MAGE-A marker was positive. Another 3 LMM lesions were positive for MAGE-A1, MAGE-A2, and MAGE-A3. PRAME was positive in 18/20 LMM and 6/8 LM. We did not find expression of MAGE, NY-ESO-1, or SSX-2 in LM, thereby excluding these CTA as diagnostic markers to discern malignant melanocytes in LM from normal melanocytes. LMM did express MAGE, NY-ESO-1, and SSX-2. If a biopsy from a lesion suspect for LM shows positivity for MAGE, NY-ESO-1, and SSX-2, the lesion may actually be LMM. In contrast, PRAME expression was found in LM at low levels and in LMM at much higher levels, and absent in normal melanocytes. PRAME can potentially be used to discern normal melanocytes from malignant melanocytes.

Expression of cancer/testis antigens in cutaneous melanoma: a systematic review

The cancer/testis antigen (CTA) family is a group of antigens whose expression is restricted to male germline cells of the testis and various malignancies. This expression pattern makes this group of antigens potential targets for immunotherapy. The aim of this study was to create an overview of CTA expressed by melanoma cells at mRNA and protein level. A systematic literature search was performed in Medline (PubMed) and Embase from inception up to and including February 2018. Studies were screened for eligibility by two independent reviewers. A total of 65 full-text articles were included in the final analysis. A total of 48 CTA have been studied in melanoma. Various CTA show different expression rates in primary and metastatic tumours. Of the 48 CTA, the most studied were MAGE-A3, MAGE-A1, NY-ESO-1, MAGE-A4, SSX2, MAGE-A2, MAGE-C1/CT7, SSX1, MAGE-C2/CT10 and MAGE-A12. On average, MAGE-A3 mRNA is present in 36% of primary tumours, whereas metastatic tumours have an expression rate of 55-81%. The same applies to the protein expression rate of MAGE-A3 in primary tumours, which is reported to be at 15-37%, whereas metastatic tumours have a higher expression rate of 25-70%. This trend of increased expression in metastases compared with primary tumours is observed with MAGE-A1, MAGE-A2, MAGE-A4, MAGE-A12 and NY-ESO-1. Many CTA are expressed on melanoma. This review provides an overview of the expression frequency of CTAs in melanoma and may aid in identifying CTA as the therapeutic target for immunotherapy.

Correction of a dominant-negative von Willebrand factor multimerization defect by small interfering RNA-mediated allele-specific inhibition of mutant von Willebrand factor

Essentials Substitution therapy for von Willebrand (VW) disease leaves mutant VW factor (VWF) unhindered. Presence of mutant VWF may negatively affect phenotypes despite treatment. Inhibition of VWF by allele-specific siRNAs targeting single-nucleotide polymorphisms is effective. Allele-specific inhibition of VWF p.Cys2773Ser improves multimerization.

SUMMARY

Background Treatment of the bleeding disorder von Willebrand disease (VWD) focuses on increasing von Willebrand factor (VWF) levels by administration of desmopressin or VWF-containing concentrates. Both therapies leave the production of mutant VWF unhindered, which may have additional consequences, such as thrombocytopenia in patients with VWD type 2B, competition between mutant and normal VWF for platelet receptors, and the potential development of intestinal angiodysplasia. Most cases of VWD are caused by dominant-negative mutations in VWF, and we hypothesize that diminishing expression of mutant VWF positively affects VWD phenotypes. Objectives To investigate allele-specific inhibition of VWF by applying small interfering RNAs (siRNAs) targeting common single-nucleotide polymorphisms (SNPs) in VWF. This approach allows allele-specific knockdown irrespective of the mutations causing VWD. Methods Four SNPs with a high predicted heterozygosity within VWF were selected, and siRNAs were designed against both alleles of the four SNPs. siRNA efficiency, allele specificity and siRNA-mediated phenotypic improvements were determined in VWF-expressing HEK293 cells. Results Twelve siRNAs were able to efficiently inhibit single VWF alleles in HEK293 cells that stably produce VWF. Transient cotransfections of these siRNAs with two VWF alleles resulted in a clear preference for the targeted allele over the untargeted allele for 11 siRNAs. We also demonstrated siRNA-mediated phenotypic improvement of the VWF multimerization pattern of the VWD type 2A mutation VWF p.Cys2773Ser. Conclusions Allele-specific siRNAs are able to distinguish VWF alleles on the basis of one nucleotide variation, and are able to improve a severe multimerization defect caused by VWF p.Cys2773Ser. This holds promise for the therapeutic application of allele-specific siRNAs in dominant-negative VWD.

A systematic review on the role of imiquimod in lentigo maligna and lentigo maligna melanoma: need for standardization of treatment schedule and outcome measures

Lentigo maligna (LM) is an in situ variant of melanoma. Our objective was to systematically review clinical and histological clearance and recurrence rates of imiquimod treatment of LM with emphasis on progression to lentigo maligna melanoma (LMM). PubMed, EMBASE and the Cochrane library were searched from inception to May 2015. Articles were included if they described histologically proven LM treated with imiquimod 5% monotherapy or combined with another topical therapy. Analysed outcomes were clinical and histological clearance, recurrence rates and number of LMM. The quality was assessed using the GRADE-like checklist, and results were reported according to the PRISMA Statement. Twenty-six case reports, 11 retrospective studies, three prospective studies and one randomized controlled trial were included. One case report of poor quality was excluded. Complete clinical clearance was seen in 369 of 471 patients (78.3%). Histological clearance was present in 285 of 370 (77%) patients. LMM was diagnosed in nine (1.8%) patients 3.9 months (range 0-11 months) post-treatment. Univariate multinominal logistic regression showed that 6-7 applications/week had a 6.47 greater odds (P = 0.017) of resulting in complete clinical clearance compared to 1-4 applications/week. An intensity of 6-7 applications/week showed a 8.85 greater odds (P = 0.003) of resulting in histological clearance compared to 1-4 applications. Applying imiquimod >60 times during a treatment period of 12 weeks (range 4-36) showed a 7.75 greater odds (P = 0.001) of resulting in histological clearance compared to <60 total applications. In conclusion, a treatment schedule using imiquimod 6-7 applications per week, with at least 60 applications, shows the greatest odds of complete clinical and histological clearance of LM. Imiquimod is an option for patients unfit for or not willing to undergo surgery or radiotherapy. Nine cases of LM progressed to LMM shortly after treatment. Our hypothesis is that these LMM may have been present before starting imiquimod.

Selective effects of fetal alcohol exposure on rat thymocyte development

The thymoproliferative response to concanavalin A (ConA) following fetal alcohol exposure (FAE) is higher than control (149%) on day 44, is lower than control (64%) by day 51, and normalizes by day 69 (88% of controls). The ontogeny of HLA-Dr and transferrin receptor (CD71) expression in response to anti-CD3 stimulation is similar among the groups, but is distinct from that of ConA proliferation. The ontogeny of glucocorticoid cytoplasmic receptor (GCCR) sites per thymocyte is also different from the ontogeny of the ConA response. The number of GCCR sites rises sharply (2.5-fold) in control rat thymocytes between days 30 and 44, and remains at that level at later time points. By contrast, the number of GCCR sites per FAE thymocytes rises nearly linearly and normalizes by day 72. Our data support the notion that prenatal alcohol exposure significantly alters thymic development and indicates that the relationship between the development of thymocyte functional responses and that of GCCR is more complex than initially hypothesized.

Role of inositol triphosphate isomer formation in type II pneumocyte signal transduction

Adenosine triphosphate (ATP) is a potent agonist of surfactant secretion from type II pneumocytes. The extracellular ATP signal is transduced by both P1- and P2-purinergic pathways, which respectively initiate cyclic adenosine monophosphate formation and phosphatidyl inositol hydrolysis to inositol phosphates (Ins P). We investigated the role of inositol triphosphate (Ins P3) isomer formation in this signal transduction pathway. Primary cultures of rat type II pneumocytes were labeled with 30 microCi [3H]myoinositol/5 x 10(6) cells for 48 h. After preincubation with 10 mM LiCl for 20 min, the cells were stimulated with ATP (10(-4) M) and then were rapidly frozen with liquid N2. The Ins P3 isomers were analyzed by high performance liquid chromatography. A 4-fold increase in Ins 1,4,5 P3 occurred within 2 s after stimulation with ATP, decreased to half maximum by 60 s, and returned close to baseline values by 2 min. In contrast, Ins 1,3,4 P3 did not increase until 15 s, peaked by 60 s with a 4-fold increase, and returned to baseline values by 2 min. Intracellular calcium [( Ca2+]i), measured as Indo-1 fluorescence, also increased 3-fold within 2 s of exposure to ATP (10(-4)M) and fell to a plateau level 25% above baseline values by 10 s. We conclude that Ins 1,4,5 P3 formation and [Ca2+]i release both occur rapidly after exposure of type II pneumocytes to extracellular ATP. We speculate that these early events in type II pneumocyte signal transduction play a role in the initiation of stimulation of surfactant secretion by extracellular ATP.

Epidemiology of PPNG infections in Amsterdam: analysis by auxanographic typing and plasmid characterisation

In January 1981 the incidence of penicillinase producing Neisseria gonorrhoeae (PPNG) strains in Amsterdam had increased to 18% of all new cases of gonorrhoea. Auxanographic typing in combination with plasmid determination of 729 PPNG strains showed that in 1981 the predominant and endemic types were those with the Africa plasmid and transfer factor which were non-requiring and inhibited by phenylalanine. In 1982 proline requiring strains with the Asia plasmid and transfer factor increased after being imported and spread by prostitution. Four different plasmid patterns and 12 auxotypes were distinguishable. Unusual auxotypes of both African and Asian plasmid types are frequently imported, some disappearing soon after their introduction into Holland but others providing an opportunity to trace sources and contacts. Prostitution and the biological properties of PPNG strains seem to play an important role in their spread. Only 2.6% of them were isolated from homosexual men. In areas where PPNG strains are prevalent, auxotyping is an important tool in their surveillance.

Single 1 g dose of cefotaxime in the treatment of infections due to penicillinase-producing strains of Neisseria gonorrhoeae

One hundred and two patients with an uncomplicated infection due to penicillinase-producing strains of Neisseria gonorrhoeae (PPNG) were treated with a single 1 g dose of cefotaxime. At follow-up within 15 days all genital and rectal infections were cured. Pharyngeal infections also seemed to respond to this treatment. A relatively high proportion (30.9%) of patients, however, developed post-gonococcal urethritis.

Prevalence of syphilis and hepatitis B among homosexual men in two saunas in Amsterdam

In a pilot study by field-screening in two different sauna baths, a day-sauna and a night-sauna, 318 homosexual men were investigated for syphilis and hepatitis B surface antigen (HBsAg) and its antibody (anti-HBs). Of the 134 visitors to the day-sauna 35.1% were seroreactive for syphilis, four (3%) carried HBsAg, and 95 (70.9%) anti-HBs. Of the 184 visitors to the night-sauna 33.2% were seroreactive for syphilis, 16 (8.7%), carried HBsAg, and 97 (52.7%) anti-HBs. The correlation between seroreactivity for syphilis and the presence of HBsAg amd anti-HBs was statistically significant.

A study on the clinical application of a direct leukocyte migration test in chromium contact allergy

A capillary tube leukocyte migration inhibition assay has been adopted as an in vitro method for the demonstration of chromium hypersensitivity in twenty-two subjects with clinically proven or suspected chromium allergy. Two complexes of trivalent chromium and human serum albumin, exerting different migration inhibitory effects, have been prepared and used as the antigen. In the presence of the chromium-albumin complex with strong inhibitory activity, sensitivity to chromium was demonstrated independent of the clinical condition of the skin in all the patch test positive subjects. An additional positive response to the second chromium-albumin complex was observed only in those patients who were clinically in a state of exacerbation of an allergic contact dermatitis in which chromium allergy was an active causative factor. The results were not influenced by skin allergic reactivity to compounds other than chromium and the method was found to be of practical clinical value for diagnosing chromium allergy.