| 1. |
- Grujic, Mirjana, et al.
(författare)
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Protective role of mouse mast cell tryptase Mcpt6 in melanoma.
- 2020
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Ingår i: Pigment Cell & Melanoma Research. - : Wiley. - 1755-1471 .- 1755-148X. ; 33:4, s. 579-590
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Tidskriftsartikel (refereegranskat)abstract
- Tryptase-positive mast cells populate melanomas, but it is not known whether tryptase impacts on melanoma progression. Here we addressed this and show that melanoma growth is significantly higher in tryptase-deficient (Mcpt6-/- ) versus wild-type mice. Histochemical analysis showed that mast cells were frequent in the tumor stroma of both wild-type and Mcpt6-/- mice, and also revealed their presence within the tumor parenchyma. Confocal microscopy analysis revealed that tryptase was taken up by the tumor cells. Further, tryptase-positive granules were released from mast cells and were widely distributed within the tumor tissue, suggesting that tryptase could impact on the tumor microenvironment. Indeed, gene expression analysis showed that the absence of Mcpt6 caused decreased expression of numerous genes, including Cxcl9, Tgtp2, and Gbp10, while the expression of 5p-miR3098 was enhanced. The levels of CXCL9 were lower in serum from Mcpt6-/- versus wild-type mice. In further support of a functional impact of tryptase on melanoma, recombinant tryptase (Mcpt6) was taken up by cultured melanoma cells and caused reduced proliferation. Altogether, our results indicate a protective role of mast cell tryptase in melanoma growth.
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| 2. |
- Sanna, Adriana, et al.
(författare)
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Tumor genetic heterogeneity analysis of chronic sun-damaged melanoma
- 2020
-
Ingår i: Pigment Cell & Melanoma Research. - : Wiley. - 1755-148X .- 1755-1471. ; 33:3, s. 480-489
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Tidskriftsartikel (refereegranskat)abstract
- Chronic sun-damaged (CSD) melanoma represents 10%-20% of cutaneous melanomas and is characterized by infrequent BRAF V600E mutations and high mutational load. However, the order of genetic events or the extent of intra-tumor heterogeneity (ITH) in CSDhigh melanoma is still unknown. Ultra-deep targeted sequencing of 40 cancer-associated genes was performed in 72 in situ or invasive CMM, including 23 CSDhigh cases. In addition, we performed whole exome and RNA sequencing on multiple regions of primary tumor and multiple in-transit metastases from one CSDhigh melanoma patient. We found no significant difference in mutation frequency in melanoma-related genes or in mutational load between in situ and invasive CSDhigh lesions, while this difference was observed in CSDlow lesions. In addition, increased frequency of BRAF V600K, NF1, and TP53 mutations (p < .01, Fisher's exact test) was found in CSDhigh melanomas. Sequencing of multiple specimens from one CSDhigh patient revealed strikingly limited ITH with >95% shared mutations. Our results provide evidence that CSDhigh and CSDlow melanomas are distinct molecular entities that progress via different genetic routes.
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| 3. |
- Schwochow, Doreen, et al.
(författare)
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The feather pattern autosomal barring in chicken is strongly associated with segregation at the MC1R locus
- 2021
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Ingår i: Pigment Cell & Melanoma Research. - : John Wiley & Sons. - 1755-1471 .- 1755-148X. ; 34:6, s. 1015-1028
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Tidskriftsartikel (refereegranskat)abstract
- Color patterns within individual feathers are common in birds but little is known about the genetic mechanisms causing such patterns. Here, we investigate the genetic basis for autosomal barring in chicken, a horizontal striping pattern on individual feathers. Using an informative backcross, we demonstrate that the MC1R locus is strongly associated with this phenotype. A deletion at SOX10, underlying the dark brown phenotype on its own, affects the manifestation of the barring pattern. The coding variant L133Q in MC1R is the most likely causal mutation for autosomal barring in this pedigree. Furthermore, a genetic screen across six different breeds showing different patterning phenotypes revealed that the most striking shared characteristics among these breeds were that they all carried the MC1R alleles Birchen or brown. Our data suggest that the presence of activating MC1R mutations enhancing pigment synthesis is an important mechanism underlying pigmentation patterns on individual feathers in chicken. We propose that MC1R and its antagonist ASIP play a critical role for determining within-feather pigmentation patterns in birds by acting as activator and inhibitor possibly in a Turing reaction-diffusion model.
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| 4. |
- Wäster, Petra, et al.
(författare)
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Extracellular vesicles released by melanocytes after UVA irradiation promote intercellular signaling via miR21
- 2020
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Ingår i: Pigment Cell & Melanoma Research. - : WILEY. - 1755-1471 .- 1755-148X. ; 33:4, s. 542-555
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Tidskriftsartikel (refereegranskat)abstract
- Skin pigmentation is controlled by complex crosstalk between melanocytes and keratinocytes and is primarily induced by exposure to ultraviolet (UV) irradiation. Several aspects of UVA-induced signaling remain to be explored. In skin cells, UVA induces plasma membrane damage, which is repaired by lysosomal exocytosis followed by instant shedding of extracellular vesicles (EVs) from the plasma membrane. The released EVs are taken up by neighboring cells. To elucidate the intercellular crosstalk induced by UVA irradiation, EVs were purified from UVA-exposed melanocytes and added to keratinocytes. Transcriptome analysis of the keratinocytes revealed the activation of TGF-beta and IL-6/STAT3 signaling pathways and subsequent upregulation of microRNA (miR)21. EVs induced phosphorylation of ERK and JNK, reduced protein levels of PDCD4 and PTEN, and augment antiapoptotic signaling. Consequently, keratinocyte proliferation and migration were stimulated and UV-induced apoptosis was significantly reduced. Interestingly, melanoma cells and melanoma spheroids also generate increased amounts of EVs with capacity to stimulate proliferation and migration upon UVA. In conclusion, we present a novel intercellular crosstalk mediated by UVA-induced lysosome-derived EVs leading to the activation of proliferation and antiapoptotic signaling via miR21.
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| 5. |
- Zheng, Guoqiao, et al.
(författare)
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Association between tumor characteristics and second primary cancers with cutaneous melanoma survival : A nationwide cohort study
- 2020
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Ingår i: Pigment Cell and Melanoma Research. - : Wiley. - 1755-1471 .- 1755-148X. ; 33:4, s. 625-632
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Tidskriftsartikel (refereegranskat)abstract
- The increased survival in malignant cutaneous melanoma (melanoma) is probably due to early diagnosis combined with improved treatment most recently. National health campaigns and screening programs for melanoma detection were started in Sweden several decades ago. We want to assess the influence of tumor characteristics, based on the TNM classification, and of second primary cancers on overall survival in melanoma. We used the Swedish Cancer Registry to assess all-cause survival in melanoma from 2003 to 2015. Hazard ratios (HRs) were estimated using multivariable Cox regression models. A total of 19,773 melanoma patients were diagnosed with TNM data. Survival showed a strong improving trend over time (p-trend <.001). T1a was the most common classification (48.0% of all), while higher T class was associated systematically with worse survival (p-trend <.001). For distant metastases, the HR was 3.17, accounting for 0.9% of the patients. Any types of second primary cancers, other than melanoma, were associated with an HR of 2.00, accounted for 6.7% of all cases. Even if melanoma survival in Sweden ranks among the best national rates, the large percentage of patients with advanced tumors (T3b, T4a, and T4b, 17%) and 21% of deaths with T1a call for improved preventive and follow-up strategies.
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| 6. |
- Rydén, Viktoria, et al.
(författare)
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The role of dacarbazine and temozolomide therapy after treatment with immune checkpoint inhibitors in malignant melanoma patients : A case series and meta-analysis
- 2024
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Ingår i: Pigment Cell & Melanoma Research. - : John Wiley & Sons. - 1755-148X. ; 37:3, s. 352-362
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Tidskriftsartikel (refereegranskat)abstract
- Dacarbazine (DTIC) and its oral counterpart temozolomide (TMZ) have been the most used agents in advanced malignant melanoma (MM) patients and they are still used routinely. The preferred first line treatment, immune checkpoint inhibitors (CPIs) might shape the tumor and the tumor microenvironment, possibly affecting the response to subsequent therapies. The aim of this study was to investigate the treatment effect of DTIC/TMZ in MM patients after CPI therapy in a consecutive patient cohort and through systematic literature review and meta-analysis. Thirty-five patients with advanced MM treated with DTIC/TMZ after previous CPI therapy in three Swedish regions between 2017 and 2021 were recognized and seven case series studies were identified through systematic database review. Pooled data from all 345 patients showed a median real-world progression-free survival (rwPFS) of 1.9 months and overall survival (OS) of 6.0 months. Three of these studies were included in a meta-analysis comparing DTIC/TMZ after CPI treatment, versus no previous immunotherapy, showing no statistically significant differences in rwPFS or OS but higher real-world response rate to chemotherapy for the prior-CPI treated group (Odds Ratio: 2.24; 95% Confidence Interval: 1.04-4.86). The current study supports consideration of DTIC/TMZ in later line of treatment in the immunotherapy era.
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| 7. |
- Sanna, Adriana, et al.
(författare)
-
Tumor genetic heterogeneity analysis of chronic sun-damaged melanoma.
- 2020
-
Ingår i: Pigment cell & melanoma research. - : Wiley-Blackwell. - 1755-148X. ; 33:3, s. 480-489
-
Tidskriftsartikel (refereegranskat)abstract
- Chronic sun-damaged (CSD) melanoma represents 10%-20% of cutaneous melanomas and is characterized by infrequent BRAF V600E mutations and high mutational load. However, the order of genetic events or the extent of intra-tumor heterogeneity (ITH) in CSDhigh melanoma is still unknown. Ultra-deep targeted sequencing of 40 cancer-associated genes was performed in 72 in situ or invasive CMM, including 23 CSDhigh cases. In addition, we performed whole exome and RNA sequencing on multiple regions of primary tumor and multiple in-transit metastases from one CSDhigh melanoma patient. We found no significant difference in mutation frequency in melanoma-related genes or in mutational load between in situ and invasive CSDhigh lesions, while this difference was observed in CSDlow lesions. In addition, increased frequency of BRAF V600K, NF1, and TP53 mutations (p < .01, Fisher's exact test) was found in CSDhigh melanomas. Sequencing of multiple specimens from one CSDhigh patient revealed strikingly limited ITH with >95% shared mutations. Our results provide evidence that CSDhigh and CSDlow melanomas are distinct molecular entities that progress via different genetic routes.
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