Vemurafenib and dabrafenib are BRAF kinase inhibitors (BRAFi) used for the treatment of patients with melanoma carrying the V600E BRAF mutation. However, melanoma cells develop resistance to both ...drugs when used as monotherapy. Therefore, mechanisms of drug resistance are investigated, and new molecular targets are sought that could completely inhibit melanoma progression. Since receptor-interacting protein kinase (RIPK4) probably functions as an oncogene in melanoma and its structure is similar to the BRAF protein, we analyzed the impact of vemurafenib and dabrafenib on RIPK4 in melanomas. The in silico study confirmed the high similarity of BRAF kinase domains to the RIPK4 protein at both the sequence and structural levels and suggests that BRAFi could directly bind to RIPK4 even more strongly than to ATP. Furthermore, BRAFi inhibited ERK1/2 activity and lowered RIPK4 protein levels in BRAF-mutated melanoma cells (A375 and WM266.4), while in wild-type BRAF cells (BLM and LoVo), both inhibitors decreased the level of RIPK4 and enhanced ERK1/2 activity. The phosphorylation of phosphatidylethanolamine binding protein 1 (PEBP1)-a suppressor of the BRAF/MEK/ERK pathway-via RIPK4 observed in pancreatic cancer did not occur in melanoma. Neither downregulation nor upregulation of RIPK4 in BRAF- mutated cells affected PEBP1 levels or the BRAF/MEK/ERK pathway. The downregulation of RIPK4 inhibited cell proliferation and the FAK/AKT pathway, and increased BRAFi efficiency in WM266.4 cells. However, the silencing of RIPK4 did not induce apoptosis or necroptosis. Our study suggests that RIPK4 may be an off-target for BRAF inhibitors.
Melanoma is a highly aggressive skin cancer, which, although highly immunogenic, frequently escapes the body’s immune defences. Immune checkpoint inhibitors (ICI), such as anti-PD1, anti-PDL1, and ...anti-CTLA4 antibodies lead to reactivation of immune pathways, promoting rejection of melanoma. However, the benefits of ICI therapy remain limited to a relatively small proportion of patients who do not exhibit ICI resistance. Moreover, the precise mechanisms underlying innate and acquired ICI resistance remain unclear. Here, we have investigated differences in melanoma tissues in responder and non-responder patients to anti-PD1 therapy in terms of tumour and immune cell gene-associated signatures. We performed multi-omics investigations on melanoma tumour tissues, which were collected from patients before starting treatment with anti-PD1 immune checkpoint inhibitors. Patients were subsequently categorized into responders and non-responders to anti-PD1 therapy based on RECIST criteria. Multi-omics analyses included RNA-Seq and NanoString analysis. From RNA-Seq data we carried out HLA phenotyping as well as gene enrichment analysis, pathway enrichment analysis and immune cell deconvolution studies. Consistent with previous studies, our data showed that responders to anti-PD1 therapy had higher immune scores (median immune score for responders = 0.1335, median immune score for non-responders = 0.05426, p-value = 0.01, Mann-Whitney U two-tailed exact test) compared to the non-responders. Responder melanomas were more highly enriched with a combination of CD8+ T cells, dendritic cells (p-value = 0.03) and an M1 subtype of macrophages (p-value = 0.001). In addition, melanomas from responder patients exhibited a more differentiated gene expression pattern, with high proliferative- and low invasive-associated gene expression signatures, whereas tumours from non-responders exhibited high invasive- and frequently neural crest-like cell type gene expression signatures. Our findings suggest that non-responder melanomas to anti-PD1 therapy exhibit a de-differentiated gene expression signature, associated with poorer immune cell infiltration, which establishes a gene expression pattern characteristic of innate resistance to anti-PD1 therapy. Improved understanding of tumour-intrinsic gene expression patterns associated with response to anti-PD1 therapy will help to identify predictive biomarkers of ICI response and may help to identify new targets for anticancer treatment, especially with a capacity to function as adjuvants to improve ICI outcomes.
Abstract
Background
Some studies suggest that Human Papilloma Virus (HPV) infection is important factor in carcinogenesis of breast tumors. This study’ objective was to analyze HPV prevalence in ...breast cancers of patients from south-central Poland.
Materials and methods
The study was performed based on archival paraffin embebbed and formalin fixed blocks in the group of 383 patients with breast cancer. HPV prevalence and its genotype were assessed, respectively by: nested PCR (with two groups of primers: PGMY09/PGMY11 and GP5+/GP6+), quantitative PCR (qPCR). Tumors were classified as HPV positive in case of at least one positive result in nested PCR and positive results in genotyping procedure. For all HPV positive tissues P16 immunostaining was applied in order to confirm active viral infection.
Results
In the group of 383 breast cancers, HPV positivity was found in 17 samples (4.4%) in nested PCR. All these samples were subjected to HPV genotyping. This analysis revealed presence of HPV type 16 into two tumors (0.5%). In these two cancers, P16 overexpression was reported.
Conclusion
In breast tumors of patients from south-central Poland in Poland, HPV positivity is demonstrated in very low percentage of cases.
Objectives
In healthy people, the vibrotactile perception threshold (VPT) at fingertips depends on a given measurement method and on individual characteristics such as age, gender and finger skin ...temperature. The aim of the study was to compare the VPT values in 2 groups of healthy subjects with different finger skin temperature.
Materials and Methods
The study group comprised 56 males and 76 females, who formed pairs matched with respect to age, gender and body mass index (BMI) but differing in terms of finger skin temperature at pre-launch testing. The finger skin temperature of less than 29°C indicated the subjects with “cold hands” and that of more than 29°C, the subjects with “warm hands”. The measuring system made use of P8 pallesthesiometer (EMSON-MAT, Poland) and the measurement procedure was in compliance with the ISO 13091-1:2001 standard. VPT measurements were performed for the index, middle and ring fingers of both hands at the frequencies of 4 Hz, 25 Hz, 31.5 Hz, 63 Hz, 125 Hz and 250 Hz.
Results
The findings of the study revealed that the mean VPTs among the subjects with “cold hands” were significantly higher than the corresponding values among the subjects with “warm hands”.
Conclusions
The type of individual peripheral thermoregulation should be considered when assessing the VPT and determining its reference values.
Melanoma comprises <5% of cutaneous malignancies, yet it causes a significant proportion of skin cancer-related deaths worldwide. While new therapies for melanoma have been developed, not all ...patients respond well. Thus, further research is required to better predict patient outcomes. Using long-range nanopore sequencing, RT-qPCR, and RNA sequencing analyses, we examined the transcription of
splice isoforms in melanoma cell lines and patient tissue samples. Seventy-six
mRNA variants were identified in total, with several previously characterised isoforms (γ, φ, δ, ε, and η) contributing to a large proportion of the expressed transcripts. In addition, we identified four novel splice events, namely, Δ(E3_E9), ▼(i8), IVS10+131▼46, and IVS10▼176, occurring in various combinations in multiple transcripts. We found that short-read RNA-Seq analyses were limited in their ability to predict isoforms containing multiple non-contiguous splicing events, as compared to long-range nanopore sequencing. These studies suggest that further investigations into the functional significance of the identified
splice variants in melanoma are warranted.
Contrast-enhanced spectral mammography (CESM) is one of the new diagnostic modalities implemented in clinical practice. In the case of these techniques, there are two major issues to be addressed: ...(1) their diagnostic usefulness, and (2) the relation between parameters assessed using these techniques and well-known diagnostic/prognostic/predictive markers (histological, clinical, and molecular). Therefore, we studied the relationship between the tumour margin assessed on CESM and (1) tumour borders defined on the basis of macroscopic and microscopic examination, (2) pT, (3) pN, and (4) tumour grade in a group of 82 breast cancer patients. Based on CESM, the tumour border was defined as sharp, indistinct or spiculated, whereas in the case of lesions showing weak or medium enhancement on CESM the borders were classified as unspecified. We found a statistically significant relationship between tumour margin on CESM and (1) macroscopic border (a spiculated margin on CESM was found only in carcinomas with an invasive border on histological examination; p = 0.004), (2) pT (p = 0.016), and (3) pN (nodal involvement was observed most frequently in carcinomas with a spiculated or indistinct margin on CESM; p = 0.045). Moreover, in cases with an undefined margin on CESM (cases showing weak or medium enhancement on CESM), both invasive and pushing borders were found on histological examination. The results of our preliminary study suggest that it is possible to assess macroscopic borders of examined lesions on the basis of CESM imaging. This might be useful in planning the extent of surgical excision. On the other hand, the assessment of the tumour margin on CESM might not be precise in cases showing weak enhancement.
Synovial sarcoma is a relatively common soft tissue tumor characterized by highly specific t(X;18)(p11;q11) translocation resulting in the fusion of SS18 with members of SSX gene family. Typically, ...detection of SS18 locus rearrangement by fluorescence in situ hybridization or SS18 :: SSX fusion transcripts confirms the diagnosis. More recently, immunohistochemistry (IHC) for SS18-SSX chimeric protein (E9X9V) and C-terminus of SSX (E5A2C) showed high specificity and sensitivity for synovial sarcoma. This study screened a cohort of >1000 soft tissue and melanocytic tumors using IHC and E9X9V and E5A2C antibodies. Three percent (6/212) of synovial sarcomas were either negative for SS18-SSX or had scattered positive tumor cells (n=1). In these cases, targeted RNA next-generation sequencing detected variants of SS18 :: SSX chimeric transcripts. DNA methylation profiles of 2 such tumors matched with synovial sarcoma. A few nonsynovial sarcoma tumors (n=6) revealed either focal SS18-SSX positivity (n=1) or scattered positive tumor cells. However, targeted RNA next-generation sequencing failed to detect SS18 :: SSX transcripts in these cases. The nature of this immunopositivity remains elusive and may require single cell sequencing studies. All synovial sarcomas showed positive SSX IHC. However, a mosaic staining pattern or focal loss of expression was noticed in a few cases. Strong and diffuse SSX immunoreactivity was also seen in epithelioid sclerosing osteosarcoma harboring EWSR1 :: SSX1 fusion, while several sarcomas and melanocytic tumors including cellular blue nevus (5/7, 71%) revealed focal to diffuse, mostly weak to intermediate SSX staining. The SS18-SSX and SSX IHC is a useful tool for synovial sarcoma differential diagnosis, but unusual immunophenotype should trigger molecular genetic testing.
We report a case of 40-year-old Caucasian man presented with an asymptomatic nodule localized on his arm. The puzzle histiocytosis composed of juvenile xanthogranuloma and Langerhans cell ...histiocytosis was diagnosed. The results of immunohistochemical studies confirm the dual character of histological texture of the lesion.
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