Melanoma is the most aggressive and life-threatening skin cancer type. The melanoma genome is the most frequently mutated, with the
mutation present in 40-60% of melanoma cases.
-mutated melanomas ...are characterized by a higher aggressiveness and progression. Adjuvant targeted treatments, such as BRAF and MEK inhibitors, are added to surgical excision in
-mutated metastatic melanomas to maximize treatment effectiveness. However, resistance remains the major therapeutic problem. Interest in natural products, like propolis, for therapeutic applications, has increased in the last years. Propolis healing proprieties offer great potential for the development of novel cancer drugs. As the activity of Portuguese propolis has never been studied in melanoma, we evaluated the antitumoral activity of propolis from Gerês (G18.EE) and its fractions (
-hexane, ethyl acetate (EtOAc), and
-butanol) in A375 and WM9 melanoma cell lines. Results from DPPH•/ABTS• radical scavenging assays indicated that the samples had relevant antioxidant activity, however, this was not confirmed in the cell models. G18.EE and its fractions decreased cell viability (SRB assay) and promoted ROS production (DHE/Mitotracker probes by flow cytometry), leading to activation of apoptotic signaling (expression of apoptosis markers). Our results suggest that the
-BuOH fraction has the potential to be explored in the pharmacological therapy of melanoma.
Melanoma is the deadliest type of skin cancer, with about 61,000 deaths annually worldwide. Late diagnosis increases mortality rates due to melanoma's capacity to metastasise rapidly and patients' ...resistance to the available conventional therapies. Consequently, the interest in natural products as a strategy for drug discovery has been emerging. Propolis, a natural product produced by bees, has several biological properties, including anticancer effects. Propolis from Gerês is one of the most studied Portuguese propolis. Our group has previously demonstrated that an ethanol extract of Gerês propolis collected in 2018 (G18.EE) and its fractions (
-hexane, ethyl acetate, and
-butanol) decrease melanoma cell viability. Out of all the fractions, G18.EE-
-BuOH showed the highest potential as a melanoma pharmacological therapy. Thus, in this work, G18.EE-
-BuOH was fractioned into 17 subfractions whose effect was evaluated in A375
-mutated melanoma cells. The subfractions with the highest cytotoxic activity were analysed by UPLC-DAD-ESI/MS
in an attempt to understand which phenolic compounds could account for the anti-melanoma activity. The compounds identified are typical of the Gerês propolis, and some of them have already been linked with antitumor effectiveness. These results reaffirm that propolis compounds can be a source of new drugs and the isolation of compounds could allow its use in traditional medicine.
Introduction. The Cancer Genome Atlas (TCGA) project and Asian Cancer Research Group (ACRG) recently categorized gastric cancer into molecular subtypes. Nevertheless, these classification systems ...require high cost and sophisticated molecular technologies, preventing their widespread use in the clinic. This study is aimed to generating molecular subtypes of gastric cancer using techniques available in routine diagnostic practice in a series of Moroccan gastric cancer patients. In addition, we assessed the associations between molecular subtypes, clinicopathological features, and prognosis. Methods. Ninety-seven gastric cancer cases were classified according to TCGA, ACRG, and integrated classifications using a panel of four molecular markers (EBV, MSI, E-cadherin, and p53). HER2 status and PD-L1 expression were also evaluated. These markers were analyzed using immunohistochemistry (E-cadherin, p53, HER2, and PD-L1), in situ hybridization (EBV and HER2 equivocal cases), and multiplex PCR (MSI). Results. Our results showed that the subtypes presented distinct clinicopathological features and prognosis. EBV-positive gastric cancers were found exclusively in male patients. The GS (TCGA classification), MSS/EMT (ACRG classification), and E-cadherin aberrant subtype (integrated classification) presented the Lauren diffuse histology enrichment and tended to be diagnosed at a younger age. The MSI subtype was associated with a better overall survival across all classifications (TCGA, ACRG, and integrated classification). The worst prognosis was observed in the EBV subtype (TCGA and integrated classification) and MSS/EMT subtype (ACRG classification). Discussion/Conclusion. We reported a reproducible and affordable gastric cancer subtyping algorithms that can reproduce the recently recognized TCGA, ACRG, and integrated gastric cancer classifications, using techniques available in routine diagnosis. These simplified classifications can be employed not only for molecular classification but also in predicting the prognosis of gastric cancer patients.
Purpose
High-grade gliomas (HGG) remain one of the most aggressive tumors, which is primarily due to its diffuse infiltrative nature. Serine proteases and metalloproteases are known to play key roles ...in cellular migration and invasion mechanisms. SPINT2, also known as HAI-2, is an important serine protease inhibitor that can affect MET signaling. SPINT2 has been found to be frequently downregulated in various tumors, whereby hypermethylation of its promoter appears to serve as a common mechanism. Here, we assessed the clinical relevance of SPINT2 expression and promoter hypermethylation in pediatric and adult HGG and explored its functional role.
Methods
A series of 371 adult and 77 pediatric primary HGG samples was assessed for SPINT2 protein expression (immunohistochemistry) and promoter methylation (methylation-specific PCR) patterns. After
SPINT2
knockdown and knock-in in adult and pediatric HGG cell lines, a variety of
in vitro
assays was carried out to determine the role of SPINT2 in glioma cell viability and invasion, as well as their mechanistic associations with metalloprotease activities.
Results
We found that SPINT2 protein expression was frequently absent in adult (85.3%) and pediatric (100%) HGG samples. The
SPINT2
gene promoter was found to be hypermethylated in approximately half of both adult and pediatric gliomas. Through functional assays we revealed a suppressor activity of SPINT2 in glioma cell proliferation and viability, as well as in their migration and invasion. These functions appear to be mediated in part by MMP2 expression and activity.
Conclusions
We conclude that dysregulation of SPINT2 is a common event in both pediatric and adult HGG, in which SPINT2 may act as a tumor suppressor.
Invasion and metastasis are the leading causes of cancer mortality. That is related to the deregulation of proteases involved in the maintenance of the extracellular matrix and activation of ...advantageous signaling pathways in solid tumors. SPINT2 is a serine protease inhibitor identified as a tumor suppressor gene involved in HGF/MET signaling and epithelial to mesenchymal transition mechanism. SPINT2 promoter is hypermethylated in various solid tumors, leading to its downregulation, including in melanoma, the deadliest skin cancer. BRAFinhibitors are used for melanoma treatment, although survivors ultimately develop resistance. Therefore, evaluating the functional role and therapeutic potential of SPINT2 in melanoma are the main objectives of this project.For that, we produced stable transfectants of three melanoma cell lines to modulate SPINT2 expression and assessed cellular viability, migration, proliferation, and spheroids growth using two and three-dimensional cell culture models. Effect of SPINT2 deregulation in some mediators and pathways was evaluated to understand SPINT2 influence. Besides that, SPINT2influence in tumor response to different drugs used in melanoma treatment as well MET inhibitors was evaluated.In vitro analysis showed that SPINT2 expression resulted in a decrease of the cell migration, cell viability, cell proliferation and tumor spheroid growth. Besides that, higher levels of E-cadherin and lower levels of N-cadherinwere observed with SPINT2 presence. Moreover, SPINT2 expression seemed to correlate with a decrease of p-STAT3, pERK and p-p90rsk levels. Results regarding melanoma cell sensitivity to targeted therapies available, demonstrated that SPINT2 expression increased the sensibility to BRAF and MEK inhibitors, in BRAF V600E mutated cell lines and decreased to MET inhibitors.In summary, our results confirmed the functional role of SPINT2 as a tumor suppressor gene in melanoma. Also, a correlation of SPINT2 absence and epithelial to mesenchymal transition markers was seen, as with proteins related to tumor progression. Our results showed that SPINT2 absence in melanoma is related to a more aggressive tumor phenotype and the potential for SPINT2 as a biomarker of melanoma therapy. Moreover, the use of MET inhibitors for melanoma treatment with SPINT2 downregulation can be a way to overcome resistance. Nevertheless, in future studies it will be important to clarify the therapeutic influence of SPINT2 in melanoma cells, investigate the tumorigenic role and therapeutic influence of SPINT2 in vivo,as well as address these questions in studies of cohorts of human melanoma samples.
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