PD-1/PD-L1 Inhibitors Response in Triple-Negative Breast Cancer: Can Long Noncoding RNAs Be Associated?

As immune checkpoint inhibitors (ICI) emerge as a paradigm-shifting treatment option for patients with advanced or metastatic cancer, there is a growing demand for biomarkers that can distinguish which patients are likely to benefit. In the case of triple-negative breast cancer (TNBC), characterized by a lack of therapeutic targets, pembrolizumab approval for high-risk early-stage disease occurred regardless of PD-L1 status, which keeps the condition in a biomarker limbus. In this review, we highlight the participation of long non-coding RNAs (lncRNAs) in the regulation of the PD-1/PD-L1 pathway, as well as in the definition of prognostic immune-related signatures in many types of tumors, aiming to shed light on molecules that deserve further investigation for a potential role as biomarkers. We also conducted a bioinformatic analysis to investigate lncRNAs already investigated in PD-1/PDL-1 pathways in other cancer types, considering the TNBC molecular context. In this sense, from the generated data, we evidence here two lncRNAs, UCA1 and HCP5, which have not yet been identified in the context of the tumoral immune response in breast cancer. These candidates can be further explored to verify their use as biomarkers for ICI response. In this article, we present an updated review regarding the use of lncRNA as biomarkers of response to ICI, highlighting the versatility of using these molecules.

Sertraline as a potential cancer therapeutic approach: Biological relevance of TCTP in breast cancer cell lines and tumors.

PURPOSE: This study aimed to evaluate the role of Translationally Controlled Tumor Protein (TCTP) in breast cancer (BC) and investigate the effects of sertraline, a serotonin selective reuptake inhibitor (SSRI), on BC cells. The objective was to assess the potential of sertraline as a therapeutic agent in BC treatment by examining its ability to inhibit TCTP expression and exert antitumor effects. MATERIAL AND METHODS: We utilized five different BC cell lines representing the molecular heterogeneity and distinct subtypes of BC, including luminal, normal-like, HER2-positive, and triple-negative BC. These subtypes play a crucial role in determining clinical treatment strategies and prognosis. RESULTS: The highest levels of TCTP were observed in triple-negative BC cell lines, known for their aggressive behavior. Sertraline treatment reduced TCTP expression in BC cell lines, significantly impacting cell viability, clonogenicity, and migration. Additionally, sertraline sensitized triple-negative BC cell lines to cytotoxic chemotherapeutic drugs (doxorubicin and cisplatin) suggesting its potential as an adjunctive therapy to enhance the chemotherapeutic response. Bioinformatic analysis of TCTP mRNA levels in TCGA BC data revealed a negative correlation between TCTP levels and patient survival, as well as between TCTP/tpt1 and Ki67. These findings contradict our data and previous studies indicating a correlation between TCTP protein levels and aggressiveness and poor prognosis in BC. CONCLUSIONS: Sertraline shows a promise as a potential therapeutic option for BC, particularly in triple-negative BC. Its ability to inhibit TCTP expression, enhance chemotherapeutic response, highlights its potential clinical utility in BC treatment, specifically in triple-negative BC subtype.

Dysregulation of Transcription Factor Networks Unveils Different Pathways in Human Papillomavirus 16-Positive Squamous Cell Carcinoma and Adenocarcinoma of the Uterine Cervix.

Squamous cell carcinoma (SCC) and adenocarcinoma (ADC) are the most common histological types of cervical cancer (CC). The worse prognosis of ADC cases highlights the need for better molecular characterization regarding differences between these CC types. RNA-Seq analysis of seven SCC and three ADC human papillomavirus 16-positive samples and the comparison with public data from non-tumoral human papillomavirus-negative cervical tissue samples revealed pathways exclusive to each histological type, such as the epithelial maintenance in SCC and the maturity-onset diabetes of the young (MODY) pathway in ADC. The transcriptional regulatory network analysis of cervical SCC samples unveiled a set of six transcription factor (TF) genes with the potential to positively regulate long non-coding RNA genes DSG1-AS1, CALML3-AS1, IGFL2-AS1, and TINCR. Additional analysis revealed a set of MODY TFs regulated in the sequence predicted to be repressed by miR-96-5p or miR-28-3p in ADC. These microRNAs were previously described to target LINC02381, which was predicted to be positively regulated by two MODY TFs upregulated in cervical ADC. Therefore, we hypothesize LINC02381 might act by decreasing the levels of miR-96-5p and miR-28-3p, promoting the MODY activation in cervical ADC. The novel TF networks here described should be explored for the development of more efficient diagnostic tools.

Environmental prospecting of black yeast-like agents of human disease using culture-independent methodology.

Melanized fungi and black yeasts in the family Herpotrichiellaceae (order Chaetothyriales) are important agents of human and animal infectious diseases such as chromoblastomycosis and phaeohyphomycosis. The oligotrophic nature of these fungi enables them to survive in adverse environments where common saprobes are absent. Due to their slow growth, they lose competition with common saprobes, and therefore isolation studies yielded low frequencies of clinically relevant species in environmental habitats from which humans are thought to be infected. This problem can be solved with metagenomic techniques which allow recognition of microorganisms independent from culture. The present study aimed to identify species of the family Herpotrichiellaceae that are known to occur in Brazil by the use of molecular markers to screen public environmental metagenomic datasets from Brazil available in the Sequence Read Archive (SRA). Species characterization was performed with the BLAST comparison of previously described barcodes and padlock probe sequences. A total of 18,329 sequences was collected comprising the genera Cladophialophora, Exophiala, Fonsecaea, Rhinocladiella and Veronaea, with a focus on species related to the chromoblastomycosis. The data obtained in this study demonstrated presence of these opportunists in the investigated datasets. The used techniques contribute to our understanding of environmental occurrence and epidemiology of black fungi.

DNA methylation in adolescents with anxiety disorder: a longitudinal study.

Anxiety disorders (AD) typically manifest in children and adolescents and might persist into adulthood. However, there are still few data concerning epigenetic mechanisms associated with onset, persistence or remission of AD over time. We investigated a cohort of adolescents and young adults at baseline (age; 13.19 ± 2.38) and after 5 years and classified them according to the AD diagnosis and their longitudinal trajectories into 4 groups: (1) Typically Developing Comparisons (TDC; control group, n = 14); (2) Incident (AD in the second evaluation only, n = 11); (3) Persistent (AD in both evaluations, n = 14) and (4) Remittent (AD in the first evaluation only, n = 8). DNA methylation was evaluated with the Infinium HumanMethylation450 BeadChip from saliva samples collected at both evaluations. Gene set enrichment analysis was applied to consider biological pathways. We found decreased DNA methylation in TDC group while the chronic cases of AD presented hypermethylation in central nervous system development pathways. Moreover, we showed that this persistent group also presented hypermethylation while the other three groups were associated with hypomethylation in nervous system development pathway. Incidence and remission groups were associated with increased and decreased methylation in neuron development pathways, respectively. Larger studies are likely to detect specific genes relevant to AD.

Protein Function Prediction.

Protein function is a concept that can have different interpretations in different biological contexts, and the number and diversity of novel proteins identified by large-scale "omics" technologies poses increasingly new challenges. In this review we explore current strategies used to predict protein function focused on high-throughput sequence analysis, as for example, inference based on sequence similarity, sequence composition, structure, and protein-protein interaction. Various prediction strategies are discussed together with illustrative workflows highlighting the use of some benchmark tools and knowledge bases in the field.

In vitro evaluation of antitumoral efficacy of catalase in combination with traditional chemotherapeutic drugs against human lung adenocarcinoma cells.

Lung cancer is the most lethal cancer-related disease worldwide. Since survival rates remain poor, there is an urgent need for more effective therapies that could increase the overall survival of lung cancer patients. Lung tumors exhibit increased levels of oxidative markers with altered levels of antioxidant defenses, and previous studies demonstrated that the overexpression of the antioxidant enzyme catalase (CAT) might control tumor proliferation and aggressiveness. Herein, we evaluated the effect of CAT treatment on the sensitivity of A549 human lung adenocarcinoma cells toward various anticancer treatments, aiming to establish the best drug combination for further therapeutic management of this disease. Exponentially growing A549 cells were treated with CAT alone or in combination with chemotherapeutic drugs (cisplatin, 5-fluorouracil, paclitaxel, daunorubicin, and hydroxyurea). CalcuSyn(®) software was used to assess CAT/drug interactions (synergism or antagonism). Growth inhibition, NFκB activation status, and redox parameters were also evaluated in CAT-treated A549 cells. CAT treatment caused a cytostatic effect, decreased NFκB activation, and modulated the redox parameters evaluated. CAT treatment exhibited a synergistic effect among most of the anticancer drugs tested, which is significantly correlated with an increased H2O2 production. Moreover, CAT combination caused an antagonism in paclitaxel anticancer effect. These data suggest that combining CAT (or CAT analogs) with traditional chemotherapeutic drugs, especially cisplatin, is a promising therapeutic strategy for the treatment of lung cancer.

miRNA-21 and miRNA-34a Are Potential Minimally Invasive Biomarkers for the Diagnosis of Pancreatic Ductal Adenocarcinoma.

OBJECTIVES: Pancreatic ductal adenocarcinoma (PDAC) is one of the most deadly cancers, and its diagnosis often requires invasive procedures. Deregulated miRNA expression has been described in patients with PDAC. In this study, we analyzed the expression levels of 6 miRNAs (miR-21, -34a, -155, -196a, -200b, and -376a involved in PDAC tumorigenesis) in serum and salivary samples to assess their potential role as circulating diagnostics biomarkers. METHODS: Serum and salivary samples were collected from patients with PDAC and healthy controls, and miRNA levels were quantified using qRT-PCR. Twenty-four patients with PDAC and 10 healthy controls were recruited. RESULTS: A significant difference between PDAC and healthy groups was observed for the expression of miR-21 and miR-34a (P < 0.001 and P = 0.001) in serum samples. Both miRNAs accurately discriminated between the 2 groups, with an area under the curve for miR-21 and miR-34a of 0.889 (P = 0.001) and 0.865 (P = 0.002), respectively. In general, the expression of miRNAs between salivary samples did not differ. CONCLUSIONS: Serum miR-21 and miR-34a are potentially useful diagnostic biomarkers of PDAC. In addition, our results suggest that these miRNAs are not differentially expressed in saliva, making them unsuitable for use as noninvasive biomarkers for diagnostic purposes.

Potential crosstalk between cofilin-1 and EGFR pathways in cisplatin resistance of non-small-cell lung cancer.

Current challenge in oncology is to establish the concept of personalized medicine in clinical practice. In this context, non-small-cell lung cancer (NSCLC) presents clinical, histological and molecular heterogeneity, being one of the most genomically diverse of all cancers. Recent advances added Epidermal Growth Factor Receptor (EGFR) as a predictive biomarker for patients with advanced NSCLC. In tumors with activating EGFR mutations, tyrosine kinase inhibitors (TKI) are indicated as first-line treatment, although restricted to a very small target population. In this context, cofilin-1 (a cytosolic protein involved with actin dynamics) has been widely studied as a biomarker of an aggressive phenotype in tumors, and overexpression of cofilin-1 is associated with cisplatin resistance and poor prognosis in NSCLC. Here, we gather information about the predictive potential of cofilin-1 and reviewed the crosstalk between cofilin-1/EGFR pathways. We aimed to highlight new perspectives of how these interactions might affect cisplatin resistance in NSCLC. We propose that cofilin-1 quantification in clinical samples in combination with presence/absence of EGFR mutation could be used to select patients that would benefit from TKI's treatment. This information is of paramount importance and could result in a possibility of guiding more effective treatments to NSCLC patients.

Induced genome maintenance pathways in pre-cancer tissues describe an anti-cancer barrier in tumor development.

A recent model proposing that a barrier is raised against tumor evolution in pre-cancer tissues is investigated. For that we quantify expression alterations in genome maintenance pathways: DNA damage response, death pathways and cell cycle and also differentially expressed genes in transcriptomes of pre-cancerous and cancerous lesions deposited in the GEO database. We find that the main alterations in pre-cancer samples comprising the barrier are: (1) DNA double strand-breaks signaling and repair pathways induction, (2) upregulation of cyclin-dependent kinases, (3) p53 dependent (and independent) repair and apoptosis pathways induction and (4) replicative senescence induction early in tissue transformation. In the cancer samples we find that the induced pathways in pre-cancer are systematically inhibited and the only remaining induced pathway is p53, whereas the retinoblastoma pathway arises induced in most samples. The results give support to the model, furthermore they reveal the involvement of additional mechanisms in pre-cancer, including the early induction of replicative senescence and of p53 independent apoptosis.

Transcriptomic analysis reveals pH-responsive antioxidant gene networks.

Reactive oxygen species (ROS) are produced in different physiological conditions. In response to ROS imbalance cells activate oxidative stress defenses, which include more than 60 antioxidant genes. It has been suggested that gene products associated with ROS detoxification can work coordinately, acting as an antioxidant-defense network. However, the functional overlap among oxidative stress defenses and other related cell functions makes difficult the characterization of this network. We previously described a network-based model to characterize the interactions existing among different antioxidant gene products and their substrates. Here, we test whether this network-based model of human antioxidant genes can respond to different physiological conditions. We used a systems biology approach applied to the analysis of two independent gene expression datasets: transcriptomes from HeLa cells and primary astrocytes maintained under hypoxic conditions and transcriptomes from SKGT4 cells exposed to low pH environment. We found that the proposed gene network model responds selectively to both hypoxia and acidosis. We anticipate that this antioxidant gene network model can be helpful to describe stress-responsive expression profiles in different cell types.

Retinol induces morphological alterations and proliferative focus formation through free radical-mediated activation of multiple signaling pathways.

AIM: Toxicity of retinol (vitamin A) has been previously associated with apoptosis and/or cell malignant transformation. Thus, we investigated the pathways involved in the induction of proliferation, deformation and proliferative focus formation by retinol in cultured Sertoli cells of rats. METHODS: Sertoli cells were isolated from immature rats and cultured. The cells were subjected to a 24-h treatment with different concentrations of retinol. Parameters of oxidative stress and cytotoxicity were analyzed. The effects of the p38 inhibitor SB203580 (10 µmol/L), the JNK inhibitor SP600125 (10 µmol/L), the Akt inhibitor LY294002 (10 µmol/L), the ERK inhibitor U0126 (10 µmol/L) the pan-PKC inhibitor Gö6983 (10 µmol/L) and the PKA inhibitor H89 (1 µmol/L) on morphological and proliferative/transformation-associated modifications were studied. RESULTS: Retinol (7 and 14 µmol/L) significantly increases the reactive species production in Sertoli cells. Inhibition of p38, JNK, ERK1/2, Akt, and PKA suppressed retinol-induced [(3)H]dT incorporation into the cells, while PKC inhibition had no effect. ERK1/2 and p38 inhibition also blocked retinol-induced proliferative focus formation in the cells, while Akt and JNK inhibition partially decreased focus formation. ERK1/2 and p38 inhibition hindered transformation-associated deformation in retinol-treated cells, while other treatments had no effect. CONCLUSION: Our results suggest that activation of multiple kinases is responsible for morphological and proliferative changes associated to malignancy development in Sertoli cells by retinol at the concentrations higher than physiological level.

CFL1 expression levels as a prognostic and drug resistance marker in nonsmall cell lung cancer.

BACKGROUND: Nonsmall cell lung cancer (NSCLC) is the major determinant of overall cancer mortality worldwide. Despite progress in molecular research, current treatments offer limited benefits. Because NSCLC generates early metastasis, and this behavior requires great cell motility, herein the authors assessed the potential value of CFL1 gene (main member of the invasion/metastasis pathway) as a prognostic and predictive NSCLC biomarker. METHODS: Metadata analysis of tumor tissue microarray was applied to examine expression of CFL1 in archival lung cancer samples from 111 patients, and its clinicopathologic significance was investigated. The robustness of the finding was validated using another independent data set. Finally, the authors assayed in vitro the role of CFL1 levels in tumor invasiveness and drug resistance using 6 human NSCLC cell lines with different basal degrees of CFL1 gene expression. RESULTS: CFL1 levels in biopsies discriminate between good and bad prognosis at early tumor stages (IA, IB, and IIA/B), where high CFL1 levels are correlated with lower overall survival rate (P<.0001). Biomarker performance was further analyzed by immunohistochemistry, hazard ratio (P<.001), and receiver-operating characteristic curve (area=0.787; P<.001). High CFL1 mRNA levels and protein content are positively correlated with cellular invasiveness (determined by Matrigel Invasion Chamber System) and resistance (2-fold increase in drug 50% growth inhibition dose) against a list of 22 alkylating agents. Hierarchical clustering analysis of the CFL1 gene network had the same robustness for stratified NSCLC patients. CONCLUSIONS: This study indicates that the CFL1 gene and its functional gene network can be used as prognostic biomarkers for NSCLC and could also guide chemotherapeutic interventions.

Inhibition of MDR1 expression by retinol treatment increases sensitivity to etoposide (VP16) in human neoplasic cell line.

Multidrug resistance (MDR) is the major obstacle to cancer chemotherapy. MDR phenotype is mainly related to the over-expression of MDR1 gene, being responsible for tumor resistance to several chemotherapeutic drugs. It has been suggested that MDR1 expression is redox-regulated and we have recently described a pro-oxidative effect of retinol. Here we tested the therapeutic use of retinol as a modulator of MDR1 gene expression in tumor cell lines, and verified in situ the enhancement of anticancer drug efficacy. Two human colorectal adenocarcinoma cell lines (HT29, SW620) with different degrees of MDR1 expression were used. Cells were pre-treated with a sublethal dose of retinol and then challenged with the etoposide (VP16) drug. The drug GI50 was assessed by SRB method and levels of MDR1 expression were determined by semi-quantitative rtPCR. Retinol treatment caused a 40% decrease in MDR1 expression and increased VP16 toxicity. MDR1 expression and drug sensitivity were restored to control values when mannitol (a hydroxyl radical scavenger) was co-administrated. Our data point a role to the use of retinol as an adjuvant in the treatment of tumors with MDR phenotype.