Somatic Copy Number Alterations in Colorectal Cancer Lead to a Differentially Expressed ceRNA Network (ceRNet).

Colorectal cancer (CRC) represents the second deadliest malignancy worldwide. Around 75% of CRC patients exhibit high levels of chromosome instability that result in the accumulation of somatic copy number alterations. These alterations are associated with the amplification of oncogenes and deletion of tumor-ppressor genes and contribute to the tumoral phenotype in different malignancies. Even though this relationship is well known, much remains to be investigated regarding the effect of said alterations in long non-coding RNAs (lncRNAs) and, in turn, the impact these alterations have on the tumor phenotype. The present study aimed to evaluate the role of differentially expressed lncRNAs coded in regions with copy number alterations in colorectal cancer patient samples. We downloaded RNA-seq files of the Colorectal Adenocarcinoma Project from the The Cancer Genome Atlas (TCGA) repository (285 sequenced tumor tissues and 41 non-tumor tissues), evaluated differential expression, and mapped them over genome sequencing data with regions presenting copy number alterations. We obtained 78 differentially expressed (LFC > 1|< -1, padj < 0.05) lncRNAs, 410 miRNAs, and 5028 mRNAs and constructed a competing endogenous RNA (ceRNA) network, predicting significant lncRNA-miRNA-mRNA interactions. Said network consisted of 30 lncRNAs, 19 miRNAs, and 77 mRNAs. To understand the role that our ceRNA network played, we performed KEGG and GO analysis and found several oncogenic and anti-oncogenic processes enriched by the molecular players in our network. Finally, to evaluate the clinical relevance of the lncRNA expression, we performed survival analysis and found that C5orf64, HOTAIR, and RRN3P3 correlated with overall patient survival. Our results showed that lncRNAs coded in regions affected by SCNAs form a complex gene regulatory network in CCR.

The Role of Glucocorticoids in Breast Cancer Therapy.

Glucocorticoids (GCs) are anti-inflammatory and immunosuppressive steroid molecules secreted by the adrenal gland and regulated by the hypothalamic-pituitary-adrenal (HPA) axis. GCs present a circadian release pattern under normal conditions; they increase their release under stress conditions. Their mechanism of action can be via the receptor-independent or receptor-dependent pathway. The receptor-dependent pathway translocates to the nucleus, where the ligand-receptor complex binds to specific sequences in the DNA to modulate the transcription of specific genes. The glucocorticoid receptor (GR) and its endogenous ligand cortisol (CORT) in humans, and corticosterone in rodents or its exogenous ligand, dexamethasone (DEX), have been extensively studied in breast cancer. Its clinical utility in oncology has mainly focused on using DEX as an antiemetic to prevent chemotherapy-induced nausea and vomiting. In this review, we compile the results reported in the literature in recent years, highlighting current trends and unresolved controversies in this field. Specifically, in breast cancer, GR is considered a marker of poor prognosis, and a therapeutic target for the triple-negative breast cancer (TNBC) subtype, and efforts are being made to develop better GR antagonists with fewer side effects. It is necessary to know the type of breast cancer to differentiate the treatment for estrogen receptor (ER)-positive, ER-negative, and TNBC, to implement therapies that include the use of GCs.

Negative Regulation of Serine Threonine Kinase 11 (STK11) through miR-100 in Head and Neck Cancer.

BACKGROUND: Serine Threonine Kinase 11 (STK11), also known as LKB1, is a tumor suppressor gene that regulates several biological processes such as apoptosis, energetic metabolism, proliferation, invasion, and migration. During malignant progression, different types of cancer inhibit STK11 function by mutation or epigenetic inactivation. In Head and Neck Cancer, it is unclear what mechanism is involved in decreasing STK11 levels. Thus, the present work aims to determine whether STK11 expression might be regulated through epigenetic or post-translational mechanisms. METHODS: Expression levels and methylation status for STK11 were analyzed in 59 cases of head and neck cancer and 10 healthy tissue counterparts. Afterward, we sought to identify candidate miRNAs exerting post-transcriptional regulation of STK11. Then, we assessed a luciferase gene reporter assay to know if miRNAs directly target STK11 mRNA. The expression levels of the clinical significance of mir-100-3p, -5p, and STK11 in 495 HNC specimens obtained from the TCGA database were further analyzed. Finally, the Kaplan-Meier method was used to estimate the prognostic significance of the miRNAs for Overall Survival, and survival curves were compared through the log-rank test. RESULTS: STK11 was under-expressed, and its promoter region was demethylated or partially methylated. miR-17-5p, miR-106a-5p, miR-100-3p, and miR-100-5p could be negative regulators of STK11. Our experimental data suggested evidence that miR-100-3p and -5p were over-expressed in analyzed tumor patient samples. Luciferase gene reporter assay experiments showed that miR-100-3p targets and down-regulates STK11 mRNA directly. With respect to overall survival, STK11 expression level was significant for predicting clinical outcomes. CONCLUSION: This is, to our knowledge, the first report of miR-100-3p targeting STK11 in HNC. Together, these findings may support the importance of regulation of STK11 through post-transcriptional regulation in HNC and the possible contribution to the carcinogenesis process in this neoplasia.

Identification of miRNA Master Regulators in Breast Cancer.

Breast cancer is the neoplasm with the highest number of deaths in women. Although the molecular mechanisms associated with the development of this tumor have been widely described, metastatic disease has a high mortality rate. In recent years, several studies show that microRNAs or miRNAs regulate complex processes in different biological systems including cancer. In the present work, we describe a group of 61 miRNAs consistently over-expressed in breast cancer (BC) samples that regulate the breast cancer transcriptome. By means of data mining from TCGA, miRNA and mRNA sequencing data corresponding to 1091 BC patients and 110 normal adjacent tissues were downloaded and a miRNA-mRNA network was inferred. Calculations of their oncogenic activity demonstrated that they were involved in the regulation of classical cancer pathways such as cell cycle, PI3K-AKT, DNA repair, and k-Ras signaling. Using univariate and multivariate analysis, we found that five of these miRNAs could be used as biomarkers for the prognosis of overall survival. Furthermore, we confirmed the over-expression of two of them in 56 locally advanced BC samples obtained from the histopathological archive of the National Cancer Institute of Mexico, showing concordance with our previous bioinformatic analysis.

A Higher Frequency Administration of the Nontoxic Cycloartane-Type Triterpene Argentatin A Improved Its Anti-Tumor Activity.

Parthenium argentatum (Gray), commonly known as guayule, has been used to obtain natural rubber since the beginning of the 20th century. Additionally, the so called "resin" is a waste product derived from the industrial process. The cycloartane-type triterpene Argentatin A (AA) is one of the main constituents of the industrial waste resin. In this study we evaluated the AA anticancer activity both in vitro and in vivo in the HCT116 colon cancer cells. The apoptosis promotion of AA was assessed by the annexin V/propidium iodide (PI) assay. The senescence was evaluated for SA-ß-galactosidase, and PCNA was used as a marker of proliferation. Its antitumor activity was evaluated using a xenograft mouse model. The results indicated that AA-induced apoptosis in HCT-116 cells and was positively stained for SA-ß-galactosidase. In the xenografted mice test, the administration of AA at the dose of 250 mg/kg three times a week for 21 days reduced tumor growth by 78.1%. A comparable tumor reduction was achieved with cisplatin at the dose of 2 mg/kg administered three times a week for 21 days. However, nude mice treated with AA did not lose weight, as they did remarkably when treated with cisplatin. Furthermore, the animals treated with AA showed similar blood profiles as the healthy control group. These data indicate the low toxicity of AA compared to that shown by cisplatin.

The Phytosterol Peniocerol Inhibits Cell Proliferation and Tumor Growth in a Colon Cancer Xenograft Model.

Objective: This study aimed to evaluate the cytotoxic activity of peniocerol against human colon cancer cell lines and its antitumor effect in vivo in a xenograft model using nu/nu mice. Materials and Methods: SW-620, HCT-15, and HCT-116 colon cancer cell lines were treated with peniocerol for cytotoxicity by crystal violet technique. Cell apoptosis induction was detected by flow cytometry, and the antitumor activity of peniocerol was evaluated in a xenograft model of HCT-116 in nu/nu mice. After treatment, the effect of peniocerol was analyzed in histological sections of tumors by immunohistochemistry using DAPI, anti-PCNA, and PARP-1 antibodies. Results: Peniocerol inhibited cell growth and induced apoptosis in vitro in a time and dose-dependent manner. Besides, peniocerol administration (30 or 15 mg/kg) inhibited tumor growth and induced apoptosis in the xenograft mice. The lack of peniocerol toxicity was proved by a biochemical blood analysis of healthy nu/nu mice administrated with this sterol. Conclusions: Our results proved that peniocerol induces apoptosis in vitro and in vivo assays.

Masticadienonic and 3α-OH Masticadienoic Acids Induce Apoptosis and Inhibit Cell Proliferation and Tumor Growth in Prostate Cancer Xenografts in Vivo.

The triterpenes have been constituted as a group of interesting molecules as possible antitumor agents. Despite several of them not presenting a potent cytotoxic activity in vitro against cancer cells, in vivo in xenotransplant tumors studies, they show promising results. Based on the above considerations, we investigated the antitumor activity of both masticadienonic (MDA) and 3α-OH masticadienoic (3α-OH MDA) acids in a mouse prostate cancer xenograft model. Immunohistochemical assays were used to evaluate the decrease in the expression of the Proliferating Cell Nuclear Antigen (PCNA) and the Ki-67 induced by MDA and 3α-OH MDA. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay was performed to demonstrate the fragmentation of DNA. Our results showed that the two triterpenes inhibited tumor growth, had anti-proliferative effect in vivo and induced cell death by apoptosis. Collectively, our data suggested that the antitumor mechanism of MDA and 3α-OH MDA involves several molecular targets related to cell proliferation and apoptosis.

Targeting Metabolic Remodeling in Triple Negative Breast Cancer in a Murine Model.

Background: Chemotherapy is the backbone of systemic treatment for triple negative breast cancer (TNBC), which is one of the most relevant breast cancers molecular types due to the ability of tumor cells to develop drug resistance, highlighting the urgent need to design newer and safer drug combinations for treatment. In this context, to overcome tumor cell drug resistance, we employed a novel combinatorial treatment including Doxorubicin, Metformin, and Sodium Oxamate (DoxMetOx). Such pharmacological combination targets indispensable hallmarks of cancer-related to aerobic glycolysis and DNA synthesis. Materials and Methods: Thirty-five female nude mice were transplanted subcutaneously with MDA-MB-231 triple negative human cancer cell line. Once tumors were visible, mice were treated with doxorubicin, metformin, oxamate or all possible pharmacologic combinations. Treatments were administered daily for 15 days and tumors were measured by calipers every day. MicroPET images were taken in three different occasions, basal state, in the middle of the treatment, and at the end of treatment. Western blot analyses, qRT-PCR, flow cytometry, and cytotoxicity assays were performed to elucidate the mechanism of cell death promoted by the drugs in vitro. Results: In this work we assessed the proof of concept of metabolic correction in solid tumors as an effective drug treatment; hence, mice bearing tumors treated with the DoxMetOx therapy showed a complete inhibition of the tumor mass growing in 15 days of treatment depicted by the micro PET images. In vitro studies displayed that the three drugs together act by inhibiting both, mTOR-phosphorylation and expression of LDH-A gene, promoting apoptosis via dependent on the caspase-3 pathway, accompanied by cleavage of PARP. Moreover, induction of autophagy process was observed by the accumulation of LC3-II, a primordial protein implicated in the conformation and elongation of the autophagolysosome. Conclusions: The lack of effective drugs to inhibit TNBC growth is the main cause of therapy failure and tumor relapse. We have showed that targeting crucial molecular pathways in cancer by the combination of Doxorubicin, Metformin, and Oxamate resulted as an efficient and rapid tumor growth inhibitor in a triple negative xenograft model. Our findings are promising for patients diagnosed with TNBC tumors, for which unfortunately there are no reliable drug therapies.

Anti-inflammatory and Antitumor Activity of a Triple Therapy for a Colitis-Related Colorectal Cancer.

Colorectal cancer (CRC) is an important health issue worldwide, accounting for the third place of cancer incidence. Chronic inflammation, as seen in Crohn's disease and ulcerative colitis, is the most important risk factor for developing CRC, as it favours neoplastic transformation by enhancing epithelial cell turnover in the colonic mucosa. Treatments for CRC need to be improved; currently they are not specific and have several secondary effects in patients. The main objective of this work was to evaluate a new therapeutic strategy against a colitis-related colorectal cancer in vivo and in vitro by targeting mTOR-signaling and lactate dehydrogenase A. Together, these mechanisms directly affect tumor energetics. In this study we evaluated a better and more efficient triple therapy against a chronic inflammation-associated CRC in vivo and in vitro. After the development of tumors, mice were treated intraperitoneally during a forty-day period with single drugs or different combinations of Metformin, Sodium Oxamate and Doxorubicin. Targeted inhibition of the mTOR pathway, lactate dehydrogenase A and the concurrent use of Doxorubicin (called in this work as triple therapy), leaded to a notable reduction in the number and size of tumors in mice, and, a significant pro-inflammatory cytokines reduction Besides, we showed that treated cells were induced to early autophagy, and apoptosis cell death. Our results represent a novel and robust therapeutic strategy for overcoming CRC by means of targeting central molecular pathways in cancer by the combination of Metformin, Oxamate, and Doxorubicin leading to a rapid tumor growth inhibition and a dramatic colorectal crypt restoration. Besides, drug combination resulted in a notable reduction of anti-inflammatory cytokines.

Medicinal plants used in Mexican traditional medicine for the treatment of colorectal cancer.

ETHNOPHARMACOLOGICAL RELEVANCE: Cancer cases numbers are increasing worldwide positioning this disease as the second cause of mortality for both sexes. Medicinal plants have been used in the fight against cancer as the basis for drug discovery and nowadays more than 70% of anticancer drugs have a natural origin. Mexico is regarded for its cultural and biological diversity, which is reflected in the vast traditional knowledge of herbal remedies. In this review we examined herbal remedies employed in colorectal cancer treatment (CRC). AIM OF THE STUDY: The goal of this work was to gather scientific reports of plants used in Mexican traditional medicine for CRC treatment. MATERIALS AND METHODS: We performed a search on scientific literature databases using as keywords: "colon cancer", "gastric cancer", "cytotoxicity", studies "in vitro and in vivo", in combination with "Mexican medicinal plants" or "Mexican herbal remedies". The selection criteria of cytotoxic activity for extracts or pure compounds was based on the National Cancer Institute of USA recommendations of effective dose 50 (ED50) of ≤20µg/mL and ≤4µg/mL, respectively. RESULTS: In this review we report 25 botanic families and 39 species of plants used for the treatment of colon cancer in Mexico with evidence in studies in vitro and in vivo. CONCLUSIONS: Medicinal plants are still a great source of novel chemical structures with antineoplastic potential as it is proven in this work. The selection criteria and activity was narrowed for methodological purposes, nevertheless, drug discovery of natural origin continues to be a highly attractive R&D strategy.

Clinical evidence of the relationship between aspirin and breast cancer risk (review).

In the search for new therapeutic alternatives against cancer, either as a preventive treatment or for advanced stages, it is common to appeal to well-known drugs used for the treatment of other diseases that may interfere with the metabolic pathways involved in carcinogenesis. Non-steroidal anti-inflammatory drugs (NSAIDs) display anticancer activity through the inhibition of the COX-2 enzyme, triggering processes such as apoptosis, a reduction in proliferation and inhibition of carcinogenesis. Breast cancer is a neoplasm with the highest incidence and mortality rate among young women worldwide. Epidemiologic data have shown that drugs such as NSAIDs, particularly aspirin, reduce the relative risk of breast cancer. However, in the subgroup of responsive patients, dose, time and frequency of use have not yet been established. Here, we review the reports published during the last 10 years regarding the relationship between breast cancer and aspirin.

NF-kappaB modulators from Valeriana officinalis.

Valeriana officinalis (Valerianaceae) has been of great interest for its therapeutic uses for treating mild nervous tension and temporary sleeping problems. In traditional European medicine it has been also reported as an antiinflammatory remedy. This study reports that the EtOAc extract of the underground parts of V. officinalis showed inhibitory activity against NF-kappaB at 100 microg/mL in the IL-6/Luc assay on HeLa cells and provided protection against excitotoxicity in primary brain cell cultures at micromolar concentrations. Bioassay-guided fractionation of the EtOAc extract led to the isolation of three known sesquiterpenes: acetylvalerenolic acid (1), valerenal (2) and valerenic acid (3), 1 and 3 were active as inhibitors of NF-kappaB at a concentration of 100 microg/mL. Acetylvalerenolic acid (1) reduced NF-kappaB activity to 4%, whereas valerenic acid (3) reduced NF-kappaB activity to 25%.

Physalins from Witheringia solanacea as modulators of the NF-kappaB cascade.

Crude extracts of Witheringia solanacea leaves showed inhibition of NF-kappaB activation at 100 microg/mL induced by phorbol 12-myristate-13-acetate (PMA) in HeLa cells stably transfected with a luciferase reporter gene controlled by the IL-6 promoter. Three physalins were isolated from an active fraction, namely, physalins B (1), F (2), and D (3). Of these compounds, 1 and 2 demonstrated inhibitory activities on PMA-induced NF-kappaB activation at 16 and 8 microM and induced apoptosis after 24 h in a cell-cycle analysis using a human T cell leukemia Jurkat cell line. Compound 2 also inhibited TNF-alpha-induced NF-kappaB activation at 5 microM through the canonical pathway, but was inactive in the Tet-On-Luc assay, indicating specificity of action, although it interfered with Tet-On-Luc at higher concentrations. It is suggested that the presence of a double bond and an epoxy ring between carbons 5 and 6 in compounds 1 and 2, respectively (which are not present in compound 3), are related to their anti-inflammatory activity.