Gretel Mendoza

Dr. Gretel Mendoza

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Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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6 May 2020 in Toxins
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Journal Article
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GMGretel Mendoza
Gretel Mendoza
EIEdgar León Esparza Ibarra
Edgar León Esparza Ibarra
JAJorge Luis Ayala-Luján
Jorge Luis Ayala-Luján
MMMarisa Mercado-Reyes
Marisa Mercado-Reyes
Susana GodinaSusana Godina
Susana Godina
Jorge OlmosJorge Olmos
Jorge Olmos
Bacillus thuringiensis (Bt) is a ubiquitous bacterium in soils, insect cadavers, phylloplane, water, and stored grain, that produces several proteins, each one toxic to different biological targets such as insects, nematodes, mites, protozoa, and mammalian cells. Most Bt toxins identify their particular target through the recognition of specific cell membrane receptors. Cry proteins are the best-known toxins from Bt and a great amount of research has been published. Cry are cytotoxic to insect larvae that affect important crops recognizing specific cell membrane receptors such as cadherin, aminopeptidase-N, and alkaline phosphatase. Furthermore, some Cry toxins such as Cry4A, Cry4B, and Cry11A act synergistically with Cyt toxins against dipteran larvae vectors of human disease. Research developed with Cry proteins revealed that these toxins also could kill human cancer cells through the interaction with specific receptors. Parasporins are a small group of patented toxins that may or may not have insecticidal activity. These proteins could kill a wide variety of mammalian cancer cells by recognizing specific membrane receptors, just like Cry toxins do. Surface layer proteins (SLP), unlike the other proteins produced by Bt, are also produced by most bacteria and archaebacteria. It was recently demonstrated that SLP produced by Bt could interact with membrane receptors of insect and human cancer cells to kill them. Cyt toxins have a structure that is mostly unrelated to Cry toxins; thereby, other mechanisms of action have been reported to them. These toxins affect mainly mosquitoes that are vectors of human diseases like Anopheles spp (malaria), Aedes spp (dengue, zika, and chikungunya), and Culex spp (Nile fever and Rift Valley fever), respectively. In addition to the Cry, Cyt, and parasporins toxins produced during spore formation as inclusion bodies, Bt strains also produce Vip (Vegetative insecticidal toxins) and Sip (Secreted insecticidal proteins) toxins with insecticidal activity during their vegetative growth phase.

22 July 2021 in Cells
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Journal Article
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FMFátima Martínez-Rodríguez
Fátima Martínez-Rodríguez
JLJared E. Limones-González
Jared E. Limones-González
BMBrenda Mendoza-Almanza
Brenda Mendoza-Almanza
EIEdgar León Esparza Ibarra
Edgar León Esparza Ibarra
PGPerla Ivonne Gallegos-Flores
Perla Ivonne Gallegos-Flores
GMGretel Mendoza
Gretel Mendoza
Cancer is one of the leading public health issues worldwide, and the number of cancer patients increases every day. Particularly, cervical cancer (CC) is still the second leading cause of cancer death in women from developing countries. Thus, it is essential to deepen our knowledge about the molecular pathogenesis of CC and propose new therapeutic targets and new methods to diagnose this disease in its early stages. Differential expression analysis using high-throughput techniques applied to biological samples allows determining the physiological state of normal cells and the changes produced by cancer development. The cluster of differential molecular profiles in the genome, the transcriptome, or the proteome is analyzed in the disease, and it is called the molecular signature of cancer. Proteomic analysis of biological samples of patients with different grades of cervical intraepithelial neoplasia (CIN) and CC has served to elucidate the pathways involved in the development and progression of cancer and identify cervical proteins associated with CC. However, several cervical carcinogenesis mechanisms are still unclear. Detecting pathologies in their earliest stages can significantly improve a patient’s survival rate, prognosis, and recurrence. The present review is an update on the proteomic study of CC.

6 August 2019 in Oncology Letters
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Journal Article
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GMGretel Mendoza
Gretel Mendoza
LRLeticia Rocha‑Zavaleta
Leticia Rocha‑Zavaleta
EEEdgar Esparza‑Ibarra
Edgar Esparza‑Ibarra
Jorge OlmosJorge Olmos
Jorge Olmos
EOElizabeth Ortíz‑Sánchez
Elizabeth Ortíz‑Sánchez
CRCésar Enrique Rivas-Santiago
César Enrique Rivas-Santiago
Cervical cancer (CC) is one of the leading causes of cancer‑associated mortalities in women from developing countries. Similar to other types of cancer, CC is considered to be a multifactorial disease, involving socioeconomic, cultural, immunological and epigenetic factors, as well as persistent human papilloma virus (HPV) infection. It has been well established that cancer stem cells (CSCs) play an important role in defining tumor size, the speed of development and the level of regression following treatment; therefore, CSCs are associated with a poor prognosis. CSCs have been detected in many types of cancer, including leukemia, pancreatic, colon, esophagus, liver, prostate, breast, gastric and lung cancer. In cervical cancer, CSCs have been associated with resistance to normally used drugs such as cisplatin. The present review summarizes the strategies that high‑risk HPV viruses (HPV‑16 and HPV‑18) have developed to transform normal epithelial cells into cancer cells, as well as the cellular pathways and studies associated with the identification of cervical cancer stem cell biomarkers. In this sense, the present review provides state of the art information regarding CC development.

25 December 2022 in Current Oncology
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IAIrma Beatriz Mitre Aguilar
Irma Beatriz Mitre Aguilar
DMDaniel Moreno-Mitre
Daniel Moreno-Mitre
JMJorge Melendez-Zajgla
Jorge Melendez-Zajgla
VMVilma Maldonado
Vilma Maldonado
NJNadia Jacobo-Herrera
Nadia Jacobo-Herrera
GMGretel Mendoza
Gretel Mendoza
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.

21 March 2018 in Scientific Reports
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MTMary-Carmen Torres-Quintero
Mary-Carmen Torres-Quintero
IGIsabel Gómez
Isabel Gómez
SPSabino Pacheco
Sabino Pacheco
JSJorge Sánchez
Jorge Sánchez
HFHumberto Flores
Humberto Flores
Alejandra BravoAlejandra Bravo
Alejandra Bravo
The Cyt and Cry toxins are different pore-forming proteins produced byBacillus thuringiensisbacteria, and used in insect-pests control. Cry-toxins have a complex mechanism involving interaction with several proteins in the insect gut such as aminopeptidase N (APN), alkaline phosphatase (ALP) and cadherin (CAD). It was shown that the loop regions of domain II of Cry toxins participate in receptor binding. Cyt-toxins are dipteran specific and interact with membrane lipids. We show that Cry1Ab domain II loop3 is involved in binding to APN, ALP and CAD receptors since point mutation Cry1Ab-G439D affected binding to these proteins. We hypothesized that construction of Cyt1A-hybrid proteins providing a binding site that recognizes gut proteins in lepidopteran larvae could result in improved Cyt1Aa toxin toward lepidopteran larvae. We constructed hybrid Cyt1Aa-loop3 proteins with increased binding interaction toManduca sextareceptors and increased toxicity against two Lepidopteran pests,M. sextaandPlutella xylostella. The hybrid Cyt1Aa-loop3 proteins were severely affected in mosquitocidal activity and showed partial hemolytic activity but retained their capacity to synergize Cry11Aa toxicity against mosquitos. Our data show that insect specificity of Cyt1Aa toxin can be modified by introduction of loop regions from another non-related toxin with different insect specificity.

22 October 2012 in Oncology Letters
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GMGretel Mendoza
Gretel Mendoza
APamelia portillo
amelia portillo
Jorge OlmosJorge Olmos
Jorge Olmos
Her-2 gene amplification and its overexpression in breast cancer cells is directly associated with aggressive clinical behavior. The her-2 gene and its Her-2 protein have been utilized for disease diagnosis and as a predictive marker for treatment response to the antibody herceptin. Fluorescent in situ hybridization (FISH) and immunohistochemistry (IHC) are the most common FDA-approved methodologies involving gene and protein quantification, respectively. False positive or negative her-2/Her-2 patient results may result in inappropriate treatment administration. To support accurate quantification and interpretation of results, in this study we have standardized qPCR analysis using previously identified IHC samples, obtaining very significant and clinically useful results.