Cancer Research – Institute of Research and Advanced Training in Health Sciences and Technologies

GROUP LEADER | MAJOR INTERESTS | RESEARCH TEAM | CURRENT PROJECTS | RELEVANT PUBLICATIONS

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GROUP LEADER
Hassan Bousbaa | ORCID

MAJOR INTERESTS
We are investigatin the mechanisms of cell division (mitosis) in somatic cells in order to understand how errors in chromosome segregation arise and lead to genomic instability in cancer. The clinical relevance of this information is exploited to identify novel diagnostic and prognostic markers, particularly for oral cancer, as well as to identify novel therapeutic strategies to kill cancer cells or to increase their sensitivity to anti-mitotic agents.

Specifically we aim at:

Unveiling the mechanisms of the spindle assembly checkpoint (a surveillance mechanism for accurate chromosome segregation)
Screening for anti-mitotic small interfering RNAs (siRNAs) to overcome resistance to anti-mitotic agents
Screening for novel anti-mitotic compounds that could be used as alternative to or in combination with current anti-cancer drugs
Identifying novel diagnostic and prognostic markers for oral cancer

MSc Students
Carmen Mariana Machado | ccmmariana3@hotmail.com | ORCID

BSc Students
José Diogo Pinto de Almeida | diogoalmeida14@hotmail.com | ORCID

Research Fellowship
Diana Ribeiro | diana.ribeiro@cespu.pt | ORCID

Research Technician
Patrícia Silva | patricia.silva@cespu.pt | ORCID

CURRENT PROJECTS

Project PTDC/MAR-BIO/4694/2014 e POCI-01-0145-FEDER-016790: Navigating through marine-derived fungi: bioprospection and synthesis of bioactive secondary metabolites and analogues as chemotherapic agents | PI: Madalena Pinto | Team: Madalena Pinto, Alexandra Viana da Costa, Ana Catarina Alves, Ana Sara Gomes, Anake Kijoa, Carla Fernandes, Carlos Afonso, Chadaporn Prompanya, Cláudia Nunes, Cláudia Marques, Cláudia Bessa, Domingos Ferreira, Hassan Bousbaa, Honorina Cidade, Isabel Carvalho, Joana Fonseca, J. Soares, Liliana Raimundo, Lucília Saraiva, Lucinda Bessa, Maraia de Fátima Cerqueira, Salette Reis, Maria Elizabeth Tiritan, Emília Sousa, Eugénia Pinto, Maria Cruz, Marta Correia-da-Silva, Nelson Gomes, Silva, P., Paulo Costa, Sandra Marques, Sara Cravo, War Zin| Funding Entity: FEDER, FCT | Period covered:

The need for a continued search for new anti-infective and anticancer drugs is universally considered of great importance since many of the current drugs are insufficiently effective, highly toxic, and resistances may be developed. Our group has isolated two alkaloids, eurochevalierine, a potent inhibitor of the growth of human tumor cell lines [1], from the soil fungus Neosartorya pseudofischeri, and neofiscalin A from the soil and marine fungus N. siamensis with potent antibacterial activity [2]. Neofiscalin A exhibited also antibiofilm activity in both reference and multidrugs-resistant isolates, and is currently in the patent filing process. On the other hands, marine fungi derived xanthones, particularly yicathins and isomers were considered promising as chemotherapic agents [3]. So, eurochevalierine, neofiscalin A and yicathins can be considered very interesting models to discover new anti-infective and anticancer drugs to overcome drug-resistance that could represent innovative drug candidates. However, their availability to proceed to further investigations and their complex structures could limit their future as drug candidates. Our group has multi- and transdisciplinary skills, with a large experience in isolation and structure elucidation of natural products, synthesis, cellular and molecular biology and nanotechnology. Moreover, the synthesis of anti-infective [4,5] and antitumor [6-10] xanthone derivatives, particularly in multidrugs-resistant models [5,10], is the strength of our group. Therefore, this expertise can drive these natural products and derivatives with enough potency and selectivity to become new potential anti-infective/antitumor clinical candidates. However, our goal is not only to continue with the search for innovative marine-derived compounds but also to obtain derivatives/formulations of the most promising compounds to obtain more efficient analogues. To achieve these goals, five approaches will be undertaken: i) isolate other bioactive compounds from the marine-derived N. pseudofischeri and N. siamensis and other related strains; ii) synthesize eurochevalierine, neofiscalin A and yicathins to obtain more quantity of these products for in vitro and in vivo tests, iii) carry out successive molecular modifications in order to achieve more efficient analogues, iv) investigate their potential as anti-infective agents, v) perform in vitro studies in tumor cell lines; vi) incorporate in nanoparticles in order to improve permeability and selectivity of the most promising compounds. To carry out approach i) isolation of the bioactive metabolites, we will culture the fungi N. pseudofischeri and N. siamensis, isolated from the marine environment, such as sponge or coral to obtain eurochevalierine, neofiscalin A, and structurally related alkaloids. Moreover, we will also perform a co-culture of these two fungi with marine bacteria for the purpose of increasing the quantity of the alkaloids eurochevalierine and neofiscalin A as well as to verify if the fungi also accumulate other bioactive metabolites when compared to the pure cultures. To carry out approaches ii)-iii) these alcaloids and yicathins will be synthesized and the (semi)synthesized derivatives will be used to obtain a library of structurally-related analogues with improved efficacy. These results will allow us to establish structure activity relationships (SAR), to contribute to define the important molecular features of anti-infective and antitumor activities, and consequently, the design of more potent molecules. To carry out approach iv), the new compounds will be screened for antimicrobial activity using the agar disk diffusion assay and/or the broth microdilution method. These compounds will be also tested for their synergy with antibiotics, against isolates presenting resistance towards those antimicrobials, using the broth microdilution Checkerboard method. Compounds showing antimicrobial activity will be then tested for their ability to inhibit the biofilm formation. To screen for compounds with anti-parasitic activity their effect will be evaluated for Cryptosporidium inhibitory growth via human epithelial cells lines. To carry out approach v), the compounds will be screened for their in vitro growth inhibitory activity in human tumor cell lines. The elucidation of the molecular mechanism of antitumor activity of the most promising compounds will be performed, particularly alterations in cellular proliferation, cell cycle, mitosis, and apoptosis, analysis of the effect on tumor immune microenvironment, and identification of protein targets. To carry out approach vi), the compounds with promising anti-infective/antitumor activity will be incorporated into biodegradable and biocompatible LNP formulations by several methods, and technological parameters will be studied. This approach will allow us to verify if LNP formulations can improve the bioavailability and/or activity/selectivity of the bioactive compounds.

Project AdOralLeuk-CESPU-2016: Deregulation of cell-cell adhesion proteins in malignant transformation of oral leukoplakias. | PI: Luís Monteiro | Team: Luís Monteiro, Barbas do Amaral, Patrícia Silva, Leonor Delgado, Sandra Marques, José Júlio Pacheco | Funding Entity: CESPU | Period covered: from 04-2016 to 03-2017

Oral leukoplakia (OLEP) is one of the most common potentially malignant disorders and precedes oral cancer in more than 50% of the cases. Nevertheless, there are no markers that can predict accuraly which OLEP will transform to oral cancer. In previous studies, we have shown that there are some characteristic markers, including MMP-9, or podoplanin, that are deregulated in oral cancer even in early stages of the disease. One of the key-points for malignant transformation of OLEP is the cell-cell attachment loss and invasion of these epithelial cells to connective tissue. However, few studies have analyzed cell-cell adhesion proteins deregulation in these lesions. Some of these molecules have been implicated in carcinogenesis and dissemination of several cancers including claudins, ocludins, or E-cadherin. Our aim in this study is to identity molecular factors related with cell-cell attachment deregulation that could be related with the risk of malignant transformation of OLEP. The aim could contribute significantly to the decisions of clinicians regarding the different possibilities of treatment (only follow-up, conservative or radical treatment) of OLEP.

Project MitOralC-CESPU-2016: Clinicopathological significance of Spindly and Bub3 proteins expression in oral squamous cell carcinomas. | PI: Luís Monteiro | Team: Luís Monteiro, Hassan Bousbaa, Patrícia Silva, Leonor Delgado, Sandra Marques | Funding Entity: CESPU | Period covered: from 04-2016 to 03-2017

There is a strong need in understanding the molecular mechanism underlying oral cancer development and progression and identifying specific biomarkers for early detection, effective prognosis, better management, and improved treatment outcomes of oral cancer. In this context, proteins that act during mitosis have not been explored and we believe could be potential cancer biomarkers for diagnosis and prognosis.
Recently in our group, the mitotic proteins Bub3 and, although still preliminary, Spindly were shown to be overexpressed in cancer cell lines. Interestingly, their inhibition blocked cancer cell proliferation, and potentiated the chemosensitivity to anticancer drugs in an vitro system. Here we want to study the relevance of these results to patients with oral cancer. Therefore, our aims are to characterize the expression pattern of Bub3 and Spindly in patients with oral squamous cell carcinomas and evaluate this expression with clinico-pathological features, proliferative activity and survival variables.
The results of this work could be of important significance in these tumors not only with a prognostic value but also for molecular therapies.

Project SpindlyTarget-CESPU-2016: The Mitotic Protein Spindly as a Cancer Therapeutic Target. | PI: Hassan Bousbaa | Team: Hassan Bousbaa, Patrícia Silva, Vanessa Nascimento, Sandra Marques, Filipa Martins| Funding Entity: CESPU | Period covered: from 04-2016 to 03-2017

Interfering with mitosis in cancer cells leads to mitotic arrest and, very often, to cell death. This explains the proven success of the antimicrotubule drugs, taxanes and vinca alkaloids, in the clinical treatment of many cancers. However, their clinical efficacy has been impaired by various side effects and drug resistance, highlighting the need of search for new anticancer agents. In this context, non-structural components of mitosis have recently emerged as potential drug targets for therapy.
In a study aiming at screening mitotic components with potential anticancer effects, we identified the protein Spindly whose inhibition induced massive cell death in glioblastoma cancer lines. This prompted us to define as principal goal of the present proposal: i) to test the antimitotic activity of Spindly inhibition in a panel of human cancer lines in order to evaluate its broad-spectrum anticancer activity; ii) to determine if Spindly inhibition sensitizes cancer cells to taxol in a combination therapy; and iii) to elucidate the mechanistic by which Spindly inhibition induces cancer cell death.
This will be the first report of the mitotic protein Spindly as target for cancer therapy.

RELEVANT PUBLICATIONS

Teixeira J, Silva P, Faria J, Ferreira I, Duarte P, Delgado M, Queirós O, Moreira R, Barbosa J, Lopes C, Amaral Jd, Monteiro L, Bousbaa H

.2015

. Clinicopathologic significance of BubR1 and Mad2 overexpression in oral cancer. (Journal Article)

Oral Dis, .DOI: 10.1111/odi.12335.