Ciência e terapia do câncer

Cathepsin B is a ubiquitous and tightly controlled cysteine protease having been implicated in a wide variety of cellular processes such as protein conversion, activation, and signaling. Cathepsin B has also been found to have many roles in several stages of tumor progression up to and beyond metastasis. As a result, current research has focused on either identifying potential cathepsin B inhibitors that can directly be used for treatment or as a model for drug development. Development of cathepsin B inhibitors is still in progress with none currently reaching clinical trials. Some drugs such as VBY-825 and the quinolone antibiotic nitroxoline have shown promise in direct application, while others such as chalcones, curcumin, and IGFBP-4 can be used as models for developing future cathepsin B inhibitors for clinical use. Drugs already successful in clinical trials to treat other conditions unrelated to cathepsin B, such as osteoporosis with odanacatib, have similar analogues that have been shown to inhibit cathepsin B and not only could be used as a model for new cathepsin B inhibitor development, but also result in reaching the market sooner due to a known high safety profile. Further studies beyond developing cathepsin B inhibitors should focus on a combinatory treatment of cathepsin B inhibitor with chemotherapy, radiation, and/ or inhibition of other proteins involved with tumor progression. This combinatory approach has been shown to be highly effective in tumor cell sensitization and death.

Mitochondrial biogenesis (MtBIO) is the utmost requisite for cell’s replication and survival, and it has been found to be involved in chemoresistance. The chemoresistance is the foremost obstacle in the treatment of patients with ovarian cancer. Several studies showed that modulation of MtBIO can lead to cancer cell death. Therefore targeting MtBIO in ovarian cancer could be a promising therapeutic approach possibly through overcoming the chemoresistance. Potential targets of MtBIO will be discussed focusing on ovarian cancer in this review.

As next generation sequencing (NGS) technology has already become a regular fixture in research, it is now time for clinical environments to also reap the benefits of such technology. Indeed, the rich promise of NGS has the potential to be translated into improved patient care. However, there is still doubt about the widespread use of NGS in clinical diagnostics. Before implementation, there must be consensus on which analytical pipeline to use, with follow-up confirmation of variants with the gold standard: Sanger sequencing.

Here, we present a NGS analytical pipeline that has complete agreement on 341 variants with Sanger sequencing and that is already being used in our clinical diagnostic laboratory in the National Health Service England for the regular screening of inherited, pathogenic variants. Details on our NGS and other services can be found at http://www.sheffieldchildrens.nhs.uk/our-services/sheffield-diagnostic-genetics-service/. Our pipeline broadly follows the ‘best practices’ guidelines set by the GATK at the Broad Institute, with a novel added approach involving randomly selecting subsets of reads and later merging variants called from each. This allows for falsenegatives to be eliminated with a high level of confidence. Moreover, modeling reduced depth of coverage reveals that 30X is the point at which false-positives are eliminated with >99.9% confidence.

Our results allude to a fine balance between read-depth and error, and we believe that our pipeline will increase confidence in NGS and permit its gradual enrollment in clinical diagnostic laboratories.

Introduction: Lifeguard (LFG) is an anti-apoptotic protein that inhibits programmed cell death mediated by Fas in tumour cells. The exact mechanism of action and the molecular function from LFG in the carcinogenesis of human breast cells is not clear. But the expression of LFG mRNA correlates with LEF-1 transcription factor activity.

Methods: In the present study, chemotherapeutic-induced apoptotic effects were studied using MCF-7 cells as an in vitro test model. Molecular (Western blot and RT-PCR) techniques were used to investigate LFG expression. To investigate the breast cancer cell proliferation in presence of siRNA-LFG we performed fluorescent cell viability assays.

Results: The results indicated that, a decrease of LFG expression using siRNA correlates with an increased sensitivity to Trastzumab and Erlotinib. Moreover, cell cycle analysis of LEF-1 siRNA-transfected human breast cancer cells revealed a significant arrest in G2 phase.

Conclusion: Taken together, our results indicate a pivotal role of LFG in the regulation of apoptosis in MCF-7 breast cancer cells.

Background and objective: The androgen receptor (AR) is a member of the steroid receptor subfamily with well-known biological and therapeutic importance in prostate cancer. There is evidence that the androgen signalling pathway may play a critical role also in normal and malignant breast tissue. They are highly expressed in triple negative breast cancer (TNBC) but it is not clear if AR expression is correlated with survival in advanced TNBC. Therefore, in the present study we investigated the prognostic value of AR expression in metastatic TNBC.

Patients and methods: Stage IV TNBC was included in the analysis. Patients with poor performance status (ECOG>2) were excluded. Tumors with >10% nuclear-stained cells were considered to be positive for AR. Univariate and multivariate analyses were performed.

Results: From a database of 208 TNBC patients, 24 cases of advanced TNBC were identified; out of 24 patients, 33% were AR positive. The median age at diagnosis was 61 years (range 30-78 years). All patients included in the study received first-line chemotherapy for their disease. Median progression free-survival (mPFS) and overall survival (OS) were 3.5 months (range 0.3-27.3 months) and 25.9 months (range 2.52-122.2 months), respectively. Univariate analysis showed that AR negative advanced TNBC had a significantly worse PFS (3.2 vs 7.9 months; p=0.02; HR=2.57, 95% CI 1.15-10.53) and OS (20.5 vs 47.4 months; p=0.01; HR=2.88, 95% CI 1.32- 9.43). Multivariate analysis confirms that AR expression was an independent prognostic factor of PFS (p=0.04; HR=2.19, 95% CI 1.52-5.91), as well as for OS (p=0.05; HR=2.21, 95% CI 0.98-2.55).

Conclusions: Our preliminary results suggested that the assessment of AR expression may be a useful tool to identify patients with a good or a poor prognosis. Furthermore, since that about one third of metastatic TNBC expressed ARs, they may represent a target for novel potential treatment options in advanced TNBC.

Purpose: The aim of this study was to compare the plan results that were obtained by using different calculation grid sizes ranging from 3 mm to 10 mm, and the same dose calculation algorithm Pencil Beam (PB), in Intensity Modulated Radiotherapy (IMRT) for different treatment sites Head-And –Neck, Pelvis (Carcinoma Cervix) And Brain Cancers. Introduction: Ever since the advent and development of treatment planning systems, the uncertainty associated with calculation grid size has been an issue. Even to this day, with highly sophisticated 3D conformal and intensity-modulated radiation therapy (IMRT) treatment planning systems (TPS), dose uncertainty due to grid size is still a concern. Materials and methods: Twelve patients in which four patients of Head-And –Neck, Pelvis And Brain tumors respectively were considered for the study. IMRT Plans were generated for a 6,600cGy, 5,000cGy & 5,400cGy prescribed doses for Head-And –Neck, Pelvis and Brain tumors respectively using Oncentra v 4.3 TPS. For each patient, dose calculation with Pencil Beam (PB) algorithms using dose grid sizes of 3.0 mm, 5.0 mm, and 10.0 mm were performed. Results: The plans were evaluated as per the ICRU guidelines and dose constraints were maintained as per the Quantec guidelines. The dose differences for the varying grid sizes in Tumor Volumes and Organs at Risk were analyzed and tabulated. Conclusion: Overall, the effect of varying grid size on dose variation appears to be insignificant. However, 3 mm is recommended to ensure acceptable dose calculations, especially in high gradient regions.

The quantification of angiogenic and linfangiogenic factors has been explored in an attempt to predict the prognosis of various malignancies. In gastric cancer (GC), a promising parameter is the microvessel density (MVD).
Objective: The aim of our study is to evaluate the different methods used for its quantification. Methods: 52 cases of GC were labeled by immunohistochemistry for CD34, CD105 and D2-40. The quantification of the microvasculature was performed for each marker by counting microvessels (mv) in three “hot spots”, using three different microscopic magnifications (100x, 200x and 400x). MVD was then calculated by dividing the number of vessels by the microscopic field area (measured in mm2) and compared between the three different evaluations.
Results: the MVD obtained for CD34 was 203 mv/mm2 (100x), 311 mv/mm2 (200x) and 490 mv/mm2 (400x). The MVD score for CD105 was 127 mv/mm2 (100x), 213 mv/mm2 (200x) and 347 mv/mm2 (400x). The MVD obtained for D2-40 was 35 mv/mm2 (100x), 69 mv/mm2 (200x) and 170 mv/mm2 (400x). We found that MVD obtained in 100x magnification was lower than 200x, which was lower than in 400x. Those differences were statistically significant and occurred in a proportional way for all three markers. MVD obtained for CD34 was higher than for CD105. The MVD for lymphatics obtained by D2-40 was lower than the MVD for CD34 and CD105.
Conclusion: Our results show that the lack of standardized methods for assessing angiogenesis and lymphangiogenesis in GC can produce variations in the MDV value, impairing the reproducibility of the results and the comparison between different studies and populations. It is necessary to standardize the MVD determination methods to compare results and confirm its prognostic value in GC and in other types of tumors.