Microvesicles as promising biological tools for diagnosis and therapy

ABSTRACT

Introduction: Shed by most cells, in response to a myriad of stimuli, extracellular vesicles (EVs) carry proteins, lipids, and various nucleic acids. EVs encompass diverse subpopulations differing for biogenesis and content. Among these, microvesicles (MVs) derived from plasma membrane, are key regulators of physiopathological cellular processes including cancer, inflammation and infection. This review is unique in that it focuses specifically on the MVs as a mediator of information transfer. In fact, few proteomic studies have rigorously distinguished MVs from exosomes.

Areas covered: Aim of this review is to discuss the proteomic analyses of the MVs. Many studies have examined mixed populations containing both exosomes and MVs. We discuss MVs’ role in cell-specific interactions. We also show their emerging roles in therapy and diagnosis.

Expert commentary: We see MVs as therapeutic tools for potential use in precision medicine. They may also have potential for allowing the identification of new biomarkers. MVs represent an invaluable tool for studying the cell of origin, which they closely represent, but it is critical to build a repository with data from MVs to deepen our understanding of their molecular repertoire and biological functions.     

Oncoproteomics: current trends and future perspectives

Oncoproteomics is the application of proteomics technologies in oncology. Functional proteomics is a promising technique for the rational identification of biomarkers and novel therapeutic targets for cancers. Recent progress in proteomics has opened new avenues for tumor-associated biomarker discovery. With the advent of new and improved proteomics technologies, such as the development of quantitative proteomic methods, high-resolution, -speed and -sensitivity mass spectrometry and protein arrays, as well as advanced bioinformatics for data handling and interpretation, it is now possible to discover biomarkers that can reliably and accurately predict outcomes during cancer management and treatment. However, there are several difficulties in the study of proteins/peptides that are not inherent in the study of nucleic acids. New challenges arise in large-scale proteomic profiling when dealing with complex biological mixtures. Nevertheless, oncoproteomics offers great promise for unveiling the complex molecular events of tumorigenesis, as well as those that control clinically important tumor behaviors, such as metastasis, invasion and resistance to therapy. In this review, the development and advancement of oncoproteomics technologies for cancer research in recent years are expounded.     

Current progress in protein profiling of complex samples

Accurate cancer biomarkers are needed for early detection, disease classification, prediction of therapeutic response and monitoring treatment. While there appears to be no shortage of candidate biomarker proteins, a major bottleneck in the biomarker pipeline continues to be their verification by enzyme linked immunosorbent assays. Multiple reaction monitoring (MRM), also known as selected reaction monitoring, is a targeted mass spectrometry approach to protein quantitation and is emerging to bridge the gap between biomarker discovery and clinical validation. Highly multiplexed MRM assays are readily configured and enable simultaneous verification of large numbers of candidates facilitating the development of biomarker panels which can increase specificity. This review focuses on recent applications of MRM to the analysis of plasma and serum from cancer patients for biomarker verification. The current status of this approach is discussed along with future directions for targeted mass spectrometry in clinical biomarker validation.     

Proteomics and metabolomics in cancer drug development

In this review article, the main recent advancements in the field of proteomics and metabolomics and their application in cancer research are described. In the second part of the review the main metabolic alterations observed in cancer cells are thoroughly dissected, especially those involving anabolic pathways and NADPH-generating pathways, which indirectly affect anabolic reactions, other than the maintenance of the redox poise. Alterations to mitochondrial pathways and thereby deriving oncometabolites are also detailed. The third section of the review is a discussion of how and to what extent (mutations to) tumor suppressors and oncogenes end up influencing cancer cell metabolism and cell fate, either promoting survival and proliferation or autophagy and apoptosis. In the last section of the review, an overview is provided of therapeutic strategies that make use of metabolic reprogramming approaches.     

Proteomics advances for precision therapy in ovarian cancer

ABSTRACT

Introduction: Due to the relatively low mutation rate and high frequency of copy number variation, finding actionable genetic drivers of high-grade serous carcinoma (HGSC) is a challenging task. Furthermore, emerging studies show that genetic alterations are frequently poorly represented at the protein level adding a layer of complexity. With improvements in large-scale proteomic technologies, proteomics studies have the potential to provide robust analysis of the pathways driving high HGSC behavior.

Areas covered: This review summarizes recent large-scale proteomics findings across adequately sized ovarian cancer sample sets. Key words combined with ‘ovarian cancer’ including ‘proteomics’, ‘proteogenomic’, ‘reverse-phase protein array’, ‘mass spectrometry’, and ‘adaptive response’, were used to search PubMed.

Expert opinion: Proteomics analysis of HGSC as well as their adaptive responses to therapy can uncover new therapeutic liabilities, which can reduce the emergence of drug resistance and potentially improve patient outcomes. There is a pressing need to better understand how the genomic and epigenomic heterogeneity intrinsic to ovarian cancer is reflected at the protein level and how this information could be used to improve patient outcomes.     

Case of lung carcinoma revealed by vulvar metastasis associated with systemic scleroderma and literature review

Metastatic carcinoma to the vulva is rare, where the incidence is believed to be between 5% and 8%.However, malignant tumors have been described in 3–11% of systemic scleroderma (SSc) cases.We report the case of one patient, a 66-year-old postmenopausal woman, whose medical history was marked with rheumatic vascular disease (systemic scleroderma) since 1993 without muscular, renal, cardiac lesions or HTA (arterial hypertension) and without tobacco history.The woman presented with a new vulvar mass of the right labia in December 2011 that had progressively enlarged in size.CT scan of the abdominopelvic region demonstrated a lobular mass of the right labia with central necrosis, 7 cm on the wide axis, and the rectum and the vaginal wall were normal. No inguinal or iliac lymphadenopathy was noted.An outpatient excisional biopsy revealed a poorly differentiated malignant tumor suggestive of carcinoma.IHC: CK7+/CK20−, estrogen receptors−, AE 1 AE 3+, vimentine+, S100−, Desmina−, CD34−, KI 67: 20%.The thoracic scan revealed a large mass of 4 cm × 3 cm in the right lung base with right paratracheal lymphadenopathy 3 cm × 2 cm.A bronchoscopy revealed discrete stenosis of the mediastinal portion of the right bronchial tree.The bronchial biopsy also revealed poorly differentiated lung carcinoma, non-small cell, which was identical with the vulvar tumor.

Conclusion

The presence of the single lung lesion with only one lymphadenopathy paratracheal with pathological and immunohistochemical (IHC) profile similar to the vulvar lesion, and a particular IHC profile with CK7+ and CK20− was detected – that is more specific to the primitive pulmonary cancer, and the presence of only one sarcoma marker vementine+, desmine and actine−. Also the presence of KI 67: 20%, predicted the proliferative and great metastatic power of the lung tumor was observed.Additionally, lung cancer was the most frequent type and may develop in scleroderma as reported in most studies.This allows to conclude for primitive lung carcinoma revealed with vulvar metastasis after elimination of the possibility of vulvar sarcoma.The patient was treated by chemotherapy (Taxol/Platin) with partial response from the lung after 3 cycles and palliative radiotherapy in the vulva with a good response.This case described primary lung carcinoma associated with scleroderma, revealed by a vulvar metastasis, which may be related to the aggressiveness of lung cancer when the lung fibrosis follow-up is not performed well to detect early the development of lung tumors in the patient with systemic scleroderma.     

Prognostic factors and survival in metastatic breast cancer: A single institution experience

Background

The current retrospective study aims to identify some determinants of survival in metastatic breast cancer.

Methods

The study concerned 332 patients with synchronous (SM) or metachronous (MM) metastatic breast cancer treated between January 2000 and December 2007. Statistical comparison between subgroups of patients concerning survival was carried out employing log-rank test for the invariable analysis and Cox model for the multivariable analysis. Factors included: age group (≤50 years vs. >50; ≤70 years vs. >70; ≤35 years vs. >35), menopausal status, presentation of metastatic disease (SM vs. MM), disease free interval (DFI) (≤24 months vs. >24 months; ≤60 months vs. >60 months), performance status at diagnosis of metastatic disease (PS) (0–1 vs. >1), hormone receptors (HR), number of metastatic sites (1 site vs. >1), nature of the metastatic site (visceral vs. non visceral), first line therapy, surgery of the primary tumor (SPT), locoregional radiotherapy (LRRT) and use or not of bisphosphonates.

Results

Overall survival at 5 years was 12%. Positive prognostic factors in univariate analysis were: age ≤ 70 years, hormono-dependence of the tumor, good PS (PS 0–1), less than two metastatic sites, no visceral metastases, DFI ≥ 24 months, SPT or LRRT. In multivariate analysis, favorable independent prognostic factors included: good PS (PS 0–1), absence of visceral metastases (liver, lung, brain) and age ≤ 70 years.

Conclusion

Many of the prognostic factors in metastatic breast cancer found in our study are known in the literature but some of them, like the application of locoregional treatment (radiotherapy or surgery) and the use of bisphosphonates, need to be further investigated in randomized clinical trials.     

3D conformal hypofractionated radical radiotherapy in early glottic cancer

Aim

The purpose of this study was to evaluate acute and late toxicity and the locoregional control in patients treated with hypofractionated radical radiotherapy 2.25 Gy/fraction/day for early glottic carcinoma.

Materials and methods

A retrospective analysis was performed of 27 patients, stage T1–T2 N0 glottic squamous cell carcinoma, that underwent radical RT from April 2008 to October 2011. The mean age was 64.6 years (range 36–81). Seventeen patients were staged T1a, 3 patients T1b and 7 patients T2. All patients were 3D planned and treated in a 6 MV LINAC, 2.25 Gy/fraction/5 days per week, to a total dose between 63 Gy and 67.5 Gy. Biological Effective Dose (BED (α/β = 10)) ranged from 77.18 Gy to 82.69 Gy and EQD2 from 64.31 Gy to 68.91 Gy. Patients were evaluated in periodic follow-up. Toxicity was evaluated according to RTOG Toxicities Scales.

Results

With a median follow-time of 24.7 months (range 3.6–44.2 months), no evidence of locoregional recurrence was observed. The treatment was well tolerated and no unscheduled interruptions in treatments for toxicity were documented, with the median overall treatment time of 41 days (range 38–48). Only grades 1 and 2 acute toxicity were observed and no evidence of severe late toxicity.

Conclusion

The authors believe that this moderately hypofractionated scheme can provide a good locoregional control for T1–T2 glottic carcinomas with no increase of toxicity. As the limitation of this work is the reduced number of patients and the lack of long term follow-up, the authors hope to update this retrospective study in the future in order to improve the power of the results.     

Current status of IMRT in head and neck cancer

Background

IMRT provides highly conformal dose distributions creating non uniform spatial intensity using different segments in the beam.

Material & Methods and Results

Different retrospective studies have shown a high capability of IMRT to treat tumours close to the base of skull. Prospective studies have shown a decrease in xerostomia compared with conventional 3D conformal treatment (3DCRT). Modulation of intensity is performed by the movement of the multileaf collimator (MLC) that can deliver the radiation in different ways, such as static field segments, dynamic field segments and rotational delivery (arc therapy and tomotherapy). There are slight differences among the different techniques in terms of homogeneity, dose conformity and treatment delivery time.

Conclusions

The best method to deliver IMRT will depend on multiple factors such as deliverability, practicality, user training and plan quality.     

Difference in Ki67 and Thymidylate Synthase Expression in Primary Tumour Compared with Metastatic Nodes in Breast Cancer Patients

Breast cancer is a heterogeneous disease, so therapeutic predictive biological markers need to be identified. To date an accurate evaluation of predictive markers is mainly done at the primary site; however, the main goal of adjuvant therapy for breast cancer is the control of micrometastases. The aim of this study is to assess as therapeutic and/or prognostic marker, the proliferation status of primary tumors and involved nodes as measured by Ki67 and thymidylate synthase (TS) expression, in 30 breast cancer node positive patients. TS is the main target of 5-fluorouracil (5-FU) activity, and its overexpression is one of the mechanisms of 5-FU drug resistance; however, in some studies its absence is responsible for a worse response to 5-FU. Our results show that malignant cells of involved nodes were in a post mitotic phase of the cell cycle, and show a low proliferation index and TS expression, while the primary tumours and controls, were strongly positive. On these basis we can hypothesize that these cells could be less sensitive to 5-FU. Further studies are necessary to identify other mechanisms responsible for their metastasing capability and/or for their aggressiveness.