Significance of flavonoids targeting PI3K/Akt/HIF-1α signaling pathway in therapy-resistant cancer cells - A potential contribution to the predictive, preventive, and personalized medicine

BACKGROUND

Cancer management faces multiple obstacles, including resistance to current therapeutic approaches. In the face of challenging microenvironments, cancer cells adapt metabolically to maintain their supply of energy and precursor molecules for biosynthesis and thus sustain rapid proliferation and tumor growth. Among the various metabolic adaptations observed in cancer cells, the altered glucose metabolism is the most widely studied. The aberrant glycolytic modification in cancer cells has been associated with rapid cell division, tumor growth, cancer progression, and drug resistance. The higher rates of glycolysis in cancer cells, as a hallmark of cancer progression, is modulated by the transcription factor hypoxia inducible factor 1 alpha (HIF-1α), a downstream target of the PI3K/Akt signaling, the most deregulated pathway in cancer.

AIM OF REVIEW

We provide a detailed overview of current, primarily experimental, evidence on the potential effectiveness of flavonoids to combat aberrant glycolysis-induced resistance of cancer cells to conventional and targeted therapies. The manuscript focuses primarily on flavonoids reducing cancer resistance via affecting PI3K/Akt, HIF-1α (as the transcription factor critical for glucose metabolism of cancer cells that is regulated by PI3K/Akt pathway), and key glycolytic mediators downstream of PI3K/Akt/HIF-1α signaling (glucose transporters and key glycolytic enzymes).

KEY SCIENTIFIC CONCEPTS OF REVIEW

The working hypothesis of the manuscript proposes HIF-1α - the transcription factor critical for glucose metabolism of cancer cells regulated by PI3K/Akt pathway as an attractive target for application of flavonoids to mitigate cancer resistance. Phytochemicals represent a source of promising substances for cancer management applicable to primary, secondary, and tertiary care. However, accurate patient stratification and individualized patient profiling represent crucial steps in the paradigm shift from reactive to predictive, preventive, and personalized medicine (PPPM / 3PM). The article is focused on targeting molecular patterns by natural substances and provides evidence-based recommendations for the 3PM relevant implementation.

Phytochemical-based nanodrugs going beyond the state-of-the-art in cancer management-Targeting cancer stem cells in the framework of predictive, preventive, personalized medicine

Cancer causes many deaths worldwide each year, especially due to tumor heterogeneity leading to disease progression and treatment failure. Targeted treatment of heterogeneous population of cells - cancer stem cells is still an issue in protecting affected individuals against associated multidrug resistance and disease progression. Nanotherapeutic agents have the potential to go beyond state-of-the-art approaches in overall cancer management. Specially assembled nanoparticles act as carriers for targeted drug delivery. Several nanodrugs have already been approved by the US Food and Drug Administration (FDA) for treating different cancer types. Phytochemicals isolated from plants demonstrate considerable potential for nanomedical applications in oncology thanks to their antioxidant, anti-inflammatory, anti-proliferative, and other health benefits. Phytochemical-based NPs can enhance anticancer therapeutic effects, improve cellular uptake of therapeutic agents, and mitigate the side effects of toxic anticancer treatments. Per evidence, phytochemical-based NPs can specifically target CSCs decreasing risks of tumor relapse and metastatic disease manifestation. Therefore, this review focuses on current outlook of phytochemical-based NPs and their potential targeting CSCs in cancer research studies and their consideration in the framework of predictive, preventive, and personalized medicine (3PM).

Flavonoids attenuate cancer metabolism by modulating Lipid metabolism, amino acids, ketone bodies and redox state mediated by Nrf2

Metabolic reprogramming of cancer cells is a common hallmark of malignant transformation. The preference for aerobic glycolysis over oxidative phosphorylation in tumors is a well-studied phenomenon known as the Warburg effect. Importantly, metabolic transformation of cancer cells also involves alterations in signaling cascades contributing to lipid metabolism, amino acid flux and synthesis, and utilization of ketone bodies. Also, redox regulation interacts with metabolic reprogramming during malignant transformation. Flavonoids, widely distributed phytochemicals in plants, exert various beneficial effects on human health through modulating molecular cascades altered in the pathological cancer phenotype. Recent evidence has identified numerous flavonoids as modulators of critical components of cancer metabolism and associated pathways interacting with metabolic cascades such as redox balance. Flavonoids affect lipid metabolism by regulating fatty acid synthase, redox balance by modulating nuclear factor-erythroid factor 2-related factor 2 (Nrf2) activity, or amino acid flux and synthesis by phosphoglycerate mutase 1. Here, we discuss recent preclinical evidence evaluating the impact of flavonoids on cancer metabolism, focusing on lipid and amino acid metabolic cascades, redox balance, and ketone bodies.

Antithrombotic and antiplatelet effects of plant-derived compounds: a great utility potential for primary, secondary, and tertiary care in the framework of 3P medicine

Thromboembolism is the third leading vascular disease, with a high annual incidence of 1 to 2 cases per 1000 individuals within the general population. The broader term venous thromboembolism generally refers to deep vein thrombosis, pulmonary embolism, and/or a combination of both. Therefore, thromboembolism can affect both – the central and peripheral veins. Arterial thromboembolism causes systemic ischemia by disturbing blood flow and oxygen supply to organs, tissues, and cells causing, therefore, apoptosis and/or necrosis in the affected tissues. Currently applied antithrombotic drugs used, e.g. to protect affected individuals against ischemic stroke, demonstrate significant limitations. For example, platelet inhibitors possess only moderate efficacy. On the other hand, thrombolytics and anticoagulants significantly increase hemorrhage. Contextually, new approaches are extensively under consideration to develop next-generation antithrombotics with improved efficacy and more personalized and targeted application. To this end, phytochemicals show potent antithrombotic efficacy demonstrated in numerous in vitro, ex vivo, and in vivo models as well as in clinical evaluations conducted on healthy individuals and persons at high risk of thrombotic events, such as pregnant women (primary care), cancer, and COVID-19-affected patients (secondary and tertiary care). Here, we hypothesized that specific antithrombotic and antiplatelet effects of plant-derived compounds might be of great clinical utility in primary, secondary, and tertiary care. To increase the efficacy, precise patient stratification based on predictive diagnostics is essential for targeted protection and treatments tailored to the person in the framework of 3P medicine. Contextually, this paper aims at critical review toward the involvement of specific classes of phytochemicals in antiplatelet and anticoagulation adapted to clinical needs. The paper exemplifies selected plant-derived drugs, plant extracts, and whole plant foods/herbs demonstrating their specific antithrombotic, antiplatelet, and fibrinolytic activities relevant for primary, secondary, and tertiary care. One of the examples considered is antithrombotic and antiplatelet protection specifically relevant for COVID-19-affected patient groups.

Anti-breast cancer effects of phytochemicals: primary, secondary, and tertiary care

Breast cancer incidence is actually the highest one among all cancers. Overall breast cancer management is associated with challenges considering risk assessment and predictive diagnostics, targeted prevention of metastatic disease, appropriate treatment options, and cost-effectiveness of approaches applied. Accumulated research evidence indicates promising anti-cancer effects of phytochemicals protecting cells against malignant transformation, inhibiting carcinogenesis and metastatic spread, supporting immune system and increasing effectiveness of conventional anti-cancer therapies, among others. Molecular and sub-/cellular mechanisms are highly complex affecting several pathways considered potent targets for advanced diagnostics and cost-effective treatments. Demonstrated anti-cancer affects, therefore, are clinically relevant for improving individual outcomes and might be applicable to the primary (protection against initial cancer development), secondary (protection against potential metastatic disease development), and tertiary (towards cascading complications) care. However, a detailed data analysis is essential to adapt treatment algorithms to individuals’ and patients’ needs. Consequently, advanced concepts of patient stratification, predictive diagnostics, targeted prevention, and treatments tailored to the individualized patient profile are instrumental for the cost-effective application of natural anti-cancer substances to improve overall breast cancer management benefiting affected individuals and the society at large.

Protective Effects of Flavonoids Against Mitochondriopathies and Associated Pathologies: Focus on the Predictive Approach and Personalized Prevention

Multi-factorial mitochondrial damage exhibits a “vicious circle” that leads to a progression of mitochondrial dysfunction and multi-organ adverse effects. Mitochondrial impairments (mitochondriopathies) are associated with severe pathologies including but not restricted to cancers, cardiovascular diseases, and neurodegeneration. However, the type and level of cascading pathologies are highly individual. Consequently, patient stratification, risk assessment, and mitigating measures are instrumental for cost-effective individualized protection. Therefore, the paradigm shift from reactive to predictive, preventive, and personalized medicine (3PM) is unavoidable in advanced healthcare. Flavonoids demonstrate evident antioxidant and scavenging activity are of great therapeutic utility against mitochondrial damage and cascading pathologies. In the context of 3PM, this review focuses on preclinical and clinical research data evaluating the efficacy of flavonoids as a potent protector against mitochondriopathies and associated pathologies.

Metabolic Anti-Cancer Effects of Melatonin: Clinically Relevant Prospects

Metabolic reprogramming characterized by alterations in nutrient uptake and critical molecular pathways associated with cancer cell metabolism represents a fundamental process of malignant transformation. Melatonin (N-acetyl-5-methoxytryptamine) is a hormone secreted by the pineal gland. Melatonin primarily regulates circadian rhythms but also exerts anti-inflammatory, anti-depressant, antioxidant and anti-tumor activities. Concerning cancer metabolism, melatonin displays significant anticancer effects via the regulation of key components of aerobic glycolysis, gluconeogenesis, the pentose phosphate pathway (PPP) and lipid metabolism. Melatonin treatment affects glucose transporter (GLUT) expression, glucose-6-phosphate dehydrogenase (G6PDH) activity, lactate production and other metabolic contributors. Moreover, melatonin modulates critical players in cancer development, such as HIF-1 and p53. Taken together, melatonin has notable anti-cancer effects at malignancy initiation, progression and metastasing. Further investigations of melatonin impacts relevant for cancer metabolism are expected to create innovative approaches supportive for the effective prevention and targeted therapy of cancers.

Flavonoids as an effective sensitizer for anti-cancer therapy: insights into multi-faceted mechanisms and applicability towards individualized patient profiles

Cost-efficacy of currently applied treatments is an issue in overall cancer management challenging healthcare and causing tremendous economic burden to societies around the world. Consequently, complex treatment models presenting concepts of predictive diagnostics followed by targeted prevention and treatments tailored to the personal patient profiles earn global appreciation as benefiting the patient, healthcare economy, and the society at large. In this context, application of flavonoids as a spectrum of compounds and their nano-technologically created derivatives is extensively under consideration, due to their multi-faceted anti-cancer effects applicable to the overall cost-effective cancer management, primary, secondary, and even tertiary prevention. This article analyzes most recently updated data focused on the potent capacity of flavonoids to promote anti-cancer therapeutic effects and interprets all the collected research achievements in the frame-work of predictive, preventive, and personalized (3P) medicine. Main pillars considered are: - Predictable anti-neoplastic, immune-modulating, drug-sensitizing effects; - Targeted molecular pathways to improve therapeutic outcomes by increasing sensitivity of cancer cells and reversing their resistance towards currently applied therapeutic modalities.

Flavonoids Targeting HIF-1: Implications on Cancer Metabolism

Tumor hypoxia is described as an oxygen deprivation in malignant tissue. The hypoxic condition is a consequence of an imbalance between rapidly proliferating cells and a vascularization that leads to lower oxygen levels in tumors. Hypoxia-inducible factor 1 (HIF-1) is an essential transcription factor contributing to the regulation of hypoxia-associated genes. Some of these genes modulate molecular cascades associated with the Warburg effect and its accompanying pathways and, therefore, represent promising targets for cancer treatment. Current progress in the development of therapeutic approaches brings several promising inhibitors of HIF-1. Flavonoids, widely occurring in various plants, exert a broad spectrum of beneficial effects on human health, and are potentially powerful therapeutic tools against cancer. Recent evidences identified numerous natural flavonoids and their derivatives as inhibitors of HIF-1, associated with the regulation of critical glycolytic components in cancer cells, including pyruvate kinase M2(PKM2), lactate dehydrogenase (LDHA), glucose transporters (GLUTs), hexokinase II (HKII), phosphofructokinase-1 (PFK-1), and pyruvate dehydrogenase kinase (PDK). Here, we discuss the results of most recent studies evaluating the impact of flavonoids on HIF-1 accompanied by the regulation of critical enzymes contributing to the Warburg phenotype. Besides, flavonoid effects on glucose metabolism via regulation of HIF-1 activity represent a promising avenue in cancer-related research. At the same time, only more-in depth investigations can further elucidate the mechanistic and clinical connections between HIF-1 and cancer metabolism.

Rhus coriaria L. (Sumac) Demonstrates Oncostatic Activity in the Therapeutic and Preventive Model of Breast Carcinoma

Comprehensive scientific data provide evidence that isolated phytochemicals or whole plant foods may beneficially modify carcinogenesis. The aim of this study was to evaluate the oncostatic activities of Rhus coriaria L. (sumac) using animal models (rat and mouse), and cell lines of breast carcinoma. R. coriaria (as a powder) was administered through the diet at two concentrations (low dose: 0.1% (w/w) and high dose: 1 % (w/w)) for the duration of the experiment in a syngeneic 4T1 mouse and chemically-induced rat mammary carcinoma models. After autopsy, histopathological and molecular analyses of tumor samples in rodents were performed. Moreover, in vitro analyses using MCF-7 and MDA-MB-231 cells were conducted. The dominant metabolites present in tested R. coriaria methanolic extract were glycosides of gallic acid (possible gallotannins). In the mouse model, R. coriaria at a higher dose (1%) significantly decreased tumor volume by 27% when compared to controls. In addition, treated tumors showed significant dose-dependent decrease in mitotic activity index by 36.5% and 51% in comparison with the control group. In the chemoprevention study using rats, R. coriaria at a higher dose significantly reduced the tumor incidence by 20% and in lower dose non-significantly reduced tumor frequency by 29% when compared to controls. Evaluations of the mechanism of oncostatic action using valid clinical markers demonstrated several positive alterations in rat tumor cells after the treatment with R. coriaria. In this regard, histopathological analysis of treated tumor specimens showed robust dose-dependent decrease in the ratio of high-/low-grade carcinomas by 66% and 73% compared to controls. In treated rat carcinomas, we found significant caspase-3, Bax, and Bax/Bcl-2 expression increases; on the other side, a significant down-regulation of Bcl-2, Ki67, CD24, ALDH1, and EpCam expressions and MDA levels. When compared to control specimens, evaluation of epigenetic alterations in rat tumor cells in vivo showed significant dose-dependent decrease in lysine methylation status of H3K4m3 and H3K9m3 and dose-dependent increase in lysine acetylation in H4K16ac levels (H4K20m3 was not changed) in treated groups. However, only in lower dose of sumac were significant decreases in the expression of oncogenic miR210 and increase of tumor-suppressive miR145 (miR21, miR22, and miR155 were not changed) observed. Finally, only in lower sumac dose, significant decreases in methylation status of three out of five gene promoters-ATM, PTEN, and TIMP3 (PITX2 and RASSF1 promoters were not changed). In vitro evaluations using methanolic extract of R. coriaria showed significant anticancer efficacy in MCF-7 and MDA-MB-231 cells (using Resazurin, cell cycle, annexin V/PI, caspase-3/7, Bcl-2, PARP, and mitochondrial membrane potential analyses). In conclusion, sumac demonstrated significant oncostatic activities in rodent models of breast carcinoma that were validated by mechanistic studies in vivo and in vitro.

Implications of flavonoids as potential modulators of cancer neovascularity

PURPOSE

The formation of new blood vessels from previous ones, angiogenesis, is critical in tissue repair, expansion or remodeling in physiological processes and in various pathologies including cancer. Despite that, the development of anti-angiogenic drugs has great potential as the treatment of cancer faces many problems such as development of the resistance to treatment or an improperly selected therapy approach. An evaluation of predictive markers in personalized medicine could significantly improve treatment outcomes in many patients.

METHODS

This comprehensive review emphasizes the anticancer potential of flavonoids mediated by their anti-angiogenic efficacy evaluated in current preclinical and clinical cancer research.

RESULTS AND CONCLUSION

Flavonoids are important groups of phytochemicals present in common diet. Flavonoids show significant anticancer effects. The anti-angiogenic effects of flavonoids are currently a widely discussed topic of preclinical cancer research. Flavonoids are able to regulate the process of tumor angiogenesis through modulation of signaling molecules such as VEGF, MMPs, ILs, HIF or others. However, the evaluation of the anti-angiogenic potential of flavonoids within the clinical studies is not frequently discussed and is still of significant scientific interest.

An ultrasound probe array for a high-pressure, high-temperature solid medium deformation apparatus

Inelastic deformation of minerals and rocks is associated with activation of various defects such as fractures, twins, and dislocations. Active and passive ultrasound probes are potential tools to examine the nature of these defects under a broad range of pressure and temperature conditions. Here, we report on the development of an ultrasound probe array that allows us to monitor deforming samples in a high-pressure, high-temperature solid medium apparatus (a modified Griggs rig). We utilize several broadband miniature piezoelectric sensors that are placed above and below the sample to record acoustic emissions accompanying deformation and determine their locations in 1D. The emissions are recorded at 50 MS/s with a 12 bit resolution. Proper grounding and electric insulation of the sensors, together with optimized power delivery from the heating system, tremendously reduces electromagnetic interference and allows for a background noise level of ≈90 mV at a full range of ±2 V and 60 dB amplification. The system is capable of recording acoustic waves from 80 kHz to 2.5 MHz at sample temperatures up to 1100 °C and confining pressure up to 2.5 GPa.

Genoprotective activities of plant natural substances in cancer and chemopreventive strategies in the context of 3P medicine

Severe durable changes may occur to the DNA structure caused by exogenous and endogenous risk factors initiating the process of carcinogenesis. By evidence, a large portion of malignancies have been demonstrated as being preventable. Moreover, the targeted prevention of cancer onset is possible, due to unique properties of plant bioactive compounds. Although genoprotective effects of phytochemicals have been well documented, there is an evident lack of articles which would systematically present the spectrum of anticancer effects by phytochemicals, plant extracts, and plant-derived diet applicable to stratified patient groups at the level of targeted primary (cancer development) and secondary (cancer progression and metastatic disease) prevention. Consequently, clinical implementation of knowledge accumulated in the area is still highly restricted. To stimulate coherent co-development of the dedicated plant bioactive compound investigation on one hand and comprehensive cancer preventive strategies on the other hand, the current paper highlights and deeply analyses relevant evidence available in the area. Key molecular mechanisms are presented to detail genoprotective and anticancer activities of plants and phytochemicals. Clinical implementation is discussed. Based on the presented evidence, advanced chemopreventive strategies in the context of 3P medicine are considered.

The role of dietary phytochemicals in the carcinogenesis via the modulation of miRNA expression

PURPOSE

Phytochemicals are naturally occurring plant-derived compounds and some of them have the potential to serve as anticancer drugs. Based on recent evidence, aberrantly regulated expression of microRNAs (miRNAs) is closely associated with malignancy. MicroRNAs are characterized as small non-coding RNAs functioning as posttranscriptional regulators of gene expression. Accordingly, miRNAs regulate various target genes, some of which are involved in the process of carcinogenesis.

RESULTS

This comprehensive review emphasizes the anticancer potential of phytochemicals, either isolated or in combination, mediated by miRNAs. The ability to modulate the expression of miRNAs demonstrates their importance as regulators of tumorigenesis. Phytochemicals as anticancer agents targeting miRNAs are widely studied in preclinical in vitro and in vivo research. Unfortunately, their anticancer efficacy in targeting miRNAs is less investigated in clinical research.

CONCLUSIONS

Significant anticancer properties of phytochemicals as regulators of miRNA expression have been proven, but more studies investigating their clinical relevance are needed.

Plant natural modulators in breast cancer prevention: status quo and future perspectives reinforced by predictive, preventive, and personalized medical approach

In contrast to the genetic component in mammary carcinogenesis, epigenetic alterations are particularly important for the development of sporadic breast cancer (BC) comprising over 90% of all BC cases worldwide. Most of the DNA methylation processes are physiological and essential for human cellular and tissue homeostasis, playing an important role in a number of key mechanisms. However, if dysregulated, DNA methylation contributes to pathological processes such as cancer development and progression. A global hypomethylation of oncogenes and hypermethylation of tumor-suppressor genes are characteristic of most cancer types. Moreover, histone chemical modifications and non-coding RNA-associated multi-gene controls are considered as the key epigenetic mechanisms governing the cellular homeostasis and differentiation states. A number of studies demonstrate dietary plant products as actively affecting the development and progression of cancer. "Nutri-epigenetics" focuses on the influence of dietary agents on epigenetic mechanisms. This approach has gained considerable attention; since in contrast to genetic alterations, epigenetic modifications are reversible affect early carcinogenesis. Currently, there is an evident lack of papers dedicated to the phytochemicals/plant extracts as complex epigenetic modulators, specifically in BC. Our paper highlights the role of plant natural compounds in targeting epigenetic alterations associated with BC development, progression, as well as its potential chemoprevention in the context of preventive medicine. Comprehensive measures are stated with a great potential to advance the overall BC management in favor of predictive, preventive, and personalized medical services and can be considered as "proof-of principle" model, for their potential application to other multifactorial diseases.

Dietary phytochemicals in breast cancer research: anticancer effects and potential utility for effective chemoprevention

Cancerous tissue transformation developing usually over years or even decades of life is a highly complex process involving strong stressors damaging DNA, chronic inflammation, comprehensive interaction between relevant molecular pathways, and cellular cross-talk within the neighboring tissues. Only the minor part of all cancer cases are caused by inborn predisposition; the absolute majority carry a sporadic character based on modifiable risk factors which play a central role in cancer prevention. Amongst most promising candidates for dietary supplements are bioactive phytochemicals demonstrating strong anticancer effects. Abundant evidence has been collected for beneficial effects of flavonoids, carotenoids, phenolic acids, and organosulfur compounds affecting a number of cancer-related pathways. Phytochemicals may positively affect processes of cell signaling, cell cycle regulation, oxidative stress response, and inflammation. They can modulate non-coding RNAs, upregulate tumor suppressive miRNAs, and downregulate oncogenic miRNAs that synergically inhibits cancer cell growth and cancer stem cell self-renewal. Potential clinical utility of the phytochemicals is discussed providing examples for chemoprevention against and therapy for human breast cancer. Expert recommendations are provided in the context of preventive medicine.

Antineoplastic effects of clove buds (Syzygium aromaticum L.) in the model of breast carcinoma

It is supposed that plant functional foods, rich in phytochemicals, may potentially have preventive effects in carcinogenesis. In this study, the anticancer effects of cloves in the in vivo and in vitro mammary carcinoma model were assessed. Dried flower buds of cloves (CLOs) were used at two concentrations of 0.1% and 1% through diet during 13 weeks after the application of chemocarcinogen. After autopsy, histopathological and immunohistochemical analyses of rat mammary carcinomas were performed. Moreover, in vitro evaluation using MCF‐7 cells was carried out. Dietary administered CLO caused the dose‐dependent decrease in tumour frequency by 47.5% and 58.5% when compared to control. Analysis of carcinoma cells in animals showed bcl‐2, Ki67, VEGFA, CD24 and CD44 expression decrease and Bax, caspase‐3 and ALDH1 expression increase after high‐dose CLO administration. MDA levels were substantially decreased in rat carcinomas in both CLO groups. The evaluation of histone modifications revealed increase in lysine trimethylations and acetylations (H4K20me3, H4K16ac) in carcinomas after CLO administration. TIMP3 promoter methylation levels of CpG3, CpG4, CpG5 islands were altered in treated cancer cells. An increase in total RASSF1A promoter methylation (three CpG sites) in CLO 1 group was found. In vitro studies showed antiproliferative and pro‐apoptotic effects of CLO extract in MCF‐7 cells (analyses of cytotoxicity, Brdu, cell cycle, annexin V/PI, caspase‐7, Bcl‐2 and mitochondrial membrane potential). This study showed a significant anticancer effect of clove buds in the mammary carcinoma model in vivo and in vitro.

Angiomodulators in cancer therapy: New perspectives

The formation of new blood vessels plays a crucial for the development and progression of pathophysiological changes associated with a variety of disorders, including carcinogenesis. Angiogenesis inhibitors (anti-angiogenics) are an important part of treatment for some types of cancer. Some natural products isolated from marine invertebrates have revealed antiangiogenic activities, which are diverse in structure and mechanisms of action. Many preclinical studies have generated new models for further modification and optimization of anti-angiogenic substances, and new information for mechanistic studies and new anti-cancer drug candidates for clinical practice. Moreover, in the last decade it has become apparent that galectins are important regulators of tumor angiogenesis, as well as microRNA. MicroRNAs have been validated to modulate endothelial cell migration or endothelial tube organization. In the present review we summarize the current knowledge regarding the role of marine-derived natural products, galectins and microRNAs in tumor angiogenesis.

News in Pathogenesis of Chronic Venous Insufficiency

This review article is concentrating on the news in the pathophysiology of chronic venous insufficiency (CVD). Despite ongoing progress in understanding the molecular aspects of CVD the exact mechanism of its development remains unclear. Many different factors may play role in the pathogenesis of CVD, including changes in hydrostatic pressure, valvular incompetence, increased capillary permeability, endothelial dysfunction, activation of leukocytes, deep venous obstruction, capillary microthrombosis, ineffective function of calf muscle pump, biochemical and structural changes in the vessel wall, extracellular matrix alteration, and several other mechanisms. A better understanding of the pathophysiology is an important step in the finding of new potential treatment.

Fibroepithelioma of Pinkus

Basal cell carcinoma (BCC) is recently the most common cancer in humans characterized by several histopathological subtypes. Fibroepithelioma of Pinkus (FEP) is traditionally classified as a very rare variant of BCC, however, it manifests clinical and morphological differences that distinguish it from most other types BCCs. This study was performed to evaluate the incidence of FEP and clinical-pathological characteristics of patients diagnosed with this tumor. Four cases of primary FEP (3 females, 1 male, mean age 53.4 y) were analyzed retrospectively. The prevalence of FEP was 0.7 % of all diagnosed BCCs. Topographically, tumors were localized on the right brachium, right gluteal region, left mesogastrium, and right side of the abdomen. Histological examination showed typical anastomosing cords of basaloid cells extending from the overlying epidermis into the loose fibrous stroma in the dermis. Mitotic activity or significant cellular atypia, as well as sign of solar dermatosis were absent. Mean horizontal and vertical diameter of the lesions were 7.7 and 2.8 mm, retrospectively. We did not observe infiltration of deeper skin structures. All lesions were removed completely and classified as pathological stage pT1. Three cases manifested typical picture of a "pure" FEP, one lesion had partially a feature of nodular type BCC, too. Although FEP is conventionally considered as indolent BCC variant with a favorable clinical outcome, recent evidences also favors its classification as a form of trichoblastoma. This is appropriate example how some types of cutaneous tumors can overlap in terms of dignity and clinical-morphological characteristics. This should be taken into account in differential diagnosis and in predicting of biological behaviour of the individual tumors of the skin (Tab. 2, Fig. 3, Ref. 26).

Comparision of histological types of primary and subsequent relapsing basal cell carcinomas of the skin

BACKGROUND

Basal cell carcinoma (BCC) recurrences are relatively frequent event in a routine dermatologic practice. One of the most important factor which impacts risk of their development is a histomorphological appearance of tumor.

DESIGN

The purpose of our study was to compare histological types of primary and corresponding relapsing BCCs of the skin.

MATERIAL AND METHODS

The study included 36 cases of BCC recurrences from 34 patients, 17 women and 17 men. The patients ranged in age from 32 to 97 years, with a mean age of 67.1 years at the time of (the first) recurrence.

RESULTS

Both tumor groups generally exhibited the same proportion of indolent and aggressive histological phenotype. In 21 cases (58.4%), we found an identical histological BCC type in primary and subsequent relapsing lesion. In 3 cases (8.3%), primary lesion showed indolent histological features without aggressive--growth component, while recurrent tumor already manifested it. Conversely, in next 3 cases (8.3%) primary tumor exhibited focal infiltrative-growth features and corresponding relapsing lesion did not. Of the remaining 9 cases (25%), histomorphological phenotype was not identical, but it showed the same prognostic histological tumor variant.

CONCLUSION

Based on the results of our study it can be assumed that a BCC recurrence is a dynamic histogenetic process, during which the phenotypic transformation and the changes in histomorphological picture of lesions occur, probably as a result of the interactions between cancer cells and re-modulated surrounding stroma.

Congenital polycystic kidney disease in one of the twins

Cystic renal disorders generally comprise a heterogeneous group of conditions. The most common genetic form is a polycystic kidney disease. This nosologic entity can be inherited as either an autosomal recessive or autosomal dominant trait. Among all cystic renal disorders, autosomal recessive polycystic kidney disease is the most frequent heritable disease manifesting in infancy and childhood and is among those that come to clinical attention early. The characteristic pathologic changes occur in the kidneys and the liver, however, several other organ systems can be affected secondarily. Both kidneys are enlarged because of multiple progressive cystic dilatation of the renal tubules that results to renal failure. The liver is characterized by periportal fibrosis with bile ducts abnormalities. The renal and hepatic manifestations are more or less inversely proportional in individual patients. Therefore, the morphological features and clinical presentation of this disorder can vary substantially. Moreover, there is also a great variability in the severity and manifestations even between individuals from the same family who carry the identical mutations. The authors present a case report of a fatal clinical course of the perinatal congenital polycystic kidney disease in one of the twins (Fig. 4, Ref. 19).

Celecoxib and melatonin in prevention of female rat mammary carcinogenesis

The present experiment aims to evaluate tumor suppressive effects of a selective inhibitor of cyclooxygenase-2 (COX-2) celecoxib (Celebrex, Pfizer) administered alone and in combination with melatonin in the prevention of N-methyl-N-nitrosourea (NMU)-induced mammary carcinogenesis in Sprague-Dawley female rats. Celecoxib was administered daily at a concentration of 1.666 g/kg diet to two groups during 20 weeks (starting a week before first NMU application). A combination of celecoxib and melatonin applied in drinking water (20 microg/ml drinking water), daily from 15:00 to 08:00 hours was administered to the second group. The anticarcinogenic effects of chemopreventive drugs were compared with control (NMU) animals. Celecoxib administration decreased mammary tumor incidence (by 24%), while combination of celecoxib and melatonin decreased tumor incidence even more significantly (-30%). Significant decrease in tumor frequency per group was recorded in both groups with chemoprevention: celecoxib alone (-54%) and combination of celecoxib and melatonin (-64%). Celecoxib significantly influenced tumor frequency per animal in the group with combination of both protective substances (-52%). Celecoxib administration resulted in prolonged latency by 3%, and by 13% in the group with combination of both protective substances. These results confirm preventive effects of celecoxib in induced rat mammary carcinogenesis. The administration of isolated MEL had only lesser effect, but in the combination with CELE revealed some potentiating influence in mammary carcinogenesis inhibition. The present study is the first to prove efficacy of the above-mentioned celecoxib and melatonin intake. Our results point to the need for a deeper analysis of coxib efficacy in human carcinogenesis.

Expression pattern of anti-apoptotic protein survivin in dysplastic nevi

The anti-apoptotic protein survivin was detected in a panel of 27 dysplastic nevi. From each representative paraffin block 4 mm sections were cut and stained with anti-survivin antibody (DAKO, Clone 12C4). In each section, the labeling intensity, the subcellular location of survivin antigen, the percentage of labeled cells and the degree of dysplasia were assessed. Survivin was present in 23 out of 27 cases (85.2%), but absent in 4/27 cases (14.8%). Positive staining was confined to the cytoplasm (C) of nevus cells only in 18 cases (66.7%), while cytoplasmic as well as nuclear positivity (NC) was found in 5 cases (18.5%). In no case solely nuclear staining could be seen. Furthermore, in 4 out of 5 cases (80%) with NC staining, severe dysplasia was found. Our data point at usefulness of survivin staining, otherwise rarely performed in dysplastic nevi. We confirm the importance of nuclear location of the survivin antigen, which may be helpful for assessing the possible progression to melanoma.

KEYWORDS

survivin, immunohistochemistry, nevi, dysplasia, melanoma.

Cough reflex sensitivity testing in in seasonal allergic rhinitis patients and healthy volunteers

Dysfunction of upper and lower airways frequently coexists, and they appear to share key elements of pathogenesis. The interrelationship between upper and lower airway manifestations of allergy remains still incompletely investigated. Little is known about the critical factors that determine airway afferent nerve endings reactivity (cough sensitivity) in patients with allergic rhinitis. Subclinical inflammatory changes within the lower airways and/or chronic upper airway cough syndrome (previously referred to as postnasal drip syndrome) are probably responsible for this effect. The aim of this study was to evaluate capsaicin cough sensitivity in pollen sensitive patients with seasonal allergic rhinitis without treatment out of a grass pollen season time using the European Respiratory Society (ERS) guidelines on the assessment of cough. Cough sensitivity was defined as the lowest capsaicin concentration which evoked two (C2) or five (C5) coughs. Capsaicin aerosol in doubling concentrations (from 0.49 to 1000 micromol/l) was inhaled by a single breath method (KoKo DigiDoser; nSpire heath Inc, Louisville, CO), modified by the addition of an inspiratory flow regulator valve (RIFR; nSpire heath Inc, Louisville, CO). The seasonal rhinitis subjects (5M, 7F; mean age 23 yr) had not been complaining primarily about coughing. Their pulmonary function was within normal range. Concentrations of capsaicin causing two (C2) and five coughs (C5) were reported. Volunteers' (5M, 7F, mean age 23 yr) cough sensitivity (geometric mean and 95 % CI) for C2 was 16.5 (4.1-67.0) micromol/l vs. allergic rhinitis patients' C2 3.5 (1.9 - 6.4) (P= 0.018). Volunteers' C5 was 132.4 (41.3 - 424.5) micromol/l vs. allergic rhinitis patients' C5 13.1 (6.0 - 28.6) micromol/l (P= 0.013). We conclude that airway afferent nerve endings reactivity in pollen sensitive subjects suffering from seasonal allergic rhinitis was significantly increased out of pollen season compared with healthy volunteers.

Influences of stroma-derived growth factors on the cytokine expression pattern of human breast cancer cell lines

Tumor growth and local invasion are greatly dependent on the malignant potential of a tumor cell, but are also significantly modulated by a variety of local factors. These factors comprise cytokines, growth factors and extracellular matrix proteins (ECM), which act through a complex system of auto-, para- and juxtacrine interactions. Some factors are produced by the malignant cell itself, others are expressed by adjacent tumor stroma, migrated inflammatory cells, or resident macrophages. We have investigated the influences of cytokines and growth factors known to be expressed by tumor stroma on the cytokine expression pattern of three human breast cancer cell lines of different malignant potential. MCF-7, T47D and MDA-MB-231 were incubated with human recombinant TNF-alpha, IGF-I, IGF-II, bFGF, HGF or G-CSF and the pattern of tumor-cell-derived TGF-beta1, bFGF, IL-1alpha and VEGF was analyzed. Among the three cell lines used we observed a heterogenous response to stromal cytokines by measuring above mentioned factors in the cell culture's supernatants, but no clear correlation between malignant potential and cytokine expression pattern seemed obvious. We hypothesize that local growth factors may have a significant modulatory effect on malignant behavior in vivo. We conclude that this effect might depend on individual responses and on the differentiation state of tumor cells.

Characterization of api g 1.0201, a new member of the Api g 1 family of celery allergens

BACKGROUND

The association of pollinosis with allergy to plant foods occurs in up to 70% of tree pollen-allergic patients. In recent years, some of the relevant cross-reacting proteins have been characterized at the molecular and immunological level. Api g 1 has been identified as the celery homologue of the major birch pollen allergen, Bet v 1. Although a number of Bet v 1 isoforms have been characterized from birch pollen, little is known about isoforms of food allergens and their allergenic features.

METHODS

Api g 1.0201, an isoform of Api g 1, was isolated from a cDNA library, cloned and sequenced. The cDNA was expressed in Escherichia coli and the purified recombinant protein was tested in immunoblots.

RESULTS

Api g 1.0201 displays 72% sequence similarity to the previously identified Api g 1.0101 and consists of 159 amino acid residues. The sequence of Api g 1.0201 has five additional amino acid residues at the carboxy-terminus as compared to Api g 1.0101. Purified recombinant Api g 1.0201 is recognized by IgE from the sera of celery-allergic patients, as well as by the murine monoclonal anti-Bet v 1 antibody. In general, this isoform displays a weaker IgE-binding capacity than Api g 1.0101, as concluded from immunoblotting experiments. Results from inhibition assays revealed that IgE-binding to Api g 1.0201 is only slightly reduced by preincubation with either purified recombinant Api g 1.0101 or purified recombinant Bet v 1a. Total inhibition was only achieved when using purified natural Bet v 1.

CONCLUSIONS

At present, little is known about the IgE-binding capacity of isoforms of Bet v 1 homologues of food allergens. Identification and characterization of such isoforms may help to contribute to a better understanding of food allergy and the observed cross-reactivity to pollen allergy.

Multiple cutaneous metastases as the first sign of lung cancer in a patient with well-differentiated papillary transitional cell carcinoma of the urinary bladder

A case of multiple, cutaneous metastases as the first sign of lung cancer in a patient with well-differentiated, papillary, transitional cell carcinoma of the urinary bladder is presented. In the left clavicular region were two, sharply demarcated, dark red tumors measuring 3 and 2 cm in diameter with a history of rapid growth and intermittent spontaneous bleeding. Thorough examination of the patient revealed 16 additional skin lesions, which were dark red macules and papules, 2-3 mm in diameter, situated on the left side of the chest. The skin biopsy material (tumors, macular and papular lesions) was studied using histological and immunohistochemical techniques and showed intact epidermis and massive dermal and subcutaneous metastatic involvement by a small cell carcinoma with neuroendocrine differentiation most likely originating in the lung.

Phaeohyphomycosis due to Alternaria spp. and Phaeosclera dematioides: a histopathological study

A case of phaeohyphomycosis caused by strains of both Alternaria spp. and Phaeosclera dematioides is presented. The biopsy material was studied using histological, immunohistochemical and transmission electron microscopy techniques. The agent's dematiaceous mycelia are composed of thick-walled hyphae, branched and unbranched, with terminal vesicular formations. All the described structures occur alone or in chains within multinuclear giant foreign body-type cells or invading an abscess. Also present are budding forms. Immunostaining of histiocytic inflammatory cells in either. diffuse or granulomatous infiltrates revealed cytoplasmic positivity for lysozyme and Ki-MIP antibody. The lymphocytic infiltrates of the upper corium show predominantly small T lymphocytes (CD3 and CD45RO positive) and absence of CD20-positive B cells. Plasma cells occurring within the infiltrates of the deeper parts show polyclonal expression of both Ig light chains.

Serum-soluble CD4 as clinical and immunological marker in patients with dilated cardiomyopathy

Serological markers of cell-mediated immunity, i.e., soluble CD4, soluble interleukin-2 (Il-2) receptor and beta 2-microglobulin, were determined in 60 patients with dilated cardiomyopathy. Compared with normal healthy donors (n = 30) and controls who had coronary artery disease with preserved left ventricular function (n = 20), significantly increased levels associated with the New York Heart Association functional classes have been found in the cardiomyopathy patients, irrespectively of the etiology. Out of the immunological variables tested, serum-soluble CD4 most closely reflected the clinical and hemodynamic stage, predicted the presence of lymphocytic aggregates in the myocardium and correlated with the CD4/CD8 ratios of endomyocardial lymphocytes (r = 0.6, P < 0.05). Conversely, focal mononuclear infiltration of the myocardium was associated with significantly elevated CD4/CD8 ratios (2.1 +/- 0.6 vs. 1.3 +/- 0.2, P < 0.05), higher total numbers and percentages of endomyocardial lymphocytes expressing the pan T-markers CD2 and CD3, more CD45RO/UCHL1-positive cells and more CD4-positive T-helper cells, compared with non-reactive cases the lymphocytes of which were scattered throughout the myocardium. In conclusion, in a subset of cardiomyopathy patients lymphocytic clusters in the myocardium indicated an enhanced cellular immune response predominantly mediated by CD4-positive T-helper lymphocytes with active memory function. This immunopathological condition in the heart can be monitored by serum-soluble CD4.