Cancer invasion and metastasis: interacting ecosystems

Molecular mechanism of bone metastasis in breast cancer

Bone metastasis is a debilitating complication that frequently occurs in the advanced stages of breast cancer. However, the underlying molecular and cellular mechanisms of the bone metastasis remain unclear. Here, we elucidate how bone metastasis arises from tumor cells that detach from the primary lesions and infiltrate into the surrounding tissue, as well as how these cells disseminate to distant sites. Specifically, we elaborate how tumor cells preferentially grow within the bone micro-environment and interact with bone cells to facilitate bone destruction, characterized as osteoclastic bone metastasis, as well as new bone matrix deposition, characterized as osteoblastic bone metastasis. We also updated the current understanding of the molecular mechanisms underlying bone metastasis and reasons for relapse in breast cancer, and also opportunities of developing novel diagnostic approaches and treatment.

Transforming Cancer Treatment with Nanotechnology: The Role of Berberine as a Star Natural Compound

Berberine (BBR), recognized as an oncotherapeutic phytochemical, exhibits its anti-cancer properties via multiple molecular pathways. However, its clinical application is hindered by suboptimal tumor accumulation, rapid systemic elimination, and diminished bioactive concentration owing to extensive metabolic degradation. To circumvent these limitations, the strategic employment of nanocarriers and other drugs in combination with BBR is emerging as a focus to potentiate its anti-cancer efficacy. This review introduced the expansive spectrum of BBR's anti-cancer activities, BBR and other drugs co-loaded nanocarriers for anti-cancer treatments, and evaluated the synergistic augmentation of these amalgamated modalities. The aim is to provide an overview of BBR for cancer treatment based on nano-delivery. Berberine (BBR), recognized as an oncotherapeutic phytochemical, exhibits its anti-cancer properties via multiple molecular pathways. However, its clinical application is hindered by suboptimal tumor accumulation, rapid systemic elimination, and diminished bioactive concentration owing to extensive metabolic degradation. To circumvent these limitations, the strategic employment of nanocarriers and other drugs in combination with BBR is emerging as a focus to potentiate its anti-cancer efficacy. Nano-delivery systems increase drug concentration at the tumor site by improving pharmacological activity and tissue distribution, enhancing drug bioavailability. Organic nanocarriers have advantages for berberine delivery including biocompatibility, encapsulation, and controlled release of the drug. While the advantages of inorganic nanocarriers for berberine delivery mainly lie in their efficient loading ability of the drug and their slow release ability of the drug. This review introduced the expansive spectrum of BBR's anti-cancer activities, BBR and other drugs co-loaded nanocarriers for anti-cancer treatments, and evaluated the synergistic augmentation of these amalgamated modalities. The aim is to provide an overview of BBR for cancer treatment based on nano-delivery.

The uncertainties and certainties of gene transcription in a human tumor cell

Previously we have identified that the expression number and levels of oncogenes and antioncogenes are highly positively or negatively associated with major cellular progress in a cancer cell. However, we have not defined any cellular potentials of a human tumor cell at the level of the overall gene expression. Here, we counted the overall number of expression genes and overall counts of mRNA in depth and revealed that the expression levels of mRNA were directly associated with the expression number of genes in a human tumor cell. Gene expression networks revealed steady states of tricarboxylic acid (TCA) cycle and ATP production, differentiation potentials that might be disturbed and blocked by uncertain gene expressing networks, and potential capabilities to undergo epithelial-mesenchymal transition (EMT), neurogenesis, angiogenesis, inflammatory response, immune evasion, and metastasis in a human tumor cell. Our analysis identifies unpredictable gene expression characteristics in human tumor cells. The results might profoundly influence mechanisms how a human tumor cell generates and undergoes its progresses.

Downregulated BIRC5 inhibits proliferation and metastasis of melanoma through the β-catenin/HIF-1α/VEGF/MMPs pathway

PURPOSE

Melanoma is a malignant skin tumor caused by melanocytes and associated with high mortality rates. This study aims to investigate the specific mechanism of ZWZ-3 in melanoma proliferation and metastasis.

METHODS

RNA sequencing was performed to identify the effect of ZWZ-3 on gene expression. siRNA was used to inhibit BIRC5 gene expression in the B16F10 cell line. A zebrafish tumor model was used to assess the therapeutic effect of ZWZ-3 in vivo. Mechanistic insights into the inhibition of tumor metastasis by ZWZ-3 were obtained through analysis of tumor tissue sections in mice.

RESULTS

Our findings demonstrated that ZWZ-3 suppressed melanoma cell proliferation and migration. We performed RNA sequencing in melanoma cells after the treatment with ZWZ-3 and found that Birc5, which is closely associated with tumor metastasis, was significantly down-regulated. Bioinformatics analysis and the immuno-histochemical results of tissue chips for melanoma further confirmed the high expression of BIRC5 in melanoma and its effect on disease progression. Moreover, Birc5 knock-down significantly inhibited melanoma cell proliferation and metastasis, which was correlated with the β-catenin/HIF-1α/VEGF/MMPs pathway. Additionally, ZWZ-3 significantly inhibited tumor growth in the zebrafish tumor model without any evident side effects. Histological and immuno-histochemical analyses revealed that ZWZ-3 inhibited tumor cell metastasis by down-regulating HIF-1α, VEGF, and MMP9.

CONCLUSION

Our findings revealed that ZWZ-3 could downregulate BIRC5 and inhibit melanoma proliferation and metastasis through the β-catenin/HIF-1α/VEGF/MMPs pathway. Therefore, BIRC5 represents a promising therapeutic target for the treatment of melanoma.

The underexplored links between cancer and the internal body climate: Implications for cancer prevention and treatment

In order to effectively manage and cure cancer we should move beyond the general view of cancer as a random process of genetic alterations leading to uncontrolled cell proliferation or simply a predictable evolutionary process involving selection for traits that increase cell fitness. In our view, cancer is a systemic disease that involves multiple interactions not only among cells within tumors or between tumors and surrounding tissues but also with the entire organism and its internal "milieu". We define the internal body climate as an emergent property resulting from spatial and temporal interactions among internal components themselves and with the external environment. The body climate itself can either prevent, promote or support cancer initiation and progression (top-down effect; i.e., body climate-induced effects on cancer), as well as be perturbed by cancer (bottom-up effect; i.e., cancer-induced body climate changes) to further favor cancer progression and spread. This positive feedback loop can move the system towards a "cancerized" organism and ultimately results in its demise. In our view, cancer not only affects the entire system; it is a reflection of an imbalance of the entire system. This model provides an integrated framework to study all aspects of cancer as a systemic disease, and also highlights unexplored links that can be altered to both prevent body climate changes that favor cancer initiation, progression and dissemination as well as manipulate or restore the body internal climate to hinder the success of cancer inception, progression and metastasis or improve therapy outcomes. To do so, we need to (i) identify cancer-relevant factors that affect specific climate components, (ii) develop 'body climate biomarkers', (iii) define 'body climate scores', and (iv) develop strategies to prevent climate changes, stop or slow the changes, or even revert the changes (climate restoration).

Mechanistic insights expatiating the biological role and regulatory implications of estrogen and HER2 in breast cancer metastasis

Breast cancer (BCa) has become the leading cause of death in women worldwide. Irrespective of advancement in cancer treatments, e.g., surgery, radiation, chemotherapy, hormonal therapy, immunotherapy, and targeted therapy, recurrence leading to metastasis poses the greatest threat in BCa management. BCa receptors estrogen (ER), progesterone (PR), and human epidermal growth factor receptor-2 (HER2) hold significant reputations as prognostic and predictive biomarkers in therapeutic decision-making. Under normal physiological conditions, these receptors modulate critical biological functions, e.g., cell migration, proliferation, and apoptosis events, etc. However, aberrant expression causes deviations, triggering signaling course to adapt permanent switching "ON" mode. The later events induce rapid and unrestrained proliferation leading to cancer. As conventional ways of cancer management ultimately lead to resistance; therefore, recently targeted therapies have been extensively studied to conquer resistance. Targeting various small molecules in downstream signaling has become an area of interest in scientific society. The severity of cancer converts many folds soon after it takes on a migratory approach that eventually commences metastasis. Cancer migration comprises protrusion of cytoplasm at the leading edge of the migration forward-facing, establishing adhesions with the basic cell-matrix, disassembly of the adhesions at the back end of the cell, and actin-myosin fiber contractions to pull the bulk of the cytoplasm forward. On the other hand, metastatic progression comprises a cascade of events, including invasion, migration, and establishment of tumor microenvironment. The progression of BCa from early stage to metastatic development causes remarkable heterogeneity. Interference at any explicit level could hamper the process, and it has thus become an area of interest for scientists. Metastasis is the ultimate cause of spreading tumor cells to invade distant organs. Recently small molecule inhibitors of protein tyrosine kinases, which can cross the blood-brain barrier, have become a center point of research for investigators in developing novel treatment strategies against BCa management.

Biology of Cancer and PET Imaging: Pictorial Review

Development and spread of cancer is a multi-step and complex process which involves number of alterations, interactions and molecular networks. PET imaging is closely related with biology of cancer as it detects the cancer based on biological and pathological changes in tumor cells and tumor microenvironment. In this review article, biology of development and spread of cancer and role of PET imaging in Oncology was summarized and supported with various PET images demonstrating cancer spread patterns.

Identification of CCNB2 as A Potential Non-Invasive Breast Cancer Biomarker in Peripheral Blood Mononuclear Cells Using The Systems Biology Approach

OBJECTIVE

Breast cancer (BC) still remains an imperative clinical issue, despite advances in the diagnosis, prognosis and treatment modalities of this malignancy. Hence, progress has been made to identify non-invasive, high sensitive and specific biomarkers. Since immune system affects development of breast cancer, peripheral blood mononuclear cells (PBMCs) -a subpopulation of immune cells- can be considered as a promising tool in the field of BC biomarker research. In the current study, we initially attempted to use concept of the present shared biomarkers in solid tumors and systemic immune profile and then evaluate correlation of these biomarkers to clinical use in cancer research.

MATERIALS AND METHODS

In this experimental study, available microarray gene expression datasets of BC as well as the related PBMCs were retrieved and downloaded from the Gene Expression Omnibus (GEO) database, followed by analysis using GEO2R along with affylmGUI, a R-based package, to obtain differentially expressed genes (DEGs). Signature genes from 20 types of cancer were also applied to validate DEGs. Quantitative reverse-transcription polymerase chain reaction (qRT-PCR) was carried out to assess mRNA level of CCNB2 in PBMC of the BC patients and healthy subjects.

RESULTS

DEGs analysis for the transcription profile of BC cells and PBMCs showed two shared targets, CCNB2 and PGK1. Validation with systems biology using reweighted 20 types of cancer signature genes revealed that CCNB2 is the only common target in BC and its related PBMCs, which was further validated by qRT-PCR implying a significant increase in the level of CCNB2 in the BC patients.

CONCLUSION

Results of this study demonstrated that PBMCs are affected by BC cells and CCNB2 may be of value as a diagnostic biomarker for breast cancer. However, verification would require future detailed experimental plans.

[E-cadherin expression in tumor emboli in gastric cancer]

OBJECTIVE

To determine the level of E-cadherin expression in tumor emboli, to compare it with expression in a tumor, to determine the dependence of E-cadherin expression in tumor emboli on the clinical and morphological characteristics of gastric cancer.

MATERIAL AND METHODS

We used samples of surgical material from 280 patients with a verified diagnosis of gastric cancer. E-cadherin expression was determined by immunohistochemical method. The results of the reactions were assessed semi-quantitatively and compared with the main clinical and morphological characteristics of gastric cancer (histological type according to the WHO classification 2019, histological type according to the classification of P. Lauren, clinical stage, depth of invasion (T), number of metastases in lymph nodes (N), presence or/absence of distant metastases (M), tumor localization in the stomach).

RESULTS

Among 280 cases of cancer, emboli were detected only in 67 cases, used for further analysis. The rest of the samples were excluded from the analysis, since emboli did not get into the sections during the cutting of immunohistochemical preparations. The expression of E-cadherin in tumor emboli was significantly higher (p<0.001) than in tumor tissue. At the same time, no cases identified where the level of E-cadherin decreased in emboli compared to the tumor. A significant increase in the expression of E-cadherin in tumor emboli compared to the primary tumor was noted for all histological types according to WHO 2019, for intermediate and diffuse types according to the P. Lauren classification (p<0.001). Comparison of expression in emboli and tumors for neoplasms with different depths of invasion (T), different stages and different localizations did not reveal statistically significant differences. An increase in the expression of E-cadherin in emboli compared to tumors was characterized by a higher level of significance in the presence of metastases (N1, N2, N3a, N3b; p<0.001) than in the absence of metastases (N0; p=0.016).

CONCLUSION

The study revealed a statistically significant increase in the expression of E-cadherin in tumor emboli compared to the primary tumor, which is evidence of its important role in maintaining the integrity of emboli and tumor dissemination.

MicroRNA-15b in extracellular vesicles from arsenite-treated macrophages promotes the progression of hepatocellular carcinomas by blocking the LATS1-mediated Hippo pathway

Arsenic, a human carcinogen, causes various human cancers, including those of the skin, lung, and liver. Hepatocellular carcinomas (HCCs), which have high mortality, are common malignancies worldwide. Tumor-associated macrophages (TAMs), which are considered to be similar to M2-polarized macrophages, promote tumor invasion and progression. Small non-coding RNAs (miRNAs) regulate expression of genes involved in progression of various malignancies. Extracellular vesicles (EVs), as mediators of cell communication, pass specific miRNAs directly from TAMs to tumor cells, promoting tumor pathogenesis and metastasis. In HCCs, large tumor suppressor kinase 1 (LATS1), functions as a tumor suppressor. However, the molecular mechanism by which miRNA modulates LATS1 expression in HCCs remains unclear. The results show that exposure to arsenite, increased miR-15b levels and induced M2 polarization of THP-1 cells. Elevated levels of miR-15b were transferred from arsenite-treated-THP-1 (As-THP-1) cells to HCC cells via miR-15b in EVs inhibited activation of the Hippo pathway by targeting LATS1, and was involved in promoting the proliferation, migration, and invasion of HCC cells. In conclusion, miR-15b in EVs from As-THP-1 cells is transferred to HCC cells, in which it targets and downregulates LATS1 expression and promotes the proliferation, migration, and invasion of HCC cells.

Giulio Gabbiani and the discovery of myofibroblasts

Myofibroblasts, specialized fibroblasts expressing the protein alpha-smooth muscle actin, are instrumental in wound contraction during normal wound healing. Tissue shortening is then stabilized by the synthesis of extracellular matrix, collagen in particular. Alpha-smooth muscle actin within myofibroblasts becomes organized in filamentous bundles, called stress fibers, that allow the retractile movement producing wound contraction. During hypertrophic scarring, skin deformations depend on the inappropriate action of these stress fibers that for unknown reasons persist even after the epithelialization of the wound. This historical review article is dedicated to the reconstruction of the discovery of this cell by the Italian scientist Giulio Gabbiani.

Differential expression of E-cadherin and P-cadherin in pT3 prostate cancer: correlation with clinical and pathological features

Cadherins seem to play and important role in prostate cancer (PCa) progression. E-cadherin loss of expression has been associated with poor prognosis; P-cadherin's role is still elusive. Although pT3 PCa is often considered "high-risk cancer," it does not exhibit an uniformly poor prognosis. Herein, we assessed the prognostic value and survival impact of E-cadherin and P-cadherin immunoexpression in pT3 PCa. Radical prostatectomy (RP) specimens from 102 pT3 PCa patients treated between 1991 and 2014 in a single institution were designated for E-cadherin and P-cadherin immunoexpression analysis. A representative block from each specimen was selected for tissue micro-array (TMA) construction, using 3 cores per case. E-cadherin immunoexpression was assessed via a digital image analysis system. For P-cadherin, scoring criteria for HER2 in gastric cancer were used. Clinical records of all patients were reviewed for baseline clinical/pathologic characteristics and follow-up data. E-cadherin-low PCa patients displayed worse disease-specific survival (DSS), although not reaching statistical significance (HR 2.65, 95%CI 0.81-7.88). However, considering the pT3b group only, those with low E-cadherin immunoexpression displayed significantly worse overall-survival (OS) and DSS (HR 3.69, 95%CI 1.18-11.50; HR 5.90, 95%CI 1.40-24.81). No significant differences in survival were found for P-cadherin differential immunoexpression. Furthermore, an association between E-cadherin and P-cadherin immunoexpression (p = 0.019) was found, as among E-cadherin-low PCa, 96.6% were P-cadherin negative. We demonstrated that low E-cadherin immunoexpression discriminates among pT3b PCa patients those with poorer survival and which might benefit from specific therapy. The role of P-cadherin in PCa seems context-dependent deserving further investigation.

Effects of radiation on the metastatic process

Radiotherapy remains one of the corner stones in the treatment of various malignancies and often leads to an improvement in overall survival. Nonetheless, pre-clinical evidence indicates that radiation can entail pro-metastatic effects via multiple pathways. Via direct actions on cancer cells and indirect actions on the tumor microenvironment, radiation has the potential to enhance epithelial-to-mesenchymal transition, invasion, migration, angiogenesis and metastasis. However, the data remains ambiguous and clinical observations that unequivocally prove these findings are lacking. In this review we discuss the pre-clinical and clinical data on the local and systemic effect of irradiation on the metastatic process with an emphasis on the molecular pathways involved.

KiSS1 gene as a novel mediator of TGFβ-mediated cell invasion in triple negative breast cancer

The invasive and metastatic phenotypes of breast cancer correlate with high recurrence rates and poor survival outcomes. Transforming growth factor-β (TGFβ) promotes tumor progression and metastasis in aggressive breast cancer. Here, we identified the kisspeptin KiSS1 as a downstream target of canonical TGFβ/Smad2 pathway in triple negative breast cancer cells. We also found KiSS1 expression to be required for TGFβ-induced cancer cell invasion. Indeed, knockdown expression of KiSS1 blocked TGFβ-mediated cancer cell invasion as well as metalloproteinase (MMP9) expression and activity. Interestingly, Kisspeptin-10 (KP-10), the smallest active form of kisspeptin also stimulates cancer cell invasive behavior through activation of MAPK/Erk pathway. We described a positive feedback loop between KiSS1 and p21 downstream of TGFβ, further contributing to TGFβ-induced cancer cell invasion. Lastly, we explored both the clinical utility of KiSS1 as a lymph node involvement predictive tool and its potential as a therapeutic target. We found KiSS1 high expression to correlate with lymph node positive status. Furthermore, blocking KiSS1 using a specific small peptide antagonist (p234) impaired TGFβ-mediated cell invasion and MMP9 induction. Together, our results define an essential role of KiSS1 in regulating TGFβ pro-invasive effects and define KiSS1 as a therapeutic new target for triple negative breast cancer.

Phase II study on early start of chemotherapy after excising primary colorectal cancer with distant metastases (Pearl Star 02)

Initiating chemotherapy usually requires a delay of more than 4 weeks after surgically resecting colorectal cancer. However, there is little evidence regarding the required delay interval. We have previously reported a pilot study to determine the safety and feasibility of early initiation of chemotherapy after resecting primary colorectal cancer with distant metastases. We aimed to determine the safety and efficacy of early initiation of chemotherapy after resecting colorectal cancer with distant metastases.

This phase II study (trial number UMIN000006310) was a prospective, single-arm trial. A total of 20 patients (men, 15 and women, 5) were enrolled. They underwent XELOX therapy (130 mg/m² oxaliplatin on day 1+1000 mg/m² capecitabine twice daily on days 1-4) on postoperative day 7 and XELOX+bevacizumab (7.5 mg/kg bevacizumab on day 1) after the second chemotherapy cycle.

Baseline characteristics included a median age of 64 (range, 43-72) years. Surgical procedures included right hemicolectomy in six patients, sigmoidectomy in three, anterior resection in five, and Hartmann procedure in six. All patients started chemotherapy on postoperative day 7. Median progression-free survival was 14.9 months; overall response rate was 80%. Disease control rate was 100%. Grade 3 or higher hemotoxicity and grade 3 or higher non-hematological toxicity was noted in 5.0% and 25.0% of patients, respectively. Postoperative complications were observed in two patients (superficial incisional surgical site infection and ileus).

Early initiation of chemotherapy after surgery is feasible. These findings suggest future changes of the start time of chemotherapy after surgery.

The role of vitamin D in hepatic metastases from colorectal cancer

Colorectal cancer (CRC) represents a significant health burden worldwide, comprising approximately 10% of annual cancer cases globally. Hepatic metastases are the most common site of CRC metastasis, and are the leading cause of death in CRC patients. There is strong epidemiologic evidence for an inverse association between vitamin D status and risk of CRC; however, the role of vitamin D in the natural history of liver metastases has not yet been investigated. Several researchers have proposed hallmarks of metastases; crucially, metastases can be blocked by interrupting just one rate-limiting step. Vitamin D status has been implicated in each proposed hallmark of metastasis. The aim of this review is to examine the potential role for vitamin D in reducing the development of hepatic metastases from CRC and outline the candidate mechanisms by which vitamin D may mediate these effects. The results of ongoing randomised intervention trials are eagerly awaited to determine whether addressing vitamin D insufficiency in CRC patients could reduce the occurrence of liver metastases, and the consequent morbidity and mortality.

Expression of N-WASP is regulated by HiF1α through the hypoxia response element in the N-WASP promoter

Cancer cell migration and invasion involves temporal and spatial regulation of actin cytoskeleton reorganization, which is regulated by the WASP family of proteins such as N-WASP (Neural- Wiskott Aldrich Syndrome Protein). We have previously shown that expression of N-WASP was increased under hypoxic conditions. In order to characterize the regulation of N-WASP expression, we constructed an N-WASP promoter driven GFP reporter construct, N-WASP^pro-GFP. Transfection of N-WASP^pro-GFP construct and plasmid expressing HiF1α (Hypoxia Inducible factor 1α) enhanced the expression of GFP suggesting that increased expression of N-WASP under hypoxic conditions is mediated by HiF1α. Sequence analysis of the N-WASP promoter revealed the presence of two hypoxia response elements (HREs) characterized by the consensus sequence 5′-GCGTG-3′ at -132 bp(HRE1) and at -662 bp(HRE2) relative to transcription start site (TSS). Site-directed mutagenesis of HRE1(-132) but not HRE2(-662) abolished the HiF1α induced activation of N-WASP promoter. Similarly ChIP assay demonstrated that HiF1α bound to HRE1(-132) but not HRE2(-662) under hypoxic condition. MDA-MB-231 cells but not MDA-MB-231^KD cells treated with hypoxia mimicking agent, DMOG showed enhanced gelatin degradation. Similarly MDA-MB-231^KD(N-WASP^pro-N-WASP^R) cells expressing N-WASP^R under the transcriptional regulation of WT N-WASP^pro but not MDA-MB-231^KD(N-WASP^proHRE1-N-WASP^R) cells expressing N-WASP^R under the transcriptional regulation of N-WASP^proHRE1 showed enhanced gelatin degradation when treated with DMOG. Thus indicating the importance of N-WASP in hypoxia induced invadopodia formation. Thus, our data demonstrates that hypoxia-induced activation of N-WASP expression is mediated by interaction of HiF1α with the HRE1(-132) and explains the role of N-WASP in hypoxia induced invadopodia formation.

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Expression of N-WASP expression is enhanced under hypoxia conditions.

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N-WASP is essential for hypoxia induced invasion.

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HiF1α binds to hypoxia response element (HRE) in N-WASP promoter.

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HRE1 is essential for hypoxia induced invadopodia activity

Celastrol negatively regulates cell invasion and migration ability of human osteosarcoma via downregulation of the PI3K/Akt/NF-κB signaling pathway in vitro

Osteosarcoma (OS) is a primary malignant tumor of the bone, with a tendency to metastasize early. Despite the advances in treatment options, more than 30% of patients develop distant metastases, and the prognosis of these patients with metastases is extremely poor. Celastrol has been demonstrated to manifest multiple pharmacological activities, including induction of apoptosis in numerous types of cancer cell lines. Our previous studies have also suggested that Celastrol is capable of inducing apoptosis of human osteosarcoma cells via the mitochondrial-dependent pathway. The purpose of this study was to investigate the effects of Celastrol on the migration and invasion of human osteosarcoma U-2OS cells in vitro. Cell migration and invasion were investigated using wound healing and Boyden chamber Transwell assays. We observed that Celastrol suppressed cell invasion and migration in human osteosarcoma U-2OS cells. Furthermore, protein expression levels of phosphorylated phosphatidylinositol 3-kinase (PI3K), Akt, inhibitor of κB kinase α/β, inhibitor of κB α, nuclear factor-κB (NF-κB subunit p65) and matrix metalloproteinase (MMP)-2 and -9 were measured by western blot analysis. We observed that the PI3K/Akt/NF-κB signaling pathway was inhibited following Celastrol treatment. In addition, the expression levels of MMP-2 and -9 proteins were also reduced significantly following Celastrol treatment. Therefore, we confirmed that Celastrol suppressed osteosarcoma U-2OS cell metastasis via downregulation of the PI3K/Akt/NF-κB signaling pathway in vitro.

Powerful qPCR assays for the early detection of latent invaders: interdisciplinary approaches in clinical cancer research and plant pathology

Latent invaders represent the first step of disease before symptoms occur in the host. Based on recent findings, tumors are considered to be ecosystems in which cancer cells act as invasive species that interact with the native host cell species. Analogously, in plants latent fungal pathogens coevolve within symptomless host tissues. For these reasons, similar detection approaches can be used for an early diagnosis of the invasion process in both plants and humans to prevent or reduce the spread of the disease. Molecular tools based on the evaluation of nucleic acids have been developed for the specific, rapid, and early detection of human diseases. During the last decades, these techniques to assess and quantify the proliferation of latent invaders in host cells have been transferred from the medical field to different areas of scientific research, such as plant pathology. An improvement in molecular biology protocols (especially referring to qPCR assays) specifically designed and optimized for detection in host plants is therefore advisable. This work is a cross-disciplinary review discussing the use of a methodological approach that is employed within both medical and plant sciences. It provides an overview of the principal qPCR tools for the detection of latent invaders, focusing on comparisons between clinical cancer research and plant pathology, and recent advances in the early detection of latent invaders to improve prevention and control strategies.

Mesenchymal-epithelial signalling in tumour microenvironment: role of high-mobility group Box 1

Glucose deprivation, hypoxia and acidosis are characteristic features of the central core of most solid tumours. Myofibroblasts are stromal cells present in many such solid tumours, including those of the colon, and are known to be involved in all stages of tumour progression. HMGB1 is a nuclear protein with an important role in nucleosome stabilisation and gene transcription; it is also released from immune cells and is involved in the inflammatory process. We report that the microenvironmental condition of glucose deprivation is responsible for the active release of HMGB1 from various types of cancer cell lines (HT-29, MCF-7 and A549) under normoxic conditions. Recombinant HMGB1 (10 ng/ml) triggered proliferation in myofibroblast cells via activation of PI3K and MEK1/2. Conditioned medium collected from glucose-deprived HT-29 colon cancer cells stimulated the migration and invasion of colonic myofibroblasts, and these processes were significantly inhibited by immunoneutralising antibodies to HMGB1, RAGE and TLR4, together with specific inhibitors of PI3K and MEK1/2. Our data suggest that HMGB1 released from cancer cells under glucose deprivation is involved in stimulating colonic myofibroblast migration and invasion and that this occurs through the activation of RAGE and TLR4, resulting in the activation of the MAPK and PI3K signalling pathways. Thus, HMGB1 might be released by cancer cells in areas of low glucose in solid tumours with the resulting activation of myofibroblasts and is a potential therapeutic target to inhibit solid tumour growth.

Do cell-autonomous and non-cell-autonomous effects drive the structure of tumor ecosystems?

By definition, a driver mutation confers a growth advantage to the cancer cell in which it occurs, while a passenger mutation does not: the former is usually considered as the engine of cancer progression, while the latter is not. Actually, the effects of a given mutation depend on the genetic background of the cell in which it appears, thus can differ in the subclones that form a tumor. In addition to cell-autonomous effects generated by the mutations, non-cell-autonomous effects shape the phenotype of a cancer cell. Here, we review the evidence that a network of biological interactions between subclones drives cancer cell adaptation and amplifies intra-tumor heterogeneity. Integrating the role of mutations in tumor ecosystems generates innovative strategies targeting the tumor ecosystem's weaknesses to improve cancer treatment.

Lymphangiogenesis and Inflammation-Looking for the "Missing Pieces" of the Puzzle

Several papers about lymphangiogenesis and inflammation focused on the detailed and complicated descriptions of the molecular pathways accompanying both non-tumor and tumor inflammatory-induced lymphatic vessel development. Many authors are tempted to present inflammatory-induced lymphangiogenesis in pathologic conditions neglecting the role of inflammatory cells during embryonic lymphatic vessel development. Some of the inflammatory cells are largely characterized in inflammatory-induced lymphangiogenesis, while others as mast cells, eosinophils, or plasma cells are less studied. No phenotypic characterization of inflammation-activated lymphatic endothelial cell is available in this moment. Another paradox is related to the existence of few papers regarding lymphangiogenesis inside lymphoid organs and for their related pathology. There are still several "missing pieces of such a big puzzle" of lymphangiogenesis and inflammation, with a direct impact on the ineffectiveness of the anti-inflammatory therapy as lymphangiogenesis inhibitors. The present paper will focus on the controversial issues of lymphangiogenesis and inflammation.

The Association of Serum IL-33 and sST2 with Breast Cancer

Breast cancer is one of the most common malignant diseases in women. The main cause of death from breast cancer is its metastases at distant sites in the body. Interleukin-33 (IL-33) is a cytokine of the IL-1 family and found overexpressed in various cancers. The aim of the present study was to explore the association of serum IL-33 and sST2 with breast cancer. Here, the serum levels of Interleukin-33 (IL-33) and sST2 were found significantly higher in breast cancer patients than in healthy volunteers. Serum levels of vascular endothelial growth factor (VEGF), metalloproteinase-11 (MMP-11), and platelet-derived growth factor-C (PDGF-C) were also greater in breast cancer patients compared to healthy volunteers. We found that serum levels of IL-33 or sST2 were positively correlated with the serum levels of VEGF, MMP-11, and PDGF-C. Moreover, breast cancer dataset downloaded from The Cancer Genome Atlas showed that patients with higher level of MMP-11 or PDGF-C expression had shorter survival time than those with lower level of these proteins. In conclusion, IL-33 and sST2 may serve as noninvasive diagnosis markers for breast cancer. IL-33 and sST2 were significantly associated with MMP-11 or PDGF-C which indicated poor prognosis of breast cancer patients.

RNAi-mediated silencing of AQP1 expression inhibited the proliferation, invasion and tumorigenesis of osteosarcoma cells

Aquaporin 1 (AQP1), a member of water channel proteins, functions as a water-selective transporting protein in cell membranes. In recent years, AQP1 has been found to be overexpressed in various tumors. However, the molecular mechanism underlying the biological function of AQP1 in osteosarcoma is still unclear. This study was aimed at elucidating the roles of AQP1 in regulating the biological behavior of osteosarcoma cells. In this study, we found that AQP1 mRNA was elevated in osteosarcoma tissue. High level of AQP1 was associated with poor prognosis in osteosarcoma. Then, we found that knockdown of AQP1 in osteosarcoma cells, U2OS or MG63 cells inhibited cell proliferation and significantly increased cells population in G1 phase. Additionally, suppressing AQP1 expression in osteosarcoma cells dramatically induced cell apoptosis. We also found that down-regulation of AQP1 significantly inhibited cell adhesion and invasion. More importantly, AQP1 knockdown inhibited tumor growth in vivo and prolonged the survival time of nude mice. Gene set enrichment analysis (GSEA) showed that transforming growth factor-β (TGF-β) signaling pathway and focal adhesion genes was correlatively with AQP1 expression. In addition, real time PCR and western blot analysis revealed that expression of TGF-β1/TGF-β2, RhoA and laminin β 2 (LAMB2) was remarkably impaired by AQP1 silencing. In conclusion, AQP1 may be a useful diagnosis and prognosis marker for osteosarcoma. AQP1 knockdown can effectively inhibit cell proliferation, adhesion, invasion and tumorigenesis by targeting TGF-β signaling pathway and focal adhesion genes, which may serve a promising therapeutic strategy for osteosarcoma.

Aberrant expression of osteopontin and E-cadherin indicates radiation resistance and poor prognosis for patients with cervical carcinoma

Radiotherapy is the first-line treatment for all stages of cervical cancer, whether it is used for radical or palliative therapy. However, radioresistance of cervical cancer remains a major therapeutic problem. Consequently, we explored if E-cadherin (a marker of epithelial-mesenchymal transition) and osteopontin could predict radioresistance in patients with locally advanced cervical squamous cell carcinoma (LACSCC). Patients were retrospectively reviewed and 111 patients divided into two groups (radiation-resistant and radiation-sensitive groups) according to progression-free survival (PFS). In pretreated paraffin-embedded tissues, we evaluated E-cadherin and osteopontin expression using immunohistochemical staining. The percentage of patients with high osteopontin but low E-cadherin expression in the radiation-resistant group was significantly higher than those in the radiation-sensitive group (p<0.001). These patients also had a lower 5-year PFS rate (p<0.001). Our research suggests that high osteopontin but low E-cadherin expression can be considered as a negative, independent prognostic factor in patients with LACSCC ([Hazard ratios (95% CI) 6.766 (2.940, 15.572)], p<0.001).

May the remodeling of the Ca²⁺ toolkit in endothelial progenitor cells derived from cancer patients suggest alternative targets for anti-angiogenic treatment?

Endothelial progenitor cells (EPCs) may be recruited from bone marrow to sustain the metastatic switch in a number of solid cancers, including breast cancer (BC) and renal cellular carcinoma (RCC). Preventing EPC mobilization causes tumor shrinkage. Novel anti-angiogenic treatments have been introduced in therapy to inhibit VEGFR-2 signaling; unfortunately, these drugs blocked tumor angiogenesis in pre-clinical murine models, but resulted far less effective in human patients. Understanding the molecular mechanisms driving EPC proliferation and tubulogenesis in cancer patients could outline novel targets for alternative anti-angiogenic treatments. Store-operated Ca²⁺ entry (SOCE) regulates the growth of human EPCs, and it is mediated by the interaction between the endoplasmic reticulum Ca²⁺-sensor, Stim1, and the plasmalemmal Ca²⁺ channels, Orai1 and TRPC1. EPCs do not belong to the neoplastic clone: thus, unlike tumor endothelium and neoplastic cells, they should not remodel their Ca²⁺ toolkit in response to tumor microenvironment. However, our recent work demonstrated that EPCs isolated from naïve RCC patients (RCC-EPCs) undergo a dramatic remodeling of their Ca²⁺ toolkit by displaying a remarkable drop in the endoplasmic reticulum Ca²⁺ content, by down-regulating the expression of inositol-1,4,5-receptors (InsP3Rs), and by up-regulating Stim1, Orai1 and TRPC1. Moreover, EPCs are dramatically less sensitive to VEGF stimulation both in terms of Ca²⁺ signaling and of gene expression when isolated from tumor patients. Conversely, the pharmacological abolition of SOCE suppresses proliferation in these cells. These results question the suitability of VEGFR-2 as a therapeutically relevant target for anti-angiogenic treatments and hint at Orai1 and TRPC1 as more promising alternatives. This article is part of a Special Issue entitled: 13th European Symposium on Calcium.

A mechanically-induced colon cancer cell population shows increased metastatic potential

Background

Metastasis accounts for the majority of deaths from cancer. Although tumor microenvironment has been shown to have a significant impact on the initiation and/or promotion of metastasis, the mechanism remains elusive. We previously reported that HCT-8 colon cancer cells underwent a phenotypic transition from an adhesive epithelial type (E-cell) to a rounded dissociated type (R-cell) via soft substrate culture, which resembled the initiation of metastasis. The objective of current study was to investigate the molecular and metabolic mechanisms of the E-R transition.

Methods

Global gene expressions of HCT-8 E and R cells were measured by RNA Sequencing (RNA-seq); and the results were further confirmed by real-time PCR. Reactive oxygen species (ROS), anoikis resistance, enzyme activity of aldehyde dehydrogenase 3 family, member A1 (ALDH3A1), and in vitro invasion assay were tested on both E and R cells. The deformability of HCT-8 E and R cells was measured by atomic force microscopy (AFM). To study the in vivo invasiveness of two cell types, athymic nude mice were intra-splenically injected with HCT-8 E or R cells and sacrificed after 9 weeks. Incidences of tumor development and metastasis were histologically evaluated and analyzed with Fisher’s exact test.

Results

Besides HCT-8, E-R transition on soft substrates was also seen in three other cancer cell lines (HCT116, SW480 colon and DU145 prostate cancer). The expression of some genes, such as ALDH3A1, TNS4, CLDN2, and AKR1B10, which are known to play important roles in cancer cell migration, invasion, proliferation and apoptosis, were increased in HCT-8 R cells. R cells also showed higher ALDH3A1 enzyme activity, higher ROS, higher anoikis resistance, and higher softness than E cells. More importantly, in vitro assay and in vivo animal models revealed that HCT-8 R cells were more invasive than E cells.

Conclusions

Our comprehensive comparison of HCT-8 E and R cells revealed differences of molecular, phenotypical, and mechanical signatures between the two cell types. To our knowledge, this is the first study that explores the molecular mechanism of E-R transition, which may greatly increase our understanding of the mechanisms of cancer mechanical microenvironment and initiation of cancer metastasis.

Prognostic Significance of β-Catenin, E-Cadherin, and SOX9 in Colorectal Cancer: Results from a Large Population-Representative Series

Robust biomarkers that can precisely stratify patients according to treatment needs are in great demand. The literature is inconclusive for most reported prognostic markers for colorectal cancer (CRC). Hence, adequately reported studies in large representative series are necessary to determine their clinical potential. We investigated the prognostic value of three Wnt signaling-associated proteins, β-catenin, E-cadherin, and SOX9, in a population-representative single-hospital series of 1290 Norwegian CRC patients by performing immunohistochemical analyses of each marker using the tissue microarray technology. Loss of membranous or cytosolic β-catenin and loss of cytosolic E-cadherin protein expression were significantly associated with reduced 5-year survival in 903 patients who underwent major resection (722 evaluable tissue cores) independently of standard clinicopathological high-risk parameters. Pre-specified subgroup analyses demonstrated particular effect for stage IV patients for β-catenin membrane staining (P = 0.018; formal interaction test P = 0.025). Among those who underwent complete resection (714 patients, 568 evaluable), 5-year time-to-recurrence analyses were performed, and stage II patients with loss of cytosolic E-cadherin were identified as an independent high-risk subgroup (P = 0.020, formal interaction test was not significant). Nuclear β-catenin and SOX9 protein, regardless of intracellular location, were not associated with prognosis. In conclusion, the protein expression level of membranous or cytosolic β-catenin and E-cadherin predicts CRC patient subgroups with inferior prognosis.

Carcinoma-associated fibroblasts provide operational flexibility in metastasis

Malignant cancer cells do not act as lone wolves to achieve metastasis, as they exist within a complex ecosystem consisting of an extracellular matrix scaffold populated by carcinoma-associated fibroblasts (CAFs), endothelial cells and immune cells. We recognize local (primary tumor) and distant ecosystems (metastasis). CAFs, also termed myofibroblasts, may have other functions in the primary tumor versus the metastasis. Cellular origin and tumor heterogeneity lead to the expression of specific markers. The molecular characteristics of a CAF remain in evolution since CAFs show operational flexibility. CAFs respond dynamically to a cancer cell's fluctuating demands by shifting profitable signals necessary in metastasis. Local, tissue-resident fibroblasts and mesenchymal stem cells (MSCs) coming from reservoir sites such as bone marrow and adipose tissue are the main progenitor cells of CAFs. CAFs may induce awakening from metastatic dormancy, a major cause of cancer-specific death. Cancer management protocols influence CAF precursor recruitment and CAF activation. Since CAF signatures represent early changes in metastasis, including formation of pre-metastatic niches, we discuss whether liquid biopsies, including exosomes, may detect and monitor CAF reactions allowing optimized prognosis of cancer patients.

Stimuli-induced organ-specific injury enhancement of organotropic metastasis in a spatiotemporal regulation

The relationship between inflammation and tumorigenesis has been established. Recently, inflammation is also reported to be a drive force for cancer metastasis. Further evidences show that various stimuli directly induced-injury in a specific organ can also promote metastasis in this organ, which include epidemiological reports, clinical series and experimental studies. Each type of cancer has preferential sites for metastasis, which is also due to inflammatory factors that are released by primary cancer to act on these sites and indirectly induce injuries on them. Host factors such as stress,fever can also influence distant metastasis in a specific site through stimulation of immune and inflammatory effects. The five aspects support an idea that specific-organ injury directly induced by various stimuli or indirectly induced by primary tumor or host factors activation of proinflammatory modulators can promote metastasis in this organ through a spatiotemporal regulation, which has important implications for personalized prediction, prevention and management of cancer metastasis.

The cancer diaspora: Metastasis beyond the seed and soil hypothesis

Do cancer cells escape the confinement of their original habitat in the primary tumor or are they forced out by ecologic changes in their home niche? Describing metastasis in terms of a simple one-way migration of cells from the primary to the target organs is an insufficient concept to cover the nuances of cancer spread. A diaspora is the scattering of people away from an established homeland. To date, "diaspora" has been a uniquely human term used by social scientists; however, the application of the diaspora concept to metastasis may yield new biologic insights as well as therapeutic paradigms. The diaspora paradigm takes into account, and models, several variables including: the quality of the primary tumor microenvironment, the fitness of individual cancer cell migrants as well as migrant populations, the rate of bidirectional migration of cancer and host cells between cancer sites, and the quality of the target microenvironments to establish metastatic sites. Ecologic scientific principles can be applied to the cancer diaspora to develop new therapeutic strategies. For example, ecologic traps - habitats that lead to the extinction of a species - can be developed to attract cancer cells to a place where they can be better exposed to treatments or to cells of the immune system for improved antigen presentation. Merging the social science concept of diaspora with ecologic and population sciences concepts can inform the cancer field to understand the biology of tumorigenesis and metastasis and inspire new ideas for therapy.

Surgery, wound healing, and metastasis: recent insights and clinical implications

BACKGROUND

Surgery-induced acceleration of tumour growth has been observed since several centuries.

METHODS

We reviewed recent insights from in vitro data, animal experimentation, and clinical studies on how surgery-induced wound healing or resection of a primary cancer influences the tumour-host ecosystem in patients harbouring minimal residual or metastatic disease.

RESULTS

Most of the growth factors, chemokines, and cytokines orchestrating surgical wound healing promote tumour growth, invasion, or angiogenesis. In addition, resection of a primary tumour may accelerate synchronous metastatic growth. In the clinical setting, indirect evidence supports the relevance of the above findings. Randomized clinical trials are underway comparing resection versus observation in metastatic breast and colon cancer with asymptomatic primary tumours.

CONCLUSIONS

In depth knowledge of how surgical intervention alters the tumour-host-metastasis communicating ecosystems could have important implications for clinical decision making in patients with synchronous metastatic disease and for the design and timing of multimodality treatment strategies.

Mesenchymal stem cell-derived CCL-9 and CCL-5 promote mammary tumor cell invasion and the activation of matrix metalloproteinases

Stromal chemokine gradients within the breast tissue microenvironment play a critical role in breast cancer cell invasion, a prerequisite to metastasis. To elucidate which chemokines and mechanisms are involved in mammary cell migration we determined whether mesenchymal D1 stem cells secreted specific chemokines that differentially promoted the invasion of mammary tumor cells in vitro. Results indicate that mesenchymal D1 cells produced concentrations of CCL5 and CCL9 4- to 5-fold higher than the concentrations secreted by 4T1 tumor cells (P < 0.01). Moreover, 4T1 tumor cell invasion toward D1 mesenchymal stem cell conditioned media (D1CM), CCL5 alone, CCL9 alone or a combination CCL5 and CCL9 was observed. The invasion of 4T1 cells toward D1 mesenchymal stem CM was dose-dependently suppressed by pre-incubation with the CCR1/CCR5 antagonist met-CCL5 (P < 0.01). Furthermore, the invasion of 4T1 cells toward these chemokines was prevented by incubation with the broad-spectrum MMP inhibitor GM6001. Additionally, the addition of specific MMP9/MMP13 and MMP14 inhibitors prevented the MMP activities of supernatants collected from 4T1 cells incubated with D1CM, CCL5 or CCL9. Taken together these data highlight the role of CCL5 and CCL9 produced by mesenchymal stem cells in mammary tumor cell invasion.

Expression and clinical significance of FAK, ILK, and PTEN in salivary adenoid cystic carcinoma

CONCLUSION

Focal adhesion kinase (FAK) and integrin-linked kinase (ILK) are highly expressed in salivary adenoid cystic carcinoma (SACC), especially metastatic SACC, suggesting their potential role as prognostic markers for SACC.

OBJECTIVES

This study aimed to investigate the expression of FAK, ILK, and phosphatase and tensin homolog deleted on chromosome ten (PTEN) in SACC tissues and the clinical significance.

METHODS

PAK and ILK expression in samples from 50 cases of SACC and 12 subjects with normal salivary glands was detected by immunohistochemical analysis. PAK and ILK expression in SACC cell lines was detected by RT-PCR and Western blot analysis.

RESULTS

The positive rate of PAK and ILK staining was 94% (47/50) and 48% (24/50) in SACC, respectively, significantly higher than in normal salivary gland tissues (p < 0.05). However, the positive rate of PTEN staining was 30% (15/50), significantly lower than in normal salivary gland tissues (p < 0.05). Pearson analysis showed that FAK expression was positively correlated with ILK expression but negatively correlated with PTEN expression in SACC tissues. FAK and ILK expression was positively associated with advanced stage, solid histological subtype, perineural invasion, and distant metastasis of SACC (p < 0.05). In addition, FAK and ILK expression at both mRNA and protein levels was significantly higher in highly metastatic SACC-LM cells than low-metastatic SACC-83 cells.

Role of the nervous system in cancer metastasis

The notion that tumors lack innervation was proposed several years ago. However, nerve fibers are irregulatedly found in some tumor tissues. Their terminals interaction with cancer cells are considered to be neuro-neoplastic synapses. Moreover, neural-related factors, which are important players in the development and activity of the nervous system, have been found in cancer cells. Thus, they establish a direct connection between the nervous system and tumor cells. They modulate the process of metastasis, including degradation of base membranes, cancer cell invasion, migration, extravasation and colonization. Peripheral nerve invasion provides another pathway for the spread of cancer cells when blood and lymphatic metastases are absent, which is based on the interactions between the microenvironments of nerve fibers and tumor cells. The nervous system also modulates angiogenesis, the tumor microenvironment, bone marrow, immune functions and inflammatory pathways to influence metastases. Denervation of the tumor has been reported to enhance cancer metastasis. Stress, social isolation and other emotional factors may increase distant metastasis through releasing hormones from the brain, the hypothalamic-pituitary-adrenal axis and autonomic nervous system. Disruption of circadian rhythms will also promote cancer metastasis through direct and indirect actions of the nervous system. Therefore, the nervous system plays an important role in cancer metastasis.

Fluctuating roles of matrix metalloproteinase-9 in oral squamous cell carcinoma

One hallmark of cancer is the degradation of the extracellular matrix (ECM), which is caused by proteinases. In oral cancers, matrix metalloproteinases (MMPs), especially MMP-9, are associated with this degradation. MMPs break down the ECM allowing cancer to spread; they also release various factors from their cryptic sites, including cytokines. These factors modulate cell behavior and enhance cancer progression by regulating angiogenesis, migration, proliferation, and invasion. The development of early metastases is typical for oral cancer, and increased MMP-9 expression is associated with a poor disease prognosis. However, many studies fail to relate MMP-9 expression with metastasis formation. Contrary to earlier models, recent studies show that MMP-9 plays a protective role in oral cancers. Therefore, the role of MMP-9 is complicated and may fluctuate throughout the different types and stages of oral cancers.

Xanthones from mangosteen extracts as natural chemopreventive agents: potential anticancer drugs

Despite decades of research, the treatment and management of malignant tumors still remain a formidable challenge for public health. New strategies for cancer treatment are being developed, and one of the most promising treatment strategies involves the application of chemopreventive agents. The search for novel and effective cancer chemopreventive agents has led to the identification of various naturally occurring compounds. Xanthones, from the pericarp, whole fruit, heartwood, and leaf of mangosteen (Garcinia mangostana Linn., GML), are known to possess a wide spectrum of pharmacologic properties, including antioxidant, anti- tumor, anti-allergic, anti-inflammatory, anti-bacterial, anti-fungal, and anti-viral activities. The potential chemopreventive and chemotherapeutic activities of xanthones have been demonstrated in different stages of carcinogenesis (initiation, promotion, and progression) and are known to control cell division and growth, apoptosis, inflammation, and metastasis. Multiple lines of evidence from numerous in vitro and in vivo studies have confirmed that xanthones inhibit proliferation of a wide range of human tumor cell types by modulating various targets and signaling transduction pathways. Here we provide a concise and comprehensive review of preclinical data and assess the observed anticancer effects of xanthones, supporting its remarkable potential as an anticancer agent.

Epithelial E- and P-cadherins: role and clinical significance in cancer

E-cadherin and P-cadherin are major contributors to cell-cell adhesion in epithelial tissues, playing pivotal roles in important morphogenetic and differentiation processes during development, and in maintaining integrity and homeostasis in adult tissues. It is now generally accepted that alterations in these two molecules are observed during tumour progression of most carcinomas. Genetic or epigenetic alterations in E- and P-cadherin-encoding genes (CDH1 and CDH3, respectively), or alterations in their proteins expression, often result in tissue disorder, cellular de-differentiation, increased invasiveness of tumour cells and ultimately in metastasis. In this review, we will discuss the major properties of E- and P-cadherin molecules, its regulation in normal tissue, and their alterations and role in cancer, with a specific focus on gastric and breast cancer models.

Disrupting the networks of cancer

Ecosystems are interactive systems involving communities of species and their abiotic environment. Tumors are ecosystems in which cancer cells act as invasive species interacting with native host cell species in an established microenvironment within the larger host biosphere. At its heart, to study ecology is to study interconnectedness. In ecologic science, an ecologic network is a representation of the biotic interactions in an ecosystem in which species (nodes) are connected by pairwise interactions (links). Ecologic networks and signaling network models have been used to describe and compare the structures of ecosystems. It has been shown that disruption of ecologic networks through the loss of species or disruption of interactions between them can lead to the destruction of the ecosystem. Often, the destruction of a single node or link is not enough to disrupt the entire ecosystem. The more complex the network and its interactions, the more difficult it is to cause the extinction of a species, especially without leveraging other aspects of the ecosystem. Similarly, successful treatment of cancer with a single agent is rarely enough to cure a patient without strategically modifying the support systems conducive to survival of cancer. Cancer cells and the ecologic systems they reside in can be viewed as a series of nested networks. The most effective new paradigms for treatment will be developed through application of scaled network disruption.

The molecular biology of brain metastasis

Metastasis to the central nervous system (CNS) remains a major cause of morbidity and mortality in patients with systemic cancers. Various crucial interactions between the brain environment and tumor cells take place during the development of the cancer at its new location. The rapid expansion in molecular biology and genetics has advanced our knowledge of the underlying mechanisms involved, from invasion to final colonization of new organ tissues. Understanding the various events occurring at each stage should enable targeted drug delivery and individualized treatments for patients, with better outcomes and fewer side effects. This paper summarizes the principal molecular and genetic mechanisms that underlie the development of brain metastasis (BrM).

Recent developments in myofibroblast biology: paradigms for connective tissue remodeling

The discovery of the myofibroblast has opened new perspectives for the comprehension of the biological mechanisms involved in wound healing and fibrotic diseases. In recent years, many advances have been made in understanding important aspects of myofibroblast basic biological characteristics. This review summarizes such advances in several fields, such as the following: i) force production by the myofibroblast and mechanisms of connective tissue remodeling; ii) factors controlling the expression of α-smooth muscle actin, the most used marker of myofibroblastic phenotype and, more important, involved in force generation by the myofibroblast; and iii) factors affecting genesis of the myofibroblast and its differentiation from precursor cells, in particular epigenetic factors, such as DNA methylation, microRNAs, and histone modification. We also review the origin and the specific features of the myofibroblast in diverse fibrotic lesions, such as systemic sclerosis; kidney, liver, and lung fibrosis; and the stromal reaction to certain epithelial tumors. Finally, we summarize the emerging strategies for influencing myofibroblast behavior in vitro and in vivo, with the ultimate goal of an effective therapeutic approach for myofibroblast-dependent diseases.

DM-1, sodium 4-[5-(4-hydroxy-3-methoxyphenyl)-3-oxo-penta-1,4-dienyl]-2-methoxy-phenolate: a curcumin analog with a synergic effect in combination with paclitaxel in breast cancer treatment

This paper describes a new method for the preparation of sodium 4-[5-(4-hydroxy-3-methoxyphenyl)-3-oxo-penta-1,4-dienyl]-2-methoxy-phenolate, DM-1, and 3-oxo-penta-1,4-dienyl-bis (2-methoxy-phenolate), DM-2. The aim of this work was to evaluate the antitumor effects of DM-1 in adjuvant chemotherapy for breast cancer treatment. Mice bearing mammary adenocarcinomas (Ehrlich ascites tumors) were treated with paclitaxel alone, DM-1 alone, and paclitaxel + DM-1. Tumor samples were used to perform cytological analysis by the Papanicolaou method and apoptosis analysis by annexin V and phosphorylated caspase 3. The paclitaxel + DM-1 group had decreased tumor areas and tumor volumes, and the frequency of metastasis was significantly reduced. This caused a decrease in cachexia, which is usually caused by the tumor. Furthermore, treatment with paclitaxel + DM-1 and DM-1 alone increased the occurrence of apoptosis up to 40% in tumor cells, which is 35% more than in the group treated with paclitaxel alone. This cell death was mainly caused through phosphorylated caspase 3 (11% increase in paclitaxel + DM-1 compared to the paclitaxel group), as confirmed by reduced malignancy criteria in the ascitic fluid. DM-1 emerges as a potential treatment for breast cancer and may act as an adjuvant in chemotherapy, enhancing antitumor drug activity with reduced side effects.

Current operative management of breast cancer: an age of smaller resections and bigger cures

Surgical resection was the first effective treatment for breast cancer and remains the most important treatment modality for curative intent. Refinements in operative techniques along with the use of adjuvant radiotherapy and advanced chemotherapeutic agents have facilitated increasingly focused breast cancer operations. Surgical management of breast cancer has shifted from extensive and highly morbid procedures, to the modern concept obtaining the best possible cosmetic result in tandem with the appropriate oncological resection. An ever-growing comprehension of breast cancer biology has led to substantial advances in molecular diagnosis and targeted therapies. An emerging frontier involves the breast cancer microenvironment, as a thorough understanding, while currently lacking, represents a critical opportunity for diagnosis and treatment. Collectively, these improvements will continue to push all therapeutic interventions, including operative, toward the goal of becoming more focused, targeted, and less morbid.

MYCT1-TV, a novel MYCT1 transcript, is regulated by c-Myc and may participate in laryngeal carcinogenesis

BACKGROUND

MYCT1, a putative target of c-Myc, is a novel candidate tumor suppressor gene cloned from laryngeal squamous cell carcinoma (LSCC). Its transcriptional regulation and biological effects on LSCC have not been clarified.

METHODOLOGY/PRINCIPAL FINDINGS

Using RACE assay, we cloned a 1106 bp transcript named Myc target 1 transcript variant 1 (MYCT1-TV) and confirmed its transcriptional start site was located at 140 bp upstream of the ATG start codon of MYCT1-TV. Luciferase, electrophoretic mobility shift and chromatin immunoprecipitation assays confirmed c-Myc could regulate the promoter activity of MYCT1-TV by specifically binding to the E-box elements within -886 to -655 bp region. These results were further verified by site-directed mutagenesis and RNA interference (RNAi) assays. MYCT1-TV and MYCT1 expressed lower in LSCC than those in paired adjacent normal laryngeal tissues, and overexpression of MYCT1-TV and MYCT1 could inhibit cell proliferation and invasion and promote apoptosis in LSCC cells.

CONCLUSIONS/SIGNIFICANCE

Our data indicate that MYCT1-TV, a novel MYCT1 transcript, is regulated by c-Myc and down-regulation of MYCT1-TV/MYCT1 could contribute to LSCC development and function.

TGF-β signaling in breast cancer cell invasion and bone metastasis

The contribution of transforming growth factor β (TGF-β) signaling to breast cancer has been studied for more than two decades. In an early phase TGF-β may act as a tumour suppressor, while later, when cells have become resistant to its anti-mitogenic effects, the role of TGF-β switches towards malignant conversion and progression. TGF-β stimulates cell invasion and modifies the microenvironment to the advantage of cancer cells. Studies have shown that TGF-β promotes bone and lung metastasis via different mechanisms. The therapeutic strategies to target the TGF-β pathway in breast cancer are becoming increasingly clear. This review will focus on the role TGF-β in breast cancer invasion and metastasis.