WISP3 and RhoC guanosine triphosphatase cooperate in the development of inflammatory breast cancer

CCN proteins: opportunities for clinical studies-a personal perspective

The diverse members of the CCN family now designated as CCN1(CYR61), CCN2 (CTGF), CCN3(NOV), CCN4(WISP1), CCN5(WISP2), CCN6(WISP3) are a conserved matricellular family of proteins exhibiting a spectrum of functional properties throughout all organs in the body. Interaction with cell membrane receptors such as integrins trigger intracellular signaling pathways. Proteolytically cleaved fragments (constituting the active domains) can be transported to the nucleus and perform transcriptional relevant functional activities. Notably, as also found in other protein families some members act opposite to others creating a system of functionally relevant checks and balances. It has become apparent that these proteins are secreted into the circulation, are quantifiable, and can serve as disease biomarkers. How they might also serve as homeostatic regulators is just becoming appreciated. In this review I have attempted to highlight the most recent evidence under the subcategories of cancer and non-cancer relevant that could lead to potential therapeutic approaches or ideas that can be factored into clinical advances. I have added my own personal perspective on feasibility.

WISP3 suppresses ESCC progression by inhibiting the IGF-2-IGF1R-AKT signaling cascade

Esophageal squamous cell carcinoma (ESCC) is a major health problem worldwide, especially in the Chinese population. However, the intrinsic molecular mechanisms of ESCC progression are largely unclear, thus there is an unmet need to identify essential genes governing this disease. Here, we discovered WISP3, an important member of the CCN family, is markedly downregulated in ESCC tissues compared to the normal esophageal epithelium. Downregulation of WISP3 in cancer tissue correlates with worse overall survival of ESCC patients. Using ESCC cell lines as models, we found that forced expression of WISP3 not only suppressed proliferation and migration of cancer cells in vitro, but also inhibited ESCC tumor growth and metastasis in vivo. On the contrary, WISP3 depletion strongly promoted the tumorigenicity of ESCC cells. Mechanistically, we found that WISP3 negates the activity of AKT via inhibiting the IGF-2-IGF1R signaling cascade, which mediates the tumor-suppressive function of WISP3 in esophageal cancers. Together, we identified a novel factor driving the development of ESCC, and revealed a potential therapeutic target for ESCC treatment.

Decorin-mediated suppression of tumorigenesis, invasion, and metastasis in inflammatory breast cancer

Inflammatory breast cancer (IBC) is a clinically distinct and highly aggressive form of breast cancer with rapid onset and a strong propensity to metastasize. The molecular mechanisms underlying the aggressiveness and metastatic propensity of IBC are largely unknown. Herein, we report that decorin (DCN), a small leucine-rich extracellular matrix proteoglycan, is downregulated in tumors from patients with IBC. Overexpression of DCN in IBC cells markedly decreased migration, invasion, and cancer stem cells in vitro and inhibited tumor growth and metastasis in IBC xenograft mouse models. Mechanistically, DCN functioned as a suppressor of invasion and tumor growth in IBC by destabilizing E-cadherin and inhibiting EGFR/ERK signaling. DCN physically binds E-cadherin in IBC cells and accelerates its degradation through an autophagy-linked lysosomal pathway. We established that DCN inhibits tumorigenesis and metastasis in IBC cells by negatively regulating the E-cadherin/EGFR/ERK axis. Our findings offer a potential therapeutic strategy for IBC, and provide a novel mechanism for IBC pathobiology.

Xiaoding Hu et al. find that expression of the proteoglycan decorin is decreased in patients with inflammatory breast cancer compared to normal breast tissue and some other types of breast cancer. They demonstrate that decorin acts as a tumor suppressor in cancer cells and human xenograft mouse models by destabilizing the E-cadherin-EGFR signaling axis, and their findings suggest potential therapeutic strategies for this aggressive breast cancer.

Targeting Signaling Pathways in Inflammatory Breast Cancer

Inflammatory breast cancer (IBC), although rare, is the most aggressive type of breast cancer. Only 2-4% of breast cancer cases are classified as IBC, but-owing to its high rate of metastasis and poor prognosis-8% to 10% of breast cancer-related mortality occur in patients with IBC. Currently, IBC-specific targeted therapies are not available, and there is a critical need for novel therapies derived via understanding novel targets. In this review, we summarize the biological functions of critical signaling pathways in the progression of IBC and the preclinical and clinical studies of targeting these pathways in IBC. We also discuss studies of crosstalk between several signaling pathways and the IBC tumor microenvironment.

RhoC regulates radioresistance via crosstalk of ROCK2 with the DNA repair machinery in cervical cancer

Background

Radioresistance remains a challenge to the successful treatment of various tumors. Intrinsic factors like alterations in signaling pathways regulate response to radiation. RhoC, which has been shown to modulate several tumor phenotypes has been investigated in this report for its role in radioresistance. In vitro and clinical sample-based studies have been performed to understand its contribution to radiation response in cervical cancer and this is the first report to establish the role of RhoC and its effector ROCK2 in cervical cancer radiation response.

Methods

Biochemical, transcriptomic and immunological approaches including flow cytometry and immunofluorescence were used to understand the role of RhoC and ROCK2. RhoC variants, siRNA and chemical inhibitors were used to alter the function of RhoC and ROCK2. Transcriptomic profiling was performed to understand the gene expression pattern of the cells. Live sorting using an intracellular antigen has been developed to isolate the cells for transcriptomic studies.

Results

Enhanced expression of RhoC conferred radioprotection on the tumor cells while inhibition of RhoC resulted in sensitization of cells to radiation. The RhoC overexpressing cells had a better DNA repair machinery as observed using transcriptomic analysis. Similarly, overexpression of ROCK2, protected tumor cells against radiation while its inhibition increased radiosensitivity in vitro. Further investigations revealed that ROCK2 inhibition abolished the radioresistance phenotype, conferred by RhoC on SiHa cells, confirming that it is a downstream effector of RhoC in this context. Additionally, transcriptional analysis of the live sorted ROCK2 high and ROCK2 low expressing SiHa cells revealed an upregulation of the DNA repair pathway proteins. Consequently, inhibition of ROCK2 resulted in reduced expression of pH2Ax and MRN complex proteins, critical to repair of double strand breaks. Clinical sample-based studies also demonstrated that ROCK2 inhibition sensitizes tumor cells to irradiation.

Conclusions

Our data primarily indicates that RhoC and ROCK2 signaling is important for the radioresistance phenotype in cervical cancer tumor cells and is regulated via association of ROCK2 with the proteins of DNA repair pathway involving pH2Ax, MRE11 and RAD50 proteins, partly offering insights into the mechanism of radioresistance in tumor cells. These findings highlight RhoC-ROCK2 signaling involvement in DNA repair and urge the need for development of these molecules as targets to alleviate the non-responsiveness of cervical cancer tumor cells to irradiation treatment.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1385-7) contains supplementary material, which is available to authorized users.

Effects of microbiota-directed foods in gnotobiotic animals and undernourished children

To examine the contributions of impaired gut microbial community development to childhood undernutrition, we combined metabolomic and proteomic analyses of plasma samples with metagenomic analyses of fecal samples to characterize the biological state of Bangladeshi children with severe acute malnutrition (SAM) as they transitioned, after standard treatment, to moderate acute malnutrition (MAM) with persistent microbiota immaturity. Host and microbial effects of microbiota-directed complementary food (MDCF) prototypes targeting weaning-phase bacterial taxa underrepresented in SAM and MAM microbiota were characterized in gnotobiotic mice and gnotobiotic piglets colonized with age- and growth-discriminatory bacteria. A randomized, double-blind controlled feeding study identified a lead MDCF that changes the abundances of targeted bacteria and increases plasma biomarkers and mediators of growth, bone formation, neurodevelopment, and immune function in children with MAM.

The emerging role of WISP proteins in tumorigenesis and cancer therapy

Accumulated evidence has demonstrated that WNT1 inducible signaling pathway protein (WISP) genes, which belong to members of the CCN growth factor family, play a pivotal role in tumorigenesis and progression of a broad spectrum of human cancers. Mounting studies have identified that WISP proteins (WISP1-3) exert different biological functions in various human malignancies. Emerging evidence indicates that WISP proteins are critically involved in cell proliferation, apoptosis, invasion and metastasis in cancers. Because the understanding of a direct function of WISP proteins in cancer development and progression has begun to emerge, in this review article, we describe the physiological function of WISP proteins in a variety of human cancers. Moreover, we highlight the current understanding of how the WISP protein is involved in tumorigenesis and cancer progression. Furthermore, we discuss that targeting WISP proteins could be a promising strategy for the treatment of human cancers. Hence, the regulation of WISP proteins could improve treatments for cancer patients.

Comparative aspects of canine and human inflammatory breast cancer

Inflammatory breast cancer (IBC) in humans is the most aggressive form of mammary gland cancer and shares clinical, pathologic, and molecular patterns of disease with canine inflammatory mammary carcinoma (CIMC). Despite the use of multimodal therapeutic approaches, including targeted therapies, the prognosis for IBC/CIMC remains poor. The aim of this review is to critically analyze IBC and CIMC in terms of biology and clinical features. While rodent cancer models have formed the basis of our understanding of cancer biology, the translation of this knowledge into improved outcomes has been limited. However, it is possible that a comparative "one health" approach to research, using a natural canine model of the disease, may help advance our knowledge on the biology of the disease. This will translate into better clinical outcomes for both species. We propose that CIMC has the potential to be a useful model for developing and testing novel therapies for IBC. Further, this strategy could significantly improve and accelerate the design and establishment of new clinical trials to identify novel and improved therapies for this devastating disease in a more predictable way.

Interferon-induced transmembrane protein 1 (IFITM1) overexpression enhances the aggressive phenotype of SUM149 inflammatory breast cancer cells in a signal transducer and activator of transcription 2 (STAT2)-dependent manner

Background

Inflammatory breast cancer (IBC) is a very aggressive and lethal subtype of breast cancer that accounts for about 4 % of all breast cancers diagnosed in the United States. Despite the efforts of several investigators to identify the molecular factors driving the aggressive phenotype of IBC, a great deal is still unknown about the molecular underpinnings of the disease. In the present study, we investigated the role of interferon-induced transmembrane protein 1 (IFITM1), a well-known interferon-stimulated gene (ISG), in promoting the aggressiveness of SUM149 IBC cells.

Methods

Western blot and real-time polymerase chain reaction analyses were performed to assess the protein and messenger RNA (mRNA) levels of IFITM1 and other ISGs in three IBC cell lines: SUM149, MDA-IBC-3, and SUM190. IFITM1 expression and cellular localization were assessed by using immunofluorescence, while the tumorigenic potential was assessed by performing cell migration, invasion, and colony formation assays. Small interfering RNA and short hairpin RNA knockdowns, enzyme-linked immunosorbent assays, and luciferase assays were performed to determine the functional significance of IFITM1 and signal transducers and activators of transcription 1 and 2 (STAT1/2) in SUM149 cells.

Results

We found that IFITM1 was constitutively overexpressed at the mRNA and protein levels in triple-negative SUM149 IBC cells, but that it was not expressed in SUM190 and MDA-IBC-3 IBC cells, and that suppression of IFITM1 or blockade of the IFNα signaling pathway significantly reduced the aggressive phenotype of SUM149 cells. Additionally, we found that knockdown of STAT2 abolished IFITM1 expression and IFITM1 promoter activity in SUM149 cells and that loss of STAT2 significantly inhibited the ability of SUM149 cells to proliferate, migrate, invade, and form 2-D colonies. Notably, we found that STAT2-mediated activation of IFITM1 was particularly dependent on the chromatin remodeler brahma-related gene 1 (BRG1), which was significantly elevated in SUM149 cells compared with SUM190 and MDA-IBC-3 cells.

Conclusions

These findings indicate that overexpression of IFITM1 enhances the aggressive phenotype of triple-negative SUM149 IBC cells and that this effect is dependent on STAT2/BRG1 interaction. Further studies are necessary to explore the potential of IFITM1 as a novel therapeutic target and prognostic marker for some subtypes of IBCs.

Electronic supplementary material

The online version of this article (doi:10.1186/s13058-016-0683-7) contains supplementary material, which is available to authorized users.

WISP3 is highly expressed in a subset of colorectal carcinomas with a better prognosis

Outlier genes with marked overexpression in subsets of cancers like ERBB2 have potential for the identification of gene classifiers and therapeutic targets for the appropriate subpopulation. In this study, using the cancer outlier profile analysis strategy, we identified WNT1-inducible-signaling pathway protein 3 (WISP3) as an outlier gene that is highly expressed in a subset of colorectal cancers (CRCs) from The Cancer Genome Atlas dataset. A meta-cancer outlier profile analysis and immunohistochemistry experiment to validate the outlier expression model of WISP3 in CRC was then performed. Our immunohistochemical results indicated that WISP3 was more frequently seen in the small tumors, and there was a significant association between its overexpression with a good prognosis. Furthermore, in the multivariable model, WISP3 outlier expression retained significance for overall survival. In summary, in this study, we identified an outlier gene WISP3 overexpressed in a subset of CRC having less aggressive characteristics and a better prognosis. We suggest WISP3 may provide more accurate and precise information regarding CRC population classification.

Inflammation and Oral Cancer: An Update Review on Targeted Therapies

In the recent past, numerous inflammation-mediated molecular pathways have been explored and studied as important events in carcinogenesis with respect to oral squamous cell carcinoma (OSCC). These pathways are engaged in numerous stages during tumorigenesis; which includes processes, like initiation, promotion, malignant conversion, invasion and metastasis. The inflammation-mediated/related carcinogenesis pathways reported in OSCC involves COX-2, epidermal growth factor receptor (EGFR), p38a MAP kinase, NF-kB, STAT, RhoC, PPARy, etc. Many researchers are trying to target these pathways to explore more effective therapeutic interventions in OSCC. The aim of the present paper is to briefly discuss these pathways, with special emphasis on the therapeutic utilities. The therapeutic targets for the aforementioned pathways were searched in databases pubmed and scopus with no restriction to date of publication. Articles published in English medical literature on OSCC were selected for discussion. The recent combinations, modifications in dosage and frequency, or the use of new anti-inflammatory compounds, may exemplify the next generation care for OSCC.

Transcriptome markers of viral persistence in naturally-infected andes virus (bunyaviridae) seropositive long-tailed pygmy rice rats

Long-tailed pygmy rice rats (Oligoryzomys longicaudatus) are principal reservoir hosts of Andes virus (ANDV) (Bunyaviridae), which causes most hantavirus cardiopulmonary syndrome cases in the Americas. To develop tools for the study of the ANDV-host interactions, we used RNA-Seq to generate a de novo transcriptome assembly. Splenic RNA from five rice rats captured in Chile, three of which were ANDV-infected, was used to generate an assembly of 66,173 annotated transcripts, including noncoding RNAs. Phylogenetic analysis of selected predicted proteins showed similarities to those of the North American deer mouse (Peromyscus maniculatus), the principal reservoir of Sin Nombre virus (SNV). One of the infected rice rats had about 50-fold more viral burden than the others, suggesting acute infection, whereas the remaining two had levels consistent with persistence. Differential expression analysis revealed distinct signatures among the infected rodents. The differences could be due to 1) variations in viral load, 2) dimorphic or reproductive differences in splenic homing of immune cells, or 3) factors of unknown etiology. In the two persistently infected rice rats, suppression of the JAK-STAT pathway at Stat5b and Ccnot1, elevation of Casp1, RIG-I pathway factors Ppp1cc and Mff, and increased FC receptor-like transcripts occurred. Caspase-1 and Stat5b activation pathways have been shown to stimulate T helper follicular cell (T_FH) development in other species. These data are also consistent with reports suggestive of T_FH stimulation in deer mice experimentally infected with hantaviruses. In the remaining acutely infected rice rat, the apoptotic pathway marker Cox6a1 was elevated, and putative anti-viral factors Abcb1a, Fam46c, Spp1, Rxra, Rxrb, Trmp2 and Trim58 were modulated. Transcripts for preproenkephalin (Prenk) were reduced, which may be predictive of an increased T cell activation threshold. Taken together, this transcriptome dataset will permit rigorous examination of rice rat-ANDV interactions and may lead to better understanding of virus ecology.

Anoikis evasion in inflammatory breast cancer cells is mediated by Bim-EL sequestration

Inflammatory breast cancer (IBC) is a rare and highly invasive type of breast cancer, and patients diagnosed with IBC often face a very poor prognosis. IBC is characterized by the lack of primary tumor formation and the rapid accumulation of cancerous epithelial cells in the dermal lymphatic vessels. Given that normal epithelial cells require attachment to the extracellular matrix (ECM) for survival, a comprehensive examination of the molecular mechanisms underlying IBC cell survival in the lymphatic vessels is of paramount importance to our understanding of IBC pathogenesis. Here we demonstrate that, in contrast to normal mammary epithelial cells, IBC cells evade ECM-detachment-induced apoptosis (anoikis). ErbB2 and EGFR knockdown in KPL-4 and SUM149 cells, respectively, causes decreased colony growth in soft agar and increased caspase activation following ECM detachment. ERK/MAPK signaling was found to operate downstream of ErbB2 and EGFR to protect cells from anoikis by facilitating the formation of a protein complex containing Bim-EL, LC8, and Beclin-1. This complex forms as a result of Bim-EL phosphorylation on serine 59, and thus Bim-EL cannot localize to the mitochondria and cause anoikis. These results reveal a novel mechanism that could be targeted with innovative therapeutics to induce anoikis in IBC cells.

Breast cancer in Morocco: a literature review

In Morocco, breast cancer is the most prevalent cancer in women and a major public health problem. Several Moroccan studies have focused on studying this disease, but more are needed, especially at the genetic and molecular levels. It is therefore interesting to establish the genetic and molecular profile of Moroccan patients with breast cancer. In this paper, we will highlight some pertinent hypotheses that may enhance breast cancer care in Moroccan patients. This review will give a precise description of breast cancer in Morocco and propose some new markers for detection and prediction of breast cancer prognosis.

Silencing of WISP3 suppresses gastric cancer cell proliferation and metastasis and inhibits Wnt/β-catenin signaling

CCN6/Wnt1-inducible signaling protein-3 (CCN6/WISP3) is a cysteine-rich protein that belongs to the CCN (Cyr61, CTGF, Nov) family of matricellular proteins, which are often dysregulated in cancers. However, the functional role and clinical significance of WISP3 in gastric cancer remain unclear. In this study, we found that silencing of WISP3 suppressed gastric cancer cell proliferation, migration and invasion. Cell adhesion to collagens (collagen I and IV), but not to fibronectin, were significantly inhibited by silencing of WISP3. Furthermore, silencing of WISP3 prevented β-catenin transferring from cell cytoplasm to nuclear, and suppressed canonical Wnt/β-catenin signaling and its downstream target genes, cyclin D1 and TCF-4. By immunohistochemical analysis of 379 patients, we found that the expression of WISP3 is closely associated with gastric cancer size and tumor invasion, and indicates a poor prognosis in both test cohort (253 patients) and validation cohort (126 patients). Moreover, the expression of WISP3 was positively correlated with the expression of cyclin D1 and TCF-4 in gastric cancer tissues. Taken together, our data suggests that WISP3 might be a promising prognostic factor and WISP3-Wnt/β-catenin axis may be a new therapeutic target for the intervention of gastric cancer growth and metastasis.

Expression profile of inflammatory breast cancer

Inflammatory breast cancer is characterized by high malignancy, early and rapid lymphogenic and hematogenic metastasizing, and high mortality. The diagnosis of this form of cancer is based fully on the clinical criteria. Whole transcriptome analysis of tumor tissue specimens from patients with inflammatory breast cancer detected 137 differentially expressed mRNA (17 genes with low expression and 120 with high expression). Genes involved in the organization of inflammatory process, chemotaxis, and transcription regulation were active in the process of pathogenesis of inflammatory breast cancer.

Inflammatory breast cancer in north Africa: comparison of clinical and molecular epidemiologic characteristics of patients from Egypt, Tunisia, and Morocco

Understanding molecular characteristics that distinguish inflammatory breast cancer (IBC) from non-IBC is crucial for elucidating breast cancer etiology and management. We included 3 sets of patients from Egypt (48 IBC and 64 non-IBC), Tunisia (24 IBC and 40 non-IBC), and Morocco (42 IBC and 41 non-IBC). Egyptian IBC patients had the highest combined erythema, edema, peau d'orange, and metastasis among the 3 IBC groups. Egyptian IBC tumors had the highest RhoC expression than Tunisians and Moroccan IBCs (87% vs. 50%, vs. 38.1, for the 3 countries, respectively). Tumor emboli were more frequent in Egyptian IBC than non-IBC (Mean ± SD: 14.1 ± 14.0 vs. 7.0 ± 12.9, respectively) (P < 0.001) and Tunisians (Mean ± SD: 3.4 ± 2.5 vs. 1.9 ± 2.0, respectively) (P < 0.01). There was no difference of emboli in Moroccan tumors (1.7 ± 1.2 vs. 1.8 ± 1.2 for IBC and non-IBC, respectively (P=0.66). This study illustrates that RhoC overexpression and tumor emboli are more frequent in IBC relative to non-IBC from Egypt and Tunisia. Tumors of Moroccans were significantly different from Egyptian and Tunisian tumors for RhoC expression and emboli. Future studies should focus on relating epidemiologic factors and clinical pictures to molecular features of IBC in these and other populations.

How do I treat inflammatory breast cancer?

Inflammatory breast cancer (IBC) is an uncommon and aggressive presentation of locally advanced breast cancer that is potentially curable when localized but may be associated with distant metastasis in up to one-third of patients at presentation. The diagnosis of IBC is made based on clinical features, including the presence of skin edema and erythema involving at least one-third of the breast, with or without a mass, and usually associated with dermal lymphatic invasion (DLI) on skin biopsy. Management requires combined modality therapy, including neoadjuvant chemotherapy with an anthracycline and taxane-based regimen, followed by surgery and radiotherapy, plus concurrent anti-HER2 therapy for HER2-positive disease, and endocrine therapy for at least 5 years after surgery for estrogen-receptor-positive disease (Fig. 1). There have been few large clinical trials focused on IBC; therefore, most data regarding treatment are derived from retrospective analyses, small studies, and extrapolation of results from trials of noninflammatory locally advanced breast cancer. Patients with IBC should be encouraged to enroll in clinical trials whenever possible. In addition, further research into the biology of IBC may help to elucidate the mechanisms underlying its aggressive clinical behavior and to assist in the development of therapies targeted for this specific population.

Expression of ALDH1 in breast invasive ductal carcinoma: an independent predictor of early tumor relapse

Background

The specific mechanism underlying the contribution of the Aldehyde dehydrogenase 1 (ALDH1) phenotype to metastatic behavior and early tumor relapse in breast cancer is currently unclear.

Methods

147 randomly selected invasive ductal carcinoma samples were assayed for expression of ALDH1A1, NOTCH1, estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor (HER2), and association of the ALDH1A1 phenotype with clinic pathological features was further evaluated.

Results

ALDH1A1-positive cells were detected in 63.3% (93 of 147) of tumors. 80.0% (32 of 40) of tumors with strong ALDH1A1 staining displayed early recurrence, compared with 20.0% (8 of 40) of tumors negative for ALDH1A1 expression (P = 0.027). ALDH1A1 status was significantly correlated with strong malignant proliferative marker Ki67 staining (P = 0.001), and no significantly different expression of ALDH1A1 across the subtypes of ER, PR, and HER2 expression and triple negative features of tumor tissue. Multivariate regression analysis demonstrated that elevated ALDH1A1 expression is an independent predictor of recurrence-free survival and distant metastasis-free survival. Notably, breast cancer tissue strong for ALDH1A1 expression displayed weak NOTCH1 staining compared to ALDH1A1 weak tumor tissue (P = 0.002), and the relationship between ALDH1A1 and NOTCH1 mRNA positivity was significant (Pearson correlation - 0.337, P = 0.014; Spearman’s rho - 0.376, P = 0.006). Elevated NOTCH1 mRNA level (using a cut-off value based on the median ALDH1A1 2^-△△CT value) was associated with reduction of ALDH1A1 mRNA level (P = 0.001).

Conclusions

The ALDH1A1 phenotype is an independent predictor of early tumor relapse characteristic (specifically, incidence of early local recurrence and distant metastasis) of invasive ductal carcinoma. The NOTCH1 signaling pathway is possibly involved in the negative association of the ALDH1A1 phenotype with early malignant relapse in invasive ductal carcinoma.

Inflammatory breast cancer: New factors contribute to disease etiology: A review

Inflammatory breast cancer (IBC) is a highly metastatic and fatal form of breast cancer. In fact, IBC is characterized by specific morphological, phenotypic, and biological properties that distinguish it from non-IBC. The aggressive behavior of IBC being more common among young women and the low survival rate alarmed researchers to explore the disease biology. Despite the basic and translational studies needed to understand IBC disease biology and identify specific biomarkers, studies are limited by few available IBC cell lines, experimental models, and paucity of patient samples. Above all, in the last decade, researchers were able to identify new factors that may play a crucial role in IBC progression. Among identified factors are cytokines, chemokines, growth factors, and proteases. In addition, viral infection was also suggested to participate in the etiology of IBC disease. In this review, we present novel factors suggested by different studies to contribute to the etiology of IBC and the proposed new therapeutic insights.

A randomized phase II study of lapatinib + pazopanib versus lapatinib in patients with HER2+ inflammatory breast cancer

This multi-center Phase II study evaluated lapatinib, pazopanib, and the combination in patients with relapsed HER2+ inflammatory breast cancer. In Cohort 1, 76 patients were randomized 1:1 to receive lapatinib 1,500 mg + placebo or lapatinib 1,500 mg + pazopanib 800 mg (double-blind) once daily until disease progression, unacceptable toxicity, or death. Due to high-grade diarrhea observed with this dose combination in another study (VEG20007), Cohort 1 was closed. The protocol was amended such that an additional 88 patients (Cohort 2) were randomized in a 5:5:2 ratio to receive daily monotherapy lapatinib 1,500 mg, lapatinib 1,000 mg + pazopanib 400 mg, or monotherapy pazopanib 800 mg, respectively. The primary endpoint was overall response rate (ORR). Secondary endpoints included duration of response, progression-free survival (PFS), overall survival, and safety. In Cohort 1, ORR for the lapatinib (n = 38) and combination (n = 38) arms was 29 and 45 %, respectively; median PFS was 16.1 and 14.3 weeks, respectively. Grade ≥3 adverse events (AEs) were more frequent in the combination arm (71 %) than in the lapatinib arm (24 %). Dose reductions and interruptions due to AEs were also more frequent in the combination arm (45 and 53 %, respectively) than in the lapatinib monotherapy arm (0 and 11 %, respectively). In Cohort 2, ORR for patients treated with lapatinib (n = 36), lapatinib + pazopanib (n = 38), and pazopanib (n = 13) was 47, 58, and 31 %, respectively; median PFS was 16.0, 16.0, and 11.4 weeks, respectively. In the lapatinib, combination, and pazopanib therapy arms, grade ≥3 AEs were reported for 17, 50, and 46 % of patients, respectively, and the incidence of discontinuations due to AEs was 0, 24, and 23 %, respectively. The lapatinib-pazopanib combination was associated with a numerically higher ORR but no increase in PFS compared to lapatinib alone. The combination also had increased toxicity resulting in more dose reductions, modifications, and treatment delays. Activity with single-agent lapatinib was confirmed in this population.

Inflammatory and non-inflammatory breast cancer survival by socioeconomic position in the Surveillance, Epidemiology, and End Results database, 1990-2008

Although it has been previously reported that patients with inflammatory breast cancer (IBC) experience worse survival than patients with other breast cancer (BC) types, the socioeconomic and ethnic factors leading to this survival difference are not fully understood. The association between county-level percent of persons below the poverty level and BC-specific (BCS) survival for cases diagnosed from 1990 to 2008 in the Surveillance, Epidemiology, and End Results (SEER) database linked to census derived county attributes was examined. A sub-analysis of cases from 2000 to 2008 also examined BCS survival by an index combining percent below poverty and less than high school graduates as well as metropolitan versus non-metropolitan county of residence. The Kaplan-Meier estimator was used to construct survival curves by stage, inflammatory status, and county-level socioeconomic position (SEP). Stage and inflammatory status stratified proportional hazards models, adjusted for age, race/ethnicity, tumor and treatment characteristics were used to determine the hazard of BCS death by county-level SEP. Kaplan-Meier survival curves indicated IBC has worse survival than stage matched non-IBC, (stage III IBC median survival = 4.75 years vs. non-IBC = 13.4 years, p < 0.0001). Residing in a lower SEP, non-metro county significantly worsens BCS survival for non-IBC in multivariate proportional hazards models. African American cases appear to have worse survival than non-Hispanic Whites regardless of inflammatory status, stage, county-level SEP, tumor, or treatment characteristics. This is the first study to examine IBC survival by SEP in a nation-wide population-based tumor registry. As this analysis found generally poorer survival for IBC, regardless of SEP or race/ethnicity, it is important that interventions that help educate women on IBC symptoms target women in various SEP and race/ethnicity groups.

Alternate estrogen receptors promote invasion of inflammatory breast cancer cells via non-genomic signaling

Although Inflammatory Breast Cancer (IBC) is a rare and an aggressive type of locally advanced breast cancer with a generally worst prognosis, little work has been done in identifying the status of non-genomic signaling in the invasiveness of IBC. The present study was performed to explore the status of non-genomic signaling as affected by various estrogenic and anti-estrogenic agents in IBC cell lines SUM149 and SUM190. We have identified the presence of estrogen receptor α (ERα) variant, ERα36 in SUM149 and SUM190 cells. This variant as well as ERβ was present in a substantial concentration in IBC cells. The treatment with estradiol (E2), anti-estrogenic agents 4-hydroxytamoxifen and ICI 182780, ERβ specific ligand DPN and GPR30 agonist G1 led to a rapid activation of p-ERK1/2, suggesting the involvement of ERα36, ERβ and GPR30 in the non-genomic signaling pathway in these cells. We also found a substantial increase in the cell migration and invasiveness of SUM149 cells upon the treatment with these ligands. Both basal and ligand-induced migration and invasiveness of SUM149 cells were drastically reduced in the presence of MEK inhibitor U0126, implicating that the phosphorylation of ERK1/2 by MEK is involved in the observed motility and invasiveness of IBC cells. We also provide evidence for the upregulation of p-ERK1/2 through immunostaining in IBC patient samples. These findings suggest a role of non-genomic signaling through the activation of p-ERK1/2 in the hormonal dependence of IBC by a combination of estrogen receptors. These findings only explain the failure of traditional anti-estrogen therapies in ER-positive IBC which induces the non-genomic signaling, but also opens newer avenues for design of modified therapies targeting these estrogen receptors.

Triple-negative subtype predicts poor overall survival and high locoregional relapse in inflammatory breast cancer

BACKGROUND

Numerous studies have demonstrated that expression of estrogen/progesterone receptor (ER/PR) and human epidermal growth factor receptor (HER)-2 is important for predicting overall survival (OS), distant relapse (DR), and locoregional relapse (LRR) in early and advanced breast cancer patients. However, these findings have not been confirmed for inflammatory breast cancer (IBC), which has different biological features than non-IBC.

METHODS

We retrospectively analyzed the records of 316 women who presented to MD Anderson Cancer Center in 1989-2008 with newly diagnosed IBC without distant metastases. Most patients received neoadjuvant chemotherapy, mastectomy, and postmastectomy radiation. Patients were grouped according to receptor status: ER(+) (ER(+)/PR(+) and HER-2-; n = 105), ER(+)HER-2(+) (ER(+)/PR(+) and HER-2(+); n = 37), HER-2(+) (ER(-)/PR(-) and HER-2(+); n = 83), or triple-negative (TN) (ER(-)PR(-)HER-2(-); n = 91). Kaplan-Meier and Cox proportional hazards methods were used to assess LRR, DR, and OS rates and their associations with prognostic factors.

RESULTS

The median age was 50 years (range, 24-83 years). The median follow-up time and median OS time for all patients were both 33 months. The 5-year actuarial OS rates were 58.7% for the entire cohort, 69.7% for ER(+) patients, 73.5% for ER(+)HER-2(+) patients, 54.0% for HER=2(+) patients, and 42.7% for TN patients (p < .0001); 5-year LRR rates were 20.3%, 8.0%, 12.6%, 22.6%, and 38.6%, respectively, for the four subgroups (p < .0001); and 5-year DR rates were 45.5%, 28.8%, 50.1%, 52.1%, and 56.7%, respectively (p < .001). OS and LRR rates were worse for TN patients than for any other subgroup (p < .0001-.03).

CONCLUSIONS

TN disease is associated with worse OS, DR, and LRR outcomes in IBC patients, indicating the need for developing new locoregional and systemic treatment strategies for patients with this aggressive subtype.

Inhibition of cathepsin B activity attenuates extracellular matrix degradation and inflammatory breast cancer invasion

Introduction

Inflammatory breast cancer (IBC) is an aggressive, metastatic and highly angiogenic form of locally advanced breast cancer with a relatively poor three-year survival rate. Breast cancer invasion has been linked to proteolytic activity at the tumor cell surface. Here we explored a role for active cathepsin B on the cell surface in the invasiveness of IBC.

Methods

We examined expression of the cysteine protease cathepsin B and the serine protease urokinase plasminogen activator (uPA), its receptor uPAR and caveolin-1 in two IBC cell lines: SUM149 and SUM190. We utilized a live cell proteolysis assay to localize in real time the degradation of type IV collagen by IBC cells. IBC patient biopsies were examined for expression of cathepsin B and caveolin-1.

Results

Both cell lines expressed comparable levels of cathepsin B and uPA. In contrast, levels of caveolin-1 and uPAR were greater in SUM149 cells. We observed that uPA, uPAR and enzymatically active cathepsin B were colocalized in caveolae fractions isolated from SUM149 cells. Using a live-cell proteolysis assay, we demonstrated that both IBC cell lines degrade type IV collagen. The SUM149 cells exhibit predominantly pericellular proteolysis, consistent with localization of proteolytic pathway constitutents to caveolar membrane microdomains. A functional role for cathepsin B was confirmed by the ability of CA074, a cell impermeable and highly selective cathepsin B inhibitor, to significantly reduce pericellular proteolysis and invasion by SUM149 cells. A statistically significant co-expression of cathepsin B and caveolin-1 was found in IBC patient biopsies, thus validating our in vitro data.

Conclusion

Our study is the first to show that the proteolytic activity of cathepsin B and its co-expression with caveolin-1 contributes to the aggressiveness of IBC.

Association of inflammatory and noninflammatory breast cancer with socioeconomic characteristics in the Surveillance, Epidemiology, and End Results database, 2000-2007

BACKGROUND

Inflammatory breast cancer (IBC) is a rare and highly aggressive form of primary breast cancer. Little is known about the risk factors for IBC, specifically the association with socioeconomic position (SEP).

METHODS

The association between breast cancer type (IBC vs. non-IBC) with county-level SEP in the Surveillance, Epidemiology, and End Results database for cases diagnosed from 2000 to 2007 was examined. County-level SEP characteristics included metropolitan versus non-metropolitan residence, percentage below the poverty level, percentage less than high-school graduate, and an index combining the poverty and high-school variables. IBC and non-IBC age-adjusted incidence rates were calculated, stratified on SEP and race/ethnicity. The odds of IBC versus non-IBC given a particular SEP characteristic, adjusting for age and race/ethnicity, was examined through fitting of hierarchical logistic regression models (HLM).

RESULTS

Incidence rates for IBC generally increased as SEP decreased, whereas the opposite was found for non-IBC. HLM results showed that low SEP is associated with higher odds of IBC: highest (≥ 20%) versus lowest (<10%) persons below the poverty level [OR (95% confidence interval, CI) = 1.25 (1.09-1.43)]; highest (>28.76%) versus lowest (≤ 15.99%) persons less than high-school graduate [OR (95% CI) = 1.25 (1.10-1.42)]; and low SEP as measured by poverty-high school index versus high SEP [OR (95% CI)= 1.26 (1.11-1.44)].

CONCLUSION

Overall breast cancer has been found to be positively associated with SEP, whereas in this analysis, IBC was associated with decreasing SEP.

IMPACT

Studies focused on understanding the disparity in IBC incidence, as well as interventions to eliminate these differences are needed.

High-resolution comparative genomic hybridization of inflammatory breast cancer and identification of candidate genes

BACKGROUND

Inflammatory breast cancer (IBC) is an aggressive form of BC poorly defined at the molecular level. We compared the molecular portraits of 63 IBC and 134 non-IBC (nIBC) clinical samples.

METHODOLOGY/FINDINGS

Genomic imbalances of 49 IBCs and 124 nIBCs were determined using high-resolution array-comparative genomic hybridization, and mRNA expression profiles of 197 samples using whole-genome microarrays. Genomic profiles of IBCs were as heterogeneous as those of nIBCs, and globally relatively close. However, IBCs showed more frequent "complex" patterns and a higher percentage of genes with CNAs per sample. The number of altered regions was similar in both types, although some regions were altered more frequently and/or with higher amplitude in IBCs. Many genes were similarly altered in both types; however, more genes displayed recurrent amplifications in IBCs. The percentage of genes whose mRNA expression correlated with CNAs was similar in both types for the gained genes, but ∼7-fold lower in IBCs for the lost genes. Integrated analysis identified 24 potential candidate IBC-specific genes. Their combined expression accurately distinguished IBCs and nIBCS in an independent validation set, and retained an independent prognostic value in a series of 1,781 nIBCs, reinforcing the hypothesis for a link with IBC aggressiveness. Consistent with the hyperproliferative and invasive phenotype of IBC these genes are notably involved in protein translation, cell cycle, RNA processing and transcription, metabolism, and cell migration.

CONCLUSIONS

Our results suggest a higher genomic instability of IBC. We established the first repertory of DNA copy number alterations in this tumor, and provided a list of genes that may contribute to its aggressiveness and represent novel therapeutic targets.

[Expressions of Cyr61 and WISP-3 in non-small cell lung cancer and its clinical significance]

背景与目的

Cyr61是非小细胞肺癌（non-small cell lung cancer, NSCLC）生长过程中的一个肿瘤抑制基因，Cyr61与WISP-3同属于CCN基因家族，具有极其明显的序列同源性。本研究通过检测Cyr61和WISP-3在NSCLC组织中的表达，探讨其临床意义。

方法

应用免疫组化SP染色法检测54例NSCLC癌组织和癌旁正常肺组织中Cyr61和WISP-3的表达，并结合临床参数进行分析。

结果

在NSCLC癌组织中Cyr61表达水平低于癌旁正常肺组织（P < 0.001），WISP-3表达水平高于癌旁正常肺组织（P < 0.001）；NSCLC癌组织中Cyr61与WISP-3蛋白表达呈负相关（r=-0.395, P=0.003）；Cyr61的表达与肿瘤的组织学分化程度、病理类型、临床分期、家族史、吸烟史和淋巴结转移有关（P < 0.05）；WISP-3阳性表达率与肿瘤的组织学分化程度、临床分期和年龄有关（P < 0.05）。

结论

Cyr61和WISP-3可能是反映NSCLC进展、生物学行为、转移发生及预后的重要生物学标记物。

Inflammatory breast cancer: the disease, the biology, the treatment

Inflammatory breast cancer (IBC) is a rare and aggressive form of invasive breast cancer accounting for 2.5% of all breast cancer cases. It is characterized by rapid progression, local and distant metastases, younger age of onset, and lower overall survival compared with other breast cancers. Historically, IBC is a lethal disease with less than a 5% survival rate beyond 5 years when treated with surgery or radiation therapy. Because of its rarity, IBC is often misdiagnosed as mastitis or generalized dermatitis. This review examines IBC's unique clinical presentation, pathology, epidemiology, imaging, and biology and details current multidisciplinary management of the disease, which comprises systemic therapy, surgery, and radiation therapy.

Mesenchymal stem cells promote mammosphere formation and decrease E-cadherin in normal and malignant breast cells

INTRODUCTION

Normal and malignant breast tissue contains a rare population of multi-potent cells with the capacity to self-renew, referred to as stem cells, or tumor initiating cells (TIC). These cells can be enriched by growth as "mammospheres" in three-dimensional cultures.

OBJECTIVE

We tested the hypothesis that human bone-marrow derived mesenchymal stem cells (MSC), which are known to support tumor growth and metastasis, increase mammosphere formation.

RESULTS

We found that MSC increased human mammary epithelial cell (HMEC) mammosphere formation in a dose-dependent manner. A similar increase in sphere formation was seen in human inflammatory (SUM149) and non-inflammatory breast cancer cell lines (MCF-7) but not in primary inflammatory breast cancer cells (MDA-IBC-3). We determined that increased mammosphere formation can be mediated by secreted factors as MSC conditioned media from MSC spheroids significantly increased HMEC, MCF-7 and SUM149 mammosphere formation by 6.4 to 21-fold. Mammospheres grown in MSC conditioned media had lower levels of the cell adhesion protein, E-cadherin, and increased expression of N-cadherin in SUM149 and HMEC cells, characteristic of a pro-invasive mesenchymal phenotype. Co-injection with MSC in vivo resulted in a reduced latency time to develop detectable MCF-7 and MDA-IBC-3 tumors and increased the growth of MDA-IBC-3 tumors. Furthermore, E-cadherin expression was decreased in MDA-IBC-3 xenografts with co-injection of MSC.

CONCLUSIONS

MSC increase the efficiency of primary mammosphere formation in normal and malignant breast cells and decrease E-cadherin expression, a biologic event associated with breast cancer progression and resistance to therapy.

Gene expression profiling of inflammatory breast cancer

BACKGROUND

Inflammatory breast cancer (IBC) is a rare but aggressive form of breast cancer. Despite multimodality treatment, the long-term survival rate for patients with IBC has remained inferior at 50%. Until recently, IBC was understudied at the molecular level. Since 2004, new high-throughput molecular profiling technologies have been applied to clinical samples with the aim of identifying genes or pathways potentially involved in disease development that may represent new, clinically relevant targets.

METHODS

The authors conducted gene expression profiling studies of IBC clinical samples and investigated issues that may be addressed in the future to allow the "omics" approach to reach its full potential in IBC.

RESULTS

Starting in December 2004, 6 research groups compared the expression profiles of IBC samples and non-IBC samples. The series of samples were small (37 IBCs for the largest study) and heterogeneous (various tumor selection criteria and technologic platforms were used). The results indicated the feasibility of messenger RNA expression profiling from IBC biopsies, and they demonstrated the great transcriptional heterogeneity of IBC and the existence of molecular subtypes similar to non-IBC that more frequently were basal and positive for ERBB2. Supervised analyses demonstrated differences in gene expression levels between the IBC and non-IBC variable across studies with sometimes no or very subtle differences and, to date, no gene overlap across the reported signatures. No signature predictive of therapeutic response or clinical outcome has been reliably identified or validated.

CONCLUSIONS

Because of the great heterogeneity of IBC, future studies will have to include larger series of IBC samples that are selected using homogeneous criteria. This calls for urgent international collaborations.

Differential regulation of the aggressive phenotype of inflammatory breast cancer cells by prostanoid receptors EP3 and EP4

BACKGROUND

Although inflammatory breast cancer (IBC) is recognized as the most lethal variant of locally advanced breast cancer, few molecular signatures of IBC have been identified that can be used as targets to develop therapeutics that effectively inhibit the aggressive phenotype displayed by IBC tumors.

METHODS

Real-time polymerase chain reaction analysis, Western blot analysis, modified Boyden chamber invasion assays, vasculogenic mimicry (VM) assays, and gelatin zymography were used in the current studies. Agonists and antagonists of the prostanoid receptors EP3 and EP4 and of EP4 short-hairpin RNA (shRNA) knockdown approaches were used as tools to assess the role of prostanoid receptors EP3 and EP4 in the regulation of specific biologic activities of IBC cells.

RESULTS

The current studies revealed that the IBC breast cancer cell lines SUM149 and SUM190 express high levels of cyclooxygenase-2 messenger RNA and protein, produce abundant levels of prostaglandin E(2), and produce both EP3 and EP4 receptor proteins. Studies using the EP4 antagonist GW627368X and shRNA molecular knockdown approaches revealed a role for EP4 in regulating invasion of IBC cells. EP3, but not EP4, regulated the ability of SUM149 cells to undergo VM, which is the ability to form capillary-like structures, a characteristic exhibited by very aggressive tumor types. Inhibition of VM by sulprostone was associated with an inhibition of matrix metalloprotease-2 (MMP-2) enzyme activity.

CONCLUSIONS

The prostanoid receptors EP3 and EP4 differentially regulate activities exhibited by IBC cells that have been associated with the aggressive phenotype of this lethal variant of breast cancer. Whereas EP4 regulates invasion, EP3 regulates VM and the associated increased MMP-2 enzyme activity.

Inflammatory breast cancer: novel preoperative therapies

The treatment of inflammatory breast cancer (IBC) has been hampered by the diagnostic rarity of the disease and its consequent inclusion in clinical trials of preoperative treatment for the more indolent locally advanced breast cancer (LABC). Patients with IBC have a 2-fold greater probability of dying of their disease compared with patients diagnosed with LABC. The aggressive clinical portrait of IBC supports the recent investigative focus on determining molecular changes specific to IBC and developing novel systemic therapies that will favorably affect its poor disease prognosis. A significant amount of laboratory research has been involved in defining a specific "inflammatory signature" for IBC, denoting molecular changes consistently found in IBC. This work has involved human IBC tissue and cell lines and has demonstrated overexpression of several molecules governing metastatic dissemination, such as overexpression of E-cadherin concurrent with a dysfunctional mucin 1. An increased prevalence of mutant TP53, overexpression of RhoC, and vascular endothelial growth factor-A has been found to contribute to the dominant influence of angiogenesis in this disease. A greater understanding of the molecular mechanisms governing the pathophysiology of IBC has led to the development and clinical application of novel targeting agents for preoperative therapy. This study reviews the advances in molecular understanding of IBC and focuses on the efficacy of therapies that target the epidermal growth factor pathway and angiogenesis as well as early investigational therapies involving RhoC and TP53.

Biology and management of inflammatory breast cancer

Inflammatory breast cancer is an aggressive subtype of a locally advanced breast cancer that is thought to account for approximately 1-5% of all newly diagnosed breast cancers diagnosed in the USA. Historically, IBC was considered to be a uniformly fatal disease with less than 5% of patients surviving past 5 years. With the advent of a multidisciplinary approach to management, survival outcomes have improved with 5-year survival rates of over 40% being reported. Research efforts are now focused on trying to better understand the epidemiological and molecular characteristics of this disease to further improve survival. Two genes, Rhoc GTPase and WISP3, have been identified that have been found to be concordantly altered in the majority of inflammatory breast cancer tumors and may serve as potential targets for future therapeutic agents. The purpose of this review is to summarize the latest epidemiological and molecular characteristics of IBC, describe the difficulties encountered in trying to clinically diagnose this entity, highlight the importance of a multidisciplinary approach and present some of the latest data on the management of this disease.

Pomegranate fruit extract impairs invasion and motility in human breast cancer

PURPOSE

Pomegranate fruit extracts (PFEs) possess polyphenolic and other compounds with antiproliferative, pro-apoptotic and anti-inflammatory effects in prostate, lung, and other cancers. Because nuclear transcription factor-kB (NF-kB) is known to regulate cell survival, proliferation, tumorigenesis, and inflammation, it was postulated that PFEs may exert anticancer effects at least in part by modulating NF-kB activity.

EXPERIMENTAL DESIGN

The authors investigated the effect of a novel, defined PFE consisting of both fermented juice and seed oil on the NF-kB pathway, which is constitutively active in aggressive breast cancer cell lines. The effects of the PFE on NF-kB-regulated cellular processes such as cell survival, proliferation, and invasion were also examined.

RESULTS

Analytical characterization of the bioactive components of the PFE revealed active constituents, mainly ellagitannins and phenolic acids in the aqueous PFE and conjugated octadecatrienoic acids in the lipid PFE derived from seeds.The aqueous PFE dose-dependently inhibited NF-kB-dependent reporter gene expression associated with proliferation, invasion, and motility in aggressive breast cancer phenotypes while decreasing RhoC and RhoA protein expression.

CONCLUSION

Inhibition of motility and invasion by PFEs, coincident with suppressed RhoC and RhoA protein expression, suggests a role for these defined extracts in lowering the metastatic potential of aggressive breast cancer species.

RhoC expression level is correlated with the clinicopathological characteristics of ovarian cancer and the expression levels of ROCK-I, VEGF, and MMP9

OBJECTIVE

To determine the clinicopathological significance of RhoC expression in human ovarian cancer and its effect on the expression of vascular endothelial growth factor (VEGF), Rho-associated coiled-coil-forming kinase (ROCK), and metal matrix proteinases (MMPs).

METHODS

Tissue samples from normal ovaries, benign ovarian tumors, and epithelial ovarian cancer were collected. The mRNA and protein expression levels of RhoC, ROCK-I, VEGF, and MMP9 were assessed using reverse-transcriptase polymerase chain reaction (RT-PCR) and Western blot, and compared to the clinicopathological characteristics of the sample of origin using the Pearson method of correlation analysis. Small interfering RNA (siRNA) was also used to target RhoC expression in the OVCAR3 and CaOV3 ovarian cancer cell lines, after which cell invasion and migration assays were performed, and the expression of ROCK-I, VEGF, and MMP9 was evaluated.

RESULTS

The expression levels of RhoC, ROCK-I, VEGF, and MMP9 mRNA and protein were significantly higher in ovarian cancer, showing a correlation with clinical stage but not histological type. RhoC expression was positively correlated with ROCK-I, VEGF, and MMP9 expression. Decreased RhoC expression in siRNA-targeted cells inhibited their ability to invade and migrate, as well as inhibiting ROCK-I, VEGF, and MMP9 expression.

CONCLUSION

The expression level of RhoC is correlated to clinical stage and vascularization in ovarian cancer.

Aldehyde dehydrogenase 1-positive cancer stem cells mediate metastasis and poor clinical outcome in inflammatory breast cancer

PURPOSE

To examine the role of cancer stem cells (CSC) in mediating metastasis in inflammatory breast cancer (IBC) and the association of these cells with patient outcome in this aggressive type of breast cancer.

EXPERIMENTAL DESIGN

CSCs were isolated from SUM149 and MARY-X, an IBC cell line and primary xenograft, by virtue of increased aldehyde dehydrogenase (ALDH) activity as assessed by the ALDEFLUOR assay. Invasion and metastasis of CSC populations were assessed by in vitro and mouse xenograft assays. Expression of ALDH1 was determined on a retrospective series of 109 IBC patients and this was correlated with histoclinical data. All statistical tests were two sided. Log-rank tests using Kaplan-Meier analysis were used to determine the correlation of ALDH1 expression with development of metastasis and patient outcome.

RESULTS

Both in vitro and xenograft assays showed that invasion and metastasis in IBC are mediated by a cellular component that displays ALDH activity. Furthermore, expression of ALDH1 in IBC was an independent predictive factor for early metastasis and decreased survival in this patient population.

CONCLUSIONS

These results suggest that the metastatic, aggressive behavior of IBC may be mediated by a CSC component that displays ALDH enzymatic activity. ALDH1 expression represents the first independent prognostic marker to predict metastasis and poor patient outcome in IBC. The results illustrate how stem cell research can translate into clinical practice in the IBC field.

Breast cancer molecular subtypes in patients with locally advanced disease: impact on prognosis, patterns of recurrence, and response to therapy

Gene expression profiling has led to the discovery of 4 distinct molecular subtypes of breast cancer: luminal A, luminal B, basal like, and HER2 enriched. Investigation of these subtypes in women with breast cancer has given insight into the heterogeneous biology and outcomes in patients with locally advanced disease. These subtypes have been found to be predictors for survival, response to systemic therapy, and locoregional recurrence. This review discusses the biology of locally advanced breast cancer and the available data on how molecular subtype may provide information regarding response to treatment and prognosis of women with locally advanced breast cancer.

RhoC expression and head and neck cancer metastasis

RhoC protein, a known marker of metastases in aggressive breast cancers and melanoma, has also been found to be overexpressed in certain head and neck cancers, thus we investigated the correlation between RhoC expression and the metastatic behavior of head and neck squamous cell carcinoma. Selective inhibition of RhoC expression was achieved using lentiviral small hairpin RNA (shRNA) transduced and tracked with green fluorescent protein to achieve 70% to 80% RhoC inhibition. Fluorescence microscopy of the RhoC knockdown stable clones showed strong green fluorescence in the majority of cells, signifying a high efficiency of transduction. Importantly, quantitative real-time PCR showed no significant decrease in the mRNA expression levels of other members of the Ras superfamily. Cell motility and invasion were markedly diminished in RhoC-depleted cell lines as compared with control transduced lines. H&E staining of lung tissue obtained from severe combined immunodeficiency mice, which had been implanted with RhoC knockdown cells, showed a marked decrease in lung metastasis and inflammation of the blood vessels. The cultured lung tissue showed a significant decrease in cell growth in mice implanted with RhoC-depleted cell lines as compared with shRNA-scrambled sequence control lines. Microscopic studies of CD31 expression revealed substantial quantitative and qualitative differences in the primary tumor microvessel density as compared with parental and shRNA-scrambled controls. This study is the first of its kind to establish the involvement of RhoC specifically in head and neck metastasis. These findings suggest that RhoC warrants further investigation to delineate its robustness as a novel potentially therapeutic target.

The emerging role of CCN6 in breast cancer invasion

The CCN family of matricellular proteins is essential for cell communication and mediation of epithelial stromal cross-talks with roles in development and cancer. In particular, loss of CCN6 messenger RNA expression has been recognized in highly aggressive breast cancers, especially in inflammatory breast cancer and breast cancers with axillary lymph node metastasis. Recent findings can better explain the relevance of CCN6's reduced expression on human invasive breast carcinomas. CCN6 has been shown to play a role in the process of epithelial to mesenchymal transition (EMT), which converts epithelial cells into migratory mesenchymal-like cells with invasive abilities. Although the mechanism by which CCN6 promotes EMT and invasion has not been fully elucidated, current data suggest that it involves the recruitment of the transcriptional regulators Snai1 and ZEB1 to the E-cadherin promoter.

Molecular targets for treatment of inflammatory breast cancer

Despite progress in combined-modality treatment with chemotherapy, surgery, and radiation therapy, the long-term outcome for patients with inflammatory breast cancer (IBC) remains poor. Therapies that target vasculolymphatic processes--angiogenesis, lymphangiogenesis, and vasculogenesis--have shown potential in the treatment for IBC, as represented by bevacizumab. Although the therapeutic effect of targeting lymphangiogenesis and vasculogenesis requires further investigation, targeting of angiogenesis has potential, not only through true antiangiogenic effects, but also through antitumor effects in concert with other pathways. Therapies that target cell proliferation pathways are the most promising targeted therapies for IBC. In particular, therapies that target human epidermal growth factor receptor 2 (for example, trastuzumab and lapatinib) have performed well in the clinical setting, leading to improved outcomes for patients with IBC. Metastatic pathways could have a unique, key role in the aggressiveness of the IBC phenotype. Further extensive work on the unique molecular characteristics of IBC is essential to ensure improved outcomes for patients with this disease. In this Review we discuss three pathways--vasculolymphatic, cell proliferation and metastatic--that could represent important targets in the treatment of IBC.

Myosin-interacting guanine exchange factor (MyoGEF) regulates the invasion activity of MDA-MB-231 breast cancer cells through activation of RhoA and RhoC

The small GTPase proteins RhoA and RhoC are essential for tumor invasion and/or metastasis in breast carcinomas. However, it is poorly understood how RhoA and RhoC are activated in breast cancer cells. Here we describe the role of MyoGEF in regulating RhoA and RhoC activation as well as cell polarity and invasion in an invasive breast cancer cell line MDA-MB-231. RNA-interference (RNAi)-mediated depletion of MyoGEF in MDA-MB-231 cells not only suppresses the activation of RhoA and RhoC, but also decreases cell polarity and invasion activity. The dominant negative mutants of RhoA and RhoC, but not Rac1 and Cdc42, dramatically decrease actin polymerization induced by MyoGEF. In addition, MyoGEF colocalizes with nonmuscle myosin IIA (NMIIA) to the front of migrating cells, and depletion of NMIIA by RNAi disrupts the polarized localization of MyoGEF at the cell leading edge, suggesting a role for NMIIA in regulating MyoGEF localization and function. Moreover, MyoGEF protein levels significantly increase in infiltrating ductal carcinomas as well as in invasive breast cancer cell lines. Taken together, our results suggest that MyoGEF cooperates with NMIIA to regulate the polarity and invasion activity of breast cancer cells through activation of RhoA and RhoC.

Normal growth and development in mice over-expressing the CCN family member WISP3

Loss-of-function mutations in the gene WISP3 cause the autosomal recessive human skeletal disease Progressive Pseudorheumatoid Dysplasia, whereas mice with knockout mutations of Wisp3 have no phenotype. The lack of a phenotype in the Wisp3 knockout mice has constrained studies of the protein’s in vivo function. Over-expression experiments in zebrafish indicated that WISP3 may function as a BMP and Wnt signaling modulator. To determine whether these biologic activities are retained in mice, we created two strains of transgenic mice that over-express WISP3 in a broad array of tissues. Despite strong and persistent protein over-expression, the transgenic mice remained phenotypically indistinguishable from their non-transgenic littermates. Surprisingly, WISP3 contained in conditioned medium recovered from transgenic mouse primary kidney cell cultures was able to bind BMP and to inhibit BMP signaling in vitro. Factors that account for the difference between the in vitro and in vivo activities of WISP3 remain unknown. At present, the mouse remains a challenging model organism in which to explore the biologic function of WISP3.

Summary of article. Transgenic mice that broadly over-express WISP3 were created to search for in vivo biologic activities, since mice that lack WISP3 were normal. Surprisingly, transgenic mice were also phenotypically indistinguishable from wild-type animals. The mouse is a challenging model organism in which to explore the biologic function of WISP3.