RAGE inhibitor TTP488 (Azeliragon) suppresses metastasis in triple-negative breast cancer.

Triple-negative breast cancer (TNBC) is a highly aggressive and metastatic cancer subtype, which is generally untreatable once it metastasizes. We hypothesized that interfering with the Receptor for Advanced Glycation End-products (RAGE) signaling with the small molecule RAGE inhibitors (TTP488/Azeliragon and FPS-ZM1) would impair TNBC metastasis and impair fundamental mechanisms underlying tumor progression and metastasis. Both TTP488 and FPS-ZM1 impaired spontaneous and experimental metastasis of TNBC models, with TTP488 reducing metastasis to a greater degree than FPS-ZM1. Transcriptomic analysis of primary xenograft tumor and metastatic tissue revealed high concordance in gene and protein changes with both drugs, with TTP488 showing greater potency against metastatic driver pathways. Phenotypic validation of transcriptomic analysis by functional cell assays revealed that RAGE inhibition impaired TNBC cell adhesion to multiple extracellular matrix proteins (including collagens, laminins, and fibronectin), migration, and invasion. Neither RAGE inhibitor impaired cellular viability, proliferation, or cell cycle in vitro. Proteomic analysis of serum from tumor-bearing mice revealed RAGE inhibition affected metastatic driver mechanisms, including multiple cytokines and growth factors. Further mechanistic studies by phospho-proteomic analysis of tumors revealed RAGE inhibition led to decreased signaling through critical BC metastatic driver mechanisms, including Pyk2, STAT3, and Akt. These results show that TTP488 impairs metastasis of TNBC and further clarifies the signaling and cellular mechanisms through which RAGE mediates metastasis. Importantly, as TTP488 displays a favorable safety profile in human studies, our study provides the rationale for evaluating TTP488 in clinical trials to treat or prevent metastatic TNBC.

Propagated Circulating Tumor Cells Uncover the Potential Role of NFκB, EMT, and TGFß Signaling Pathways and COP1 in Metastasis.

Circulating tumor cells (CTCs), a population of cancer cells that represent the seeds of metastatic nodules, are a promising model system for studying metastasis. However, the expansion of patient-derived CTCs ex vivo is challenging and dependent on the collection of high numbers of CTCs, which are ultra-rare. Here we report the development of a combined CTC and cultured CTC-derived xenograft (CDX) platform for expanding and studying patient-derived CTCs from metastatic colon, lung, and pancreatic cancers. The propagated CTCs yielded a highly aggressive population of cells that could be used to routinely and robustly establish primary tumors and metastatic lesions in CDXs. Differential gene analysis of the resultant CTC models emphasized a role for NF-κB, EMT, and TGFß signaling as pan-cancer signaling pathways involved in metastasis. Furthermore, metastatic CTCs were identified through a prospective five-gene signature (BCAR1, COL1A1, IGSF3, RRAD, and TFPI2). Whole-exome sequencing of CDX models and metastases further identified mutations in constitutive photomorphogenesis protein 1 (COP1) as a potential driver of metastasis. These findings illustrate the utility of the combined patient-derived CTC model and provide a glimpse of the promise of CTCs in identifying drivers of cancer metastasis.

Relationships Between Serum Cortisol, RAGE-Associated s100A8/A9 Levels, and Self-Reported Cancer-Related Distress in Women With Nonmetastatic Breast Cancer.

OBJECTIVE: Elevated inflammation and psychological distress in patients with breast cancer (BCa) have been related to poorer health outcomes. Regulation of the hypothalamic-pituitary-adrenal axis and signaling of the receptor for advanced glycation end products (RAGE) are important in the inflammatory response and have been associated with increased stress and poorer health outcomes in patients with cancer. This study examined relationships among circulating cortisol, a measure of hypothalamic-pituitary-adrenal axis activity and physiological stress; s100A8/A9, a RAGE ligand and emerging cancer-related biological measure; and self-reported cancer-related distress. METHODS: Patients with BCa ( N = 183, stages 0-IIIb) were recruited 2 to 10 weeks after surgery but before receiving adjuvant therapies. Participants provided blood samples, from which serum cortisol and s100A8/A9 levels were determined, and completed a psychosocial questionnaire. Regression analyses, adjusting for age, cancer stage, time since surgery, race, and menopausal status, were conducted examining the relationships between cortisol, s100A8/A9, and cancer-related distress (Impact of Event Scale [IES]-Revised). RESULTS: Cortisol and s100A8/A9 levels were positively related ( ß = 0.218, t (112) = 2.332, p = .021), although the overall model was not significant. Cortisol levels were also positively associated with IES-Intrusions ( ß = 0.192, t (163) = 2.659, p = .009) and IES-Hyperarousal subscale scores ( ß = 0.171, t (163) = 2.304, p = .022). CONCLUSIONS: Patients with higher cortisol levels also reported higher s100A8/A9 levels and more cancer-related distress. The relationship between cortisol and s100A8/A9 supports a link between the stress response and proinflammatory physiological processes known to predict a greater metastatic risk in BCa. Stress processes implicated in cancer biology are complex, and replication and extension of these initial findings are important.

The role of estrogen receptor signaling in suppressing the immune response to cancer.

Immune checkpoint blockade (ICB) therapies are standard of care for the treatment of many solid tumors. While some patients with cancer experience exceptional and long-term responses, intrinsic and acquired mechanisms of resistance limit the clinical efficacy of ICBs. In addition, ICBs can elicit life-threatening side effects. Alternative options that can increase ICB responses without added toxicities are needed. In this issue of the JCI, Chakraborty et al. explored the role of estrogen receptor α (ERα) in modulating ICB activity. Using transcriptomics and preclinical melanoma models, the authors show that ERα signaling in tumor-associated macrophages contributed to an immune-suppressive state within the tumor microenvironment (TME) by promoting CD8+ T cell dysfunction and exhaustion. Further, in murine melanoma models, the addition of fulvestrant, a selective estrogen receptor downregulator (SERD) approved for the treatment of breast cancer, enhanced the antitumor effects of ICB. These results provide a rationale for human trials to test the combination of antiestrogens with ICBs.

Applying a Life Course Biological Age Framework to Improving the Care of Individuals With Adult Cancers: Review and Research Recommendations.

IMPORTANCE: The practice of oncology will increasingly involve the care of a growing population of individuals with midlife and late-life cancers. Managing cancer in these individuals is complex, based on differences in biological age at diagnosis. Biological age is a measure of accumulated life course damage to biological systems, loss of reserve, and vulnerability to functional deterioration and death. Biological age is important because it affects the ability to manage the rigors of cancer therapy, survivors' function, and cancer progression. However, biological age is not always clinically apparent. This review presents a conceptual framework of life course biological aging, summarizes candidate measures, and describes a research agenda to facilitate clinical translation to oncology practice. OBSERVATIONS: Midlife and late-life cancers are chronic diseases that may arise from cumulative patterns of biological aging occurring over the life course. Before diagnosis, each new patient was on a distinct course of biological aging related to past exposures, life experiences, genetics, and noncancer chronic disease. Cancer and its treatments may also be associated with biological aging. Several measures of biological age, including p16INK4a, epigenetic age, telomere length, and inflammatory and body composition markers, have been used in oncology research. One or more of these measures may be useful in cancer care, either alone or in combination with clinical history and geriatric assessments. However, further research will be needed before biological age assessment can be recommended in routine practice, including determination of situations in which knowledge about biological age would change treatment, ascertaining whether treatment effects on biological aging are short-lived or persistent, and testing interventions to modify biological age, decrease treatment toxic effects, and maintain functional abilities. CONCLUSIONS AND RELEVANCE: Understanding differences in biological aging could ultimately allow clinicians to better personalize treatment and supportive care, develop tailored survivorship care plans, and prescribe preventive or ameliorative therapies and behaviors informed by aging mechanisms.

RAC1 plays an essential role in estrogen receptor alpha function in breast cancer cells.

The activity of Rho family GTPase protein, RAC1, which plays important normal physiological functions, is dysregulated in multiple cancers. RAC1 is expressed in both estrogen receptor alpha (ER)-positive and ER-negative breast cancer (BC) cells. However, ER-positive BC is more sensitive to RAC1 inhibition. We have determined that reducing RAC1 activity, using siRNA or EHT 1864 (a small molecule Rac inhibitor), leads to rapid ER protein degradation. RAC1 interacts with ER within the ER complex and RAC1 localizes to chromatin binding sites for ER upon estrogen treatment. RAC1 activity is important for RNA Pol II function at both promoters and enhancers of ER target genes and ER-regulated gene transcription is blocked by EHT 1864, in a dose-dependent manner. Having identified that RAC1 is an essential ER cofactor for ER protein stability and ER transcriptional activity, we report that RAC1 inhibition could be an effective therapeutic approach for ER-positive BC.

Heterotypic clustering of circulating tumor cells and circulating cancer-associated fibroblasts facilitates breast cancer metastasis.

BACKGROUND: Cancer-associated fibroblasts (CAFs) are recruited to the tumor microenvironment (TME) and are critical drivers of breast cancer (BC) malignancy. Circulating tumor cells (CTCs) travel through hematogenous routes to establish metastases. CTCs circulate both individually and, more rarely, in clusters with other cell types. Clusters of CTCs have higher metastatic potential than single CTCs. Previously, we identified circulating CAFs (cCAFs) in patients with BC and found that while healthy donors had no CTCs or cCAFs, both were present in most Stage IV patients. cCAFs circulate individually, as cCAF-cCAF homotypic clusters, and in heterotypic clusters with CTCs. METHODS: In this study, we evaluate CTCs, cCAFs, and heterotypic cCAF-CTC clusters in patients with stage I-IV BC. We evaluate the association of heterotypic clusters with BC disease progression and metastasis in a spontaneous mouse model. Using previously established primary BC and CAF cell lines, we examine the metastatic propensity of heterotypic cCAF-CTC clusters in orthotopic and tail vein xenograft mouse models of BC. Using an in vitro clustering assay, we determine factors that may be involved in clustering between CAF and BC cells. RESULTS: We report that the dissemination of CTCs, cCAFs, and clusters is an early event in BC progression, and we find these clusters in all clinical stages of BC. Furthermore, cCAFs-CTC heterotypic clusters have a higher metastatic potential than homotypic CTC clusters in vivo. We also demonstrate that the adhesion and stemness marker CD44, found on a subset of CTCs and CAF cells, is  involved in heterotypic clustering of these cells. CONCLUSION: We identify a novel subset of circulating tumor cell clusters that are enriched with stromal CAF cells in BC patient blood and preclinical mouse models of BC metastasis. Our data suggest that clustering of CTCs with cCAFs augments their metastatic potential and that CD44 might be an important mediator of heterotypic clustering of cCAFs and BC cells.

Hormone-Dependent Prostate Cancers are Dependent on Rac Signaling for Growth and Survival.

Prostate cancer remains a common cause of cancer mortality in men. Initially, cancers are dependent of androgens for growth and survival. First line therapies reduce levels of circulating androgens or target the androgen receptor (AR) directly. Although most patients show durable responses, many patients eventually progress to castration-resistant prostate cancer (CRPC) creating a need for alternative treatment options. The Rac1 signaling pathway has previously been implicated as a driver of cancer initiation and disease progression. We investigated the role of HACE1, the E3 ubiquitin ligase for Rac1, in prostate cancer and found that HACE1 is commonly lost resulting in hyperactive Rac signaling leading to enhanced cellular proliferation, motility and viability. Importantly, we show that a Rac inhibitor can attenuate the growth and survival of prostate cancer cells. Rac signaling was also found to be critical in prostate cancers that express the AR. Rac inhibition in androgen dependent cells resulted in reduction of AR target gene expression suggesting that targeting Rac1 may be an alternative method for blocking the AR signaling axis. Finally, when used in combination with AR antagonists, Rac inhibition enhanced the suppression of AR target gene expression. Therefore, targeting Rac in prostate cancer has the potential to enhance the efficacy of approved AR therapies.

Effects of brief stress management interventions on distress and leukocyte nuclear factor kappa B expression during primary treatment for breast cancer: A randomized trial.

BACKGROUND: A randomized controlled trial (RCT) of 5-week stress management interventions teaching cognitive behavioral therapy (CBT) or relaxation training (RT) techniques showed decreases in stress and serum inflammatory markers over 12 months in women undergoing treatment for breast cancer (BCa). To understand the molecular mechanisms involved, we examined the effects of these interventions on the transcription factor NF-κB DNA binding activity in leukocytes in parallel with circulating inflammatory markers, stress management skill efficacy and multiple distress indicators. METHODS: This is a secondary analysis using blood samples of 51 BCa patients (Stage 0-III) with high cancer-specific distress selected from a completed RCT (NCT02103387). Women were randomized to one of three conditions, CBT, RT or health education control (HE). Blood samples and self-reported distress measures (Affects Balance Scale-Negative Affect [ABS-NA], Impact of Events Scale-hyperarousal [IES-H] and intrusive thoughts [IES-I]) were collected at baseline (T0) and 12-month follow-up (T2). Self-reported distress measures and perceived stress management skills (PSMS) were also measured immediately post-intervention (baseline + 2 months: T1). Repeated measures analyses compared changes in distress and NF-κB expression among conditions, controlling for age, stage of cancer, days from surgery to baseline, and receipt of chemotherapy and radiation. Regression analyses related T0 to T2 change in NF-κB expression with T0 to T1 changes in self-reported PSMS and distress measures. Exploratory regression analyses also associated change in NF-κB expression with change in serum cytokines (IL-1ß, IL-6 and TNF-α); and s100A8/A9, a circulating inflammatory marker important in breast cancer progression. RESULTS: There was a significant condition (CBT/RT, HE)xtime (T0, T2) effect on NF-κB, F(1, 39)= 5.267, p = 0.036, wherein NF-κB expression significantly increased over time for HE but did not change for RT or CBT. Greater increases in PSMS from T0 to T1 were associated with less increase in NF-κB expression over 12 months (ß = -0.426, t(36) = -2.637, p = 0.048). We found that women assigned to active intervention (CBT/RT) had significant decreases in ABS-NA (F(1, 40)= 6.537, p = 0.028) and IES-I (F(1, 40)= 4.391, p = 0.043) from T0 to T1 compared to women assigned to HE, who showed no change over time (p's > 0.10). For women assigned to CBT or RT, lower NF-κB expression at T2 was related to less ABS-NA, IES-H, and IES-I, all p's < 0.05, although T0-T1 change in distress was not related to T0-T2 change in NF-κB expression for those in an active intervention. CONCLUSIONS: Brief CBT or RT stress management interventions can mitigate increases in pro-inflammatory leukocyte NF-κB binding over 12 months of primary treatment in highly distressed BCa patients. These effects are likely brought about by improved stress management skills.

Spindle assembly checkpoint gene BUB1B is essential in breast cancer cell survival.

PURPOSE: The study aimed to investigate the role of spindle assembly checkpoint (SAC) in cancer cells with compromised genomic integrity. Chromosomal instability (CIN) gives cancer cells an adaptive advantage. However, maintaining the balance of this instability is crucial for the survival of cancer cells as it could lead them to the mitotic catastrophe. Therefore, cancer cells adapt to the detrimental effects of CIN. We hypothesized that changes in SAC might be one such adaptation mechanism. The focus of the study was BUB1B, an integral part of the checkpoint. METHODS: Clinical datasets were analyzed to compare expression levels of SAC genes in normal tissue vs. breast carcinoma. The effects of the reduction of BUB1B expression was examined utilizing RNA interference method with siRNAs. In vitro viability, clonogenicity, apoptosis, and SAC activity levels of a variety of breast cancer (BrCa) cell lines, as well as in vivo tumorigenicity of the triple-negative breast cancer (TNBC) cell line MDA-MB-468, were tested. Additionally, the chromosomal stability of these cells was tested by immunofluorescence staining and flow cytometry. RESULTS: In clinical breast cancer datasets, SAC genes were elevated in BrCa with BUB1B having the highest fold change. BUB1B overexpression was associated with a decreased probability of overall survival. The knockdown of BUB1B resulted in reduced viability and clonogenicity in BrCa cell lines and a significant increase in apoptosis and cell death. However, the viability and apoptosis levels of the normal breast epithelial cell line, MCF12A, were not affected. BUB1B knockdown also impaired chromosome alignment and resulted in acute chromosomal abnormalities. We also showed that BUB1B knockdown on the MDA-MB-468 cell line decreases tumor growth in mice. CONCLUSIONS: A functional spindle assembly checkpoint is essential for the survival of BrCa cells. BUB1B is a critical factor in SAC, and therefore breast cancer cell survival. Impairment of BUB1B has damaging effects on cancer cell viability and tumorigenicity, especially on the more aggressive variants of BrCa.

The Major Pre- and Postmenopausal Estrogens Play Opposing Roles in Obesity-Driven Mammary Inflammation and Breast Cancer Development.

Many inflammation-associated diseases, including cancers, increase in women after menopause and with obesity. In contrast to anti-inflammatory actions of 17ß-estradiol, we find estrone, which dominates after menopause, is pro-inflammatory. In human mammary adipocytes, cytokine expression increases with obesity, menopause, and cancer. Adipocyte:cancer cell interaction stimulates estrone- and NFκB-dependent pro-inflammatory cytokine upregulation. Estrone- and 17ß-estradiol-driven transcriptomes differ. Estrone:ERα stimulates NFκB-mediated cytokine gene induction; 17ß-estradiol opposes this. In obese mice, estrone increases and 17ß-estradiol relieves inflammation. Estrone drives more rapid ER+ breast cancer growth in vivo. HSD17B14, which converts 17ß-estradiol to estrone, associates with poor ER+ breast cancer outcome. Estrone and HSD17B14 upregulate inflammation, ALDH1 activity, and tumorspheres, while 17ß-estradiol and HSD17B14 knockdown oppose these. Finally, a high intratumor estrone:17ß-estradiol ratio increases tumor-initiating stem cells and ER+ cancer growth in vivo. These findings help explain why postmenopausal ER+ breast cancer increases with obesity, and offer new strategies for prevention and therapy.

Rac Signaling Drives Clear Cell Renal Carcinoma Tumor Growth by Priming the Tumor Microenvironment for an Angiogenic Switch.

Clear cell renal cell carcinoma (ccRCC) remains a common cause of cancer mortality. Better understanding of ccRCC molecular drivers resulted in the development of antiangiogenic therapies that block the blood vessels that supply tumors with nutrients for growth and metastasis. Unfortunately, most ccRCC patients eventually become resistant to initial treatments, creating a need for alternative treatment options. We investigated the role of the small GTPase Rac1 in ccRCC. Analysis of ccRCC clinical samples indicates that Rac signaling drives disease progression and predicts patients with poorer outcomes. Investigation of Rac1 identifies multiple roles for Rac1 in the pathogenesis of ccRCC. Rac1 is overexpressed in RCC cell lines and drives proliferation and migratory/metastatic potential. Rac1 is also critical for endothelial cells to grow and form endothelial tubular networks potentiated by angiogenic factors. Importantly, Rac1 controls paracrine signaling of angiogenic factors including VEGF from renal carcinoma cells to surrounding blood vessels. A novel Rac1 inhibitor impaired the growth and migratory potential of both renal carcinoma cells and endothelial cells and reduced VEGF production by RCC cells, thereby limiting paracrine signaling both in vitro and in vivo Lastly, Rac1 was shown to be downstream of VEGF receptor (VEGFR) signaling and required for activation of MAPK signaling. In combination with VEGFR2 inhibitors, Rac inhibition provides enhanced suppression of angiogenesis. Therefore, targeting Rac in ccRCC has the potential to block the growth of tumor cells, endothelial cell recruitment, and paracrine signaling from tumor cells to other cells in the tumor microenvironment.

Paget's disease of the nipple in a Her2-positive breast cancer xenograft model.

PURPOSE: Paget's disease (PD) of the breast is an uncommon disease of the nipple usually accompanied by an underlying carcinoma, often HER2 + , and accounting for 0.5-5% of all breast cancer. To date, histogenesis of PD of the breast remains controversial, as two theories-transformation and epidermotropic-have been proposed to explain this disease. Currently, animal models recapitulating PD of the nipple have not been described. METHODS: HER2-enriched DT13 breast cancer cells were injected into the mammary fat pad of NOD scid gamma null (NSG) female mice. Immunohistochemical staining and pathological studies were performed on tumor samples, and diagnosis of PD of the nipple was confirmed by expression of proteins characteristic of Paget cells (epidermal growth factor 2 (HER2), androgen receptor (AR), cytokeratin 7 (CK7), cytokeratin 8/18 (CK8/18), and mucin 1 (MUC1)). In addition, DT13 cells grown in 2D culture and in soft agar assays were sensitive to in vitro treatment with pharmacological inhibitors targeting Her2, adenylyl cyclase, mTOR, and PI3K signaling pathways. RESULTS: Mice developed tumors and nipple lesions that were detected exclusively on the tumor-bearing mammary fat pad. Tumor cells were positive for proteins characteristic of Paget cells. In vitro, DT13 cells were sensitive to inhibition of Her2, adenylyl cyclase, mTOR, and PI3K signaling pathways. CONCLUSIONS: Our results suggest that injection of HER2 + DT13 cells into the mammary fat pad of NSG mice recapitulates critical aspects of the pathophysiology of PD of the nipple, supporting the epidermotropic theory as the more likely to explain the histogenesis of this disease.

RAC1b Overexpression Confers Resistance to Chemotherapy Treatment in Colorectal Cancer.

Resistance to chemotherapy represents a major limitation in the treatment of colorectal cancer. Novel strategies to circumvent resistance are critical to prolonging patient survival. Rac1b, a constitutively activated isoform of the small GTPase Rac1, is upregulated with disease progression and promotes cell proliferation and inhibits apoptosis by activation of NF-κB signaling. Here, we show that Rac1b overexpression correlates with cancer stage and confirmed Rac1b expression is associated with increased growth through enhancing NF-κB activity. Rac1b knockdown reduced cellular proliferation and reduced NF-κB activity. Surprisingly, Rac1b expression and NF-κB activity were upregulated in cells treated with chemotherapeutics, suggesting that Rac1b facilitates chemo-resistance through activation of NF-κB signaling. Knockdown of Rac1b or Rac inhibition increases the sensitivity of the cells to oxaliplatin. When used in combination, inhibition of Rac prevents the increase in NF-κB activity associated with chemotherapy treatment and increases the sensitivity of the cells to oxaliplatin. Although Rac inhibition or oxaliplatin treatment alone reduces the growth of colorectal cancer in vivo, combination therapy results in improved outcomes compared with single agents alone. We provide the first evidence that Rac1b expression confers resistance to chemotherapy in colorectal cancer. Additionally, we show that the use of a Rac inhibitor prevents chemoresistance by blocking activation of chemotherapy induced NF-κB signaling, providing a novel strategy to overcome resistance to chemotherapy in colorectal cancer.

The effects of a randomized trial of brief forms of stress management on RAGE-associated S100A8/A9 in patients with breast cancer undergoing primary treatment.

BACKGROUND: Women with breast cancer (BCa) experience heightened distress, which is related to greater inflammation and poorer outcomes. The s100 protein family facilitates the inflammatory response by regulating myeloid cell function through the binding of Toll-like receptor 4 and the receptor for advanced glycation end products (RAGE). The heterodimer s100A8/A9 RAGE ligand is associated with hastened tumor development and metastasis. Previously, a 10-week stress-management intervention using cognitive behavioral therapy (CBT) and relaxation training (RT) was associated with less leukocyte inflammatory gene expression in patients with BCa; however, its impact on s100A8/A9 was not examined. Because a 10-week intervention may be impractical during primary treatment for BCa, the authors developed briefer forms of CBT and RT and demonstrated their efficacy in reducing distress over 12 months of primary treatment. Here, the effects of these briefer interventions were tested effects on s100A8/A9 levels over the initial 12 months of BCa treatment. METHODS: Postsurgical patients with BCa (stage 0-IIIB) were randomized to a 5-week, group-based condition: CBT, RT, or health education control (HE). At baseline and at 12 months, women provided sera from which s100A8/A9 levels were determined using any enzyme-linked immunosorbent assay. RESULTS: Participants (mean age ± standard deviation, 54.81 ± 9.63 years) who were assigned to either CBT (n = 41) or RT (n = 38) had significant s100A8/A9 decreases over 12 months compared with those who were assigned to HE (n = 44; F[1,114]  = 4.500; P = .036) controlling for age, stage, time since surgery, and receipt of chemotherapy or radiation. Greater increases in stress-management skills from preintervention to postintervention predicted greater reductions in s100A8/A9 levels over 12 months (ß = -0.379; t[101]  = -4.056; P < .001). CONCLUSIONS: Brief, postsurgical, group-based stress management reduces RAGE-associated s100A8/A9 ligand levels during primary treatment for BCa.

Liquid biopsy: expanding the frontier of circulating biomarker discovery and validation in breast cancer.

Liquid biopsies represent an attractive, minimally-invasive alternative to surgical sampling or complex imaging of breast cancer and breast cancer metastasis. Here we present a summary of the major biomarker components often evaluated in liquid biopsy samples from patients with breast cancer, including circulating tumor cells, circulating cell-free tumor DNA, and cancer-associated plasma proteins. We discuss recent advancements in methods of detection and use of these biomarkers in breast cancer. Finally, we highlight some of our own recent contributions to breast cancer liquid biopsy, including the identification and characterization of circulating Cancer Associated Fibroblasts.

Reduction of Cisplatin-Induced Ototoxicity without Compromising Its Antitumor Activity.

Cisplatin is a major chemotherapeutic that continues to have a significant impact in the treatment of more than 50% of all cancers. Since its Food and Drug Administration approval in 1978 for the treatment of advanced ovarian and bladder cancer, this chemotherapeutic has made significant strides and its application has been extended to a large variety of other cancers. However, the vast majority of patients who receive cisplatin therapy often suffer from nephrotoxicity, neurotoxicity, nausea, and ototoxicity. Numerous methods currently exist for overcoming nephrotoxicity- and nausea-related side effects, but there is no clear prevention to fight ototoxicity and neurotoxicity. In this work, we examined Platin- A, a prodrug of cisplatin and aspirin, using preclinical mouse- and guinea pig-based models and demonstrated its efficacy with reduced ototoxicity. In addition, in vitro studies documented that when Platin- A is used in combination with a clinically relevant dose of radiation, its efficacy can further be improved by attacking cellular bioenergetic profiles, producing multiple modes of DNA damage, and delaying repair of damaged DNA. These studies demonstrated novel properties of the prodrug, Platin- A, highlighting its superior efficacy with reduced toxicity.