A case of cetuximab-induced radiation recall skin dermatitis and review of the literature.

Radiation recall presents as an acute inflammatory reaction triggered by systemic therapy, usually chemotherapy, and is typically limited to an area that was previously irradiated. Radiation recall reactions are generally self-limiting and most commonly occur in the skin. Many systemic agents have been described to elicit a radiation recall reaction, but the exact pathogenesis is largely unknown. Here, we describe the first reported case of radiation recall dermatitis following cetuximab. While cetuximab is associated with other skin reactions, oncologists should not exclude radiation recall dermatitis as a potential complication of cetuximab infusion in patients with prior radiation, and special attention should be paid to the pattern of skin changes both in terms of location and chronology.

Correction: Evaluation of deacetylase inhibition in metaplastic breast carcinoma using multiple derivations of preclinical models of a new patient-derived tumor.

[This corrects the article DOI: 10.1371/journal.pone.0226464.].

Family history and pathogenic/likely pathogenic germline variants in prostate cancer patients.

BACKGROUND: Recent literature highlights the importance of germline genetic testing in prostate cancer (PCa) patients. Surprisingly, a literature review indicates that family history (FH) records are incomplete in the major published studies from prostate cancer patients. METHODS: Prospective family history data were gathered from 496 men in a single institution with a personal history of PCa who underwent germline genetic testing using a panel of at least 79 genes. Comprehensive first degree FH were obtained in all PCa of patients and analysis of prevalent FH was assessed at the time of sample collection. RESULTS: Pathogenic/likely pathogenic variants (PV/LPVs) were not associated with age at diagnosis, race, or presence of metastasis. One or more first degree relatives (FDR) with any cancer was not predictive for germline PV/LPVs for men with PCa (p = .96). Separate analysis of patients with one or more FDR with breast, prostate, ovarian, or pancreatic cancer revealed that only FDR with breast or ovarian cancer was predictive for PV/LPVs (p = .028, p = .015 respectively). Patients with a FDR with breast cancer had 1.8 increased risk of PV/LPVs, and patients with a FDR with ovarian cancer had 2.9 increased risk of PV/LPV. CONCLUSION: In men with a personal history of PCa, germline PV/LPVs were associated with a FDR with breast or ovarian cancer. Notably having FDRs with PCa does not predict for PV/LPVs. These data emphasize the contribution of FH in a data set with complete ascertainment of FH.

Therapeutic Potential of Adipose Stem Cells.

Adipose stem cells (ASCs) have gained attention in the fields of stem cells regenerative medicine due to their multifaceted therapeutic capabilities. Promising preclinical evidence of ASCs has supported the substantial interest in the use of these cells as therapy for human disease. ASCs are an adult stem cell resident in adipose tissue with the potential to differentiation along mesenchymal lineages. They also are known to be recruited to sites of inflammation where they exhibit strong immunomodulatory capabilities to promote wound healing and regeneration. ASCs can be isolated from adipose tissue at a relatively high yield compared to their mesenchymal cell counterparts: bone marrow-derived mesenchymal stem cells (BM-MSCs). Like BM-MSCs, ASCs are easily culture expanded and have a reduced immunogenicity or are perhaps immune privileged, making them attractive options for cellular therapy. Additionally, the heterogeneous cellular product obtained after digestion of adipose tissue, called the stromal vascular fraction (SVF), contains ASCs and several populations of stromal and immune cells. Both the SVF and culture expanded ASCs have the potential to be therapeutic in various diseases. This review will focus on the preclinical and clinical evidence of SVF and ASCs, which make them potential candidates for therapy in regenerative medicine and inflammatory disease processes.

Evaluation of deacetylase inhibition in metaplastic breast carcinoma using multiple derivations of preclinical models of a new patient-derived tumor.

Metaplastic breast carcinoma (MBC) is a clinically aggressive and rare subtype of breast cancer, with similar features to basal-like breast cancers. Due to rapid growth rates and characteristic heterogeneity, MBC is often unresponsive to standard chemotherapies; and novel targeted therapeutic discovery is urgently needed. Histone deacetylase inhibitors (DACi) suppress tumor growth and metastasis through regulation of the epithelial-to-mesenchymal transition axis in various cancers, including basal-like breast cancers. We utilized a new MBC patient-derived xenograft (PDX) to examine the effect of DACi therapy on MBC. Cell morphology, cell cycle-associated gene expressions, transwell migration, and metastasis were evaluated in patient-derived cells and tumors after treatment with romidepsin and panobinostat. Derivations of our PDX model, including cells, spheres, organoids, explants, and in vivo implanted tumors were treated. Finally, we tested the effects of combining DACi with approved chemotherapeutics on relative cell biomass. DACi significantly suppressed the total number of lung metastasis in vivo using our PDX model, suggesting a role for DACi in preventing circulating tumor cells from seeding distal tissue sites. These data were supported by our findings that DACi reduced cell migration, populations, and expression of mesenchymal-associated genes. While DACi treatment did affect cell cycle-regulating genes in vitro, tumor growth was not affected compared to controls. Importantly, gene expression results varied depending on the cellular or tumor system used, emphasizing the importance of using multiple derivations of cancer models in preclinical therapeutic discovery research. Furthermore, DACi sensitized and produced a synergistic effect with approved oncology therapeutics on inherently resistant MBC. This study introduced a role for DACi in suppressing the migratory and mesenchymal phenotype of MBC cells through regulation of the epithelial-mesenchymal transition axis and suppression of the CTC population. Preliminary evidence that DACi treatment in combination with MEK1/2 inhibitors exerts a synergistic effect on MBC cells was also demonstrated.

Image-Guided Intensity-Modulated Radiation Therapy for IgG4-Related Ophthalmic Disease.

BACKGROUND: IgG4-related ophthalmic disease is a rare, newly recognized entity with high failure rates on first-line therapy of systemic corticosteroids and no other proven management options. Case Presentation. Here, we present the clinical course of a patient with IgG4 ophthalmic disease who achieved a favorable response from radiotherapy. Our patient initially presented with a history of recurrent painful flares of orbital inflammation, a pathologic diagnosis follicular lymphoid hyperplasia from a right lacrimal gland biopsy, and MRI imaging noting expansion of the lateral rectus muscle of the right eye. Initial treatment with dacryoadenectomy and multiple courses of corticosteroids failed to keep his symptoms at bay. Further evaluation revealed florid IgG4 staining. In this context, he was evaluated for image-guided intensity-modulated radiotherapy (IG-IMRT) to the orbit to 20 Gy in 10 fractions. His ophthalmic symptoms resolved. CONCLUSIONS: This treatment experience suggests radiotherapy may be a favorable option for symptom relief in patients with IgG4-related ophthalmic disease not controlled by corticosteroids.

A novel screening approach comparing kinase activity of small molecule inhibitors with similar molecular structures and distinct biologic effects in triple-negative breast cancer to identify targetable signaling pathways.

Breast cancer affects women globally; the majority of breast cancer-related mortalities are due to metastasis. Acquisition of a mesenchymal phenotype has been implicated in the progression of breast cancer cells to an invasive, metastatic state. Triple-negative breast cancer (TNBC) subtypes have high rates of metastases, recurrence, and have poorer prognoses compared to other breast cancer types, partially due to lack of commonly targeted receptors. Kinases have diverse and pivotal functions in metastasis in TNBC, and discovery of new kinase targets for TNBC is warranted. We previously used a screening approach to identify intermediate-synthesis nonpotent, nonselective small-molecule inhibitors from the Published Kinase Inhibitor Set that reversed the mesenchymal phenotype in TNBC cells. Two of these inhibitors (GSK346294A and GSK448459A) are structurally similar, but have unique kinase activity profiles and exhibited differential biologic effects on TNBC cells, specifically on epithelial-to-mesenchymal transition (EMT). Here, we further interrogate these effects and compare activity of these inhibitors on transwell migration, gene (qRT-PCR) and protein (western blot) expressions, and cancer stem cell-like behavior. We incorporated translational patient-derived xenograft models in these studies, and we focused on the lead inhibitor hit, GSK346294A, to demonstrate the utility of our comparative analysis as a screening modality to identify novel kinase targets and signaling pathways to pursue in TNBC. This study introduces a new method for discovering novel kinase targets that reverse the EMT phenotype; this screening approach can be applied to all cancer types and is not limited to breast cancer.

Obesity-Altered Adipose Stem Cells Promote Radiation Resistance of Estrogen Receptor Positive Breast Cancer through Paracrine Signaling.

Obesity is associated with poorer responses to chemo- and radiation therapy for breast cancer, which leads to higher mortality rates for obese women who develop breast cancer. Adipose stem cells (ASCs) are an integral stromal component of the tumor microenvironment (TME). In this study, the effects of obesity-altered ASCs (obASCs) on estrogen receptor positive breast cancer cell's (ER+BCCs) response to radiotherapy (RT) were evaluated. We determined that BCCs had a decreased apoptotic index and increased surviving fraction following RT when co-cultured with obASCs compared to lnASCs or non-co-cultured cells. Further, obASCs reduced oxidative stress and induced IL-6 expression in co-cultured BCCs after radiation. obASCs produce increased levels of leptin relative to ASCs from normal-weight individuals (lnASCs). obASCs upregulate the expression of IL-6 compared to non-co-cultured BCCs, but BCCs co-cultured with leptin knockdown obASCs did not upregulate IL-6. The impact of shLeptin obASCs on radiation resistance of ER+BCCs demonstrate a decreased radioprotective ability compared to shControl obASCs. Key NOTCH signaling players were enhanced in ER+BBCs following co-culture with shCtrl obASCs but not shLep obASCs. This work demonstrates that obesity-altered ASCs, via enhanced secretion of leptin, promote IL-6 and NOTCH signaling pathways in ER+BCCs leading to radiation resistance.

Acellular Biologic Nipple-Areolar Complex Graft: In Vivo Murine and Nonhuman Primate Host Response Evaluation.

There are more than 3 million breast cancer survivors living in the United States of which a significant number have undergone mastectomy followed by breast and nipple-areolar complex (NAC) reconstruction. Current strategies for NAC reconstruction are dependent on nonliving or nonpermanent techniques, including tattooing, nipple prosthetics, or surgical nipple-like structures. Described herein is a tissue engineering approach demonstrating the feasibility of an allogeneic acellular graft for nipple reconstruction. Nonhuman primate (NHP)-derived NAC tissues were decellularized and their extracellular matrix components analyzed by both proteomic and histological analyses. Decellularized NHP nipple tissue showed the removal of intact cells and greatly diminished profiles for intracellular proteins, as compared with intact NHP nipple tissue. We further evaluated the biocompatibility of decellularized grafts and their potential to support host-mediated neovascularization against commercially available acellular dermal grafts by performing in vivo studies in a murine model. A follow-up NHP pilot study evaluated the host-mediated neovascularization and re-epithelialization of onlay engrafted decellularized NAC grafts. The murine model revealed greater neovascularization in the decellularized NAC than in the commercially available control grafts, with no observed biocompatibility issues. The in vivo NHP model confirmed that the decellularized NAC grafts encourage neovascularization as well as re-epithelialization. These results support the concept that a biologically derived acellular nipple graft is a feasible approach for nipple reconstruction, supporting neovascularization in the absence of adverse systemic responses. Impact statement Currently, women in the United States most often undergo a mastectomy, followed by reconstruction, after being diagnosed with breast cancer. These breast cancer survivors are often left with nipple-areolar complex (NAC) reconstructions that are subsatisfactory, nonliving, and/or nonpermanent. Utilizing an acellular biologically derived whole NAC graft would allow these patients a living and permanent tissue engineering solution to nipple reconstruction.

Adipose Stem Cells and Cancer: Concise Review.

It is well established that the tumor microenvironment plays an important role in cancer development and progression. The tumor microenvironment is composed of neoplastic cells, endothelial cells, pericytes, adipocytes, fibroblasts and other connective tissue cells, extracellular matrix components, multiple stem and progenitor cells, and a diverse array of innate and adaptive immune cells [Nat Rev Cancer 2007;7:139-147]. Understanding the mechanisms behind cell-cell communication in the tumor microenvironment is critical to understanding the drivers of tumorigenesis and metastasis. In this review, we discuss the interactions between adipose stem cells, a critical component of the tumor microenvironment, and various forms of cancer. Stem Cells 2019;37:1261-1266.

Leptin produced by obesity-altered adipose stem cells promotes metastasis but not tumorigenesis of triple-negative breast cancer in orthotopic xenograft and patient-derived xenograft models.

BACKGROUND: Breast cancer is the second leading cause of cancer deaths in the USA. Triple-negative breast cancer (TNBC) is a clinically aggressive subtype of breast cancer with high rates of metastasis, tumor recurrence, and resistance to therapeutics. Obesity, defined by a high body mass index (BMI), is an established risk factor for breast cancer. Women with a high BMI have increased incidence and mortality of breast cancer; however, the mechanisms(s) by which obesity promotes tumor progression are not well understood. METHODS: In this study, obesity-altered adipose stem cells (obASCs) were used to evaluate obesity-mediated effects of TNBC. Both in vitro and in vivo analyses of TNBC cell lines were co-cultured with six pooled donors of obASCs (BMI > 30) or ASCs isolated from lean women (lnASCs) (BMI < 25). RESULTS: We found that obASCs promote a pro-metastatic phenotype by upregulating genes associated with epithelial-to-mesenchymal transition and promoting migration in vitro. We confirmed our findings using a TNBC patient-derived xenograft (PDX) model. PDX tumors grown in the presence of obASCS in SCID/beige mice had increased circulating HLA1+ human cells as well as increased numbers of CD44+CD24- cancer stem cells in the peripheral blood. Exposure of the TNBC PDX to obASCs also increased the formation of metastases. The knockdown of leptin expression in obASCs suppressed the pro-metastatic effects of obASCs. CONCLUSIONS: Leptin signaling is a potential mechanism through which obASCs promote metastasis of TNBC in both in vitro and in vivo analyses.

TrxR1, Gsr, and oxidative stress determine hepatocellular carcinoma malignancy.

Thioredoxin reductase-1 (TrxR1)-, glutathione reductase (Gsr)-, and Nrf2 transcription factor-driven antioxidant systems form an integrated network that combats potentially carcinogenic oxidative damage yet also protects cancer cells from oxidative death. Here we show that although unchallenged wild-type (WT), TrxR1-null, or Gsr-null mouse livers exhibited similarly low DNA damage indices, these were 100-fold higher in unchallenged TrxR1/Gsr-double-null livers. Notwithstanding, spontaneous cancer rates remained surprisingly low in TrxR1/Gsr-null livers. All genotypes, including TrxR1/Gsr-null, were susceptible to N-diethylnitrosamine (DEN)-induced liver cancer, indicating that loss of these antioxidant systems did not prevent cancer cell survival. Interestingly, however, following DEN treatment, TrxR1-null livers developed threefold fewer tumors compared with WT livers. Disruption of TrxR1 in a marked subset of DEN-initiated cancer cells had no effect on their subsequent contributions to tumors, suggesting that TrxR1-disruption does not affect cancer progression under normal care, but does decrease the frequency of DEN-induced cancer initiation. Consistent with this idea, TrxR1-null livers showed altered basal and DEN-exposed metabolomic profiles compared with WT livers. To examine how oxidative stress influenced cancer progression, we compared DEN-induced cancer malignancy under chronically low oxidative stress (TrxR1-null, standard care) vs. elevated oxidative stress (TrxR1/Gsr-null livers, standard care or phenobarbital-exposed TrxR1-null livers). In both cases, elevated oxidative stress was correlated with significantly increased malignancy. Finally, although TrxR1-null and TrxR1/Gsr-null livers showed strong Nrf2 activity in noncancerous hepatocytes, there was no correlation between malignancy and Nrf2 expression within tumors across genotypes. We conclude that TrxR1, Gsr, Nrf2, and oxidative stress are major determinants of liver cancer but in a complex, context-dependent manner.

Drug resistance profiling of a new triple negative breast cancer patient-derived xenograft model.

BACKGROUND: Triple-negative breast cancer (TNBC) represents an aggressive subtype with limited therapeutic options. Experimental preclinical models that recapitulate their tumors of origin can accelerate target identification, thereby potentially improving therapeutic efficacy. Patient-derived xenografts (PDXs), due to their genomic and transcriptomic fidelity to the tumors from which they are derived, are poised to improve the preclinical testing of drug-target combinations in translational models. Despite the previous development of breast and TNBC PDX models, those derived from patients with demonstrated health-disparities are lacking. METHODS: We use an aggressive TNBC PDX model propagated in SCID/Beige mice that was established from an African-American woman, TU-BcX-2 K1, and assess its metastatic potential and drug sensitivities under distinct in vitro conditions. Cellular derivatives of the primary tumor or the PDX were grown in 2D culture conditions or grown in mammospheres 3D culture. Flow cytometry and fluorescence staining was used to quantify cancer stem cell-like populations. qRT-PCR was used to describe the mesenchymal gene signature of the tumor. The sensitivity of TU-BcX-2 K1-derived cells to anti-neoplastic oncology drugs was compared in adherent cells and mammospheres. Drug response was evaluated using a live/dead staining kit and crystal violet staining. RESULTS: TU-BcX-2 K1 has a low propensity for metastasis, reflects a mesenchymal state, and contains a large burden of cancer stem cells. We show that TU-BcX-2 K1 cells have differential responses to cytotoxic and targeted therapies in 2D compared to 3D culture conditions insofar as several drug classes conferred sensitivity in 2D but not in 3D culture, or cells grown as mammospheres. CONCLUSIONS: Here we introduce a new TNBC PDX model and demonstrate the differences in evaluating drug sensitivity in adherent cells compared to mammosphere, or suspension, culture.

Obesity-Altered Adipose Stem Cells Promote ER⁺ Breast Cancer Metastasis through Estrogen Independent Pathways.

Adipose stem cells (ASCs) play an essential role in tumor microenvironments. These cells are altered by obesity (obASCs) and previous studies have shown that obASCs secrete higher levels of leptin. Increased leptin, which upregulates estrogen receptor alpha (ERα) and aromatase, enhances estrogen bioavailability and signaling in estrogen receptor positive (ER⁺) breast cancer (BC) tumor growth and metastasis. In this study, we evaluate the effect of obASCs on ER⁺BC outside of the ERα signaling axis using breast cancer models with constitutively active ERα resulting from clinically relevant mutations (Y537S and D538G). We found that while obASCs promote tumor growth and proliferation, it occurs mostly through abrogated estrogen signaling when BC has constitutive ER activity. However, obASCs have a similar promotion of metastasis irrespective of ER status, demonstrating that obASC promotion of metastasis may not be completely estrogen dependent. We found that obASCs upregulate two genes in both ER wild type (WT) and ER mutant (MUT) BC: SERPINE1 and ABCB1. This study demonstrates that obASCs promote metastasis in ER WT and MUT xenografts and an ER MUT patient derived xenograft (PDX) model. However, obASCs promote tumor growth only in ER WT xenografts.

Panobinostat suppresses the mesenchymal phenotype in a novel claudin-low triple negative patient-derived breast cancer model.

Claudin-low triple negative breast cancer (CL-TNBC) is a clinically aggressive molecular TNBC subtype characterized by a propensity to metastasize, recur and acquire chemoresistance. CL-TNBC has a diverse intra- and extracellular composition and microenvironment, and currently there are no clinically approved targeted therapies. Histone deacetylase inhibitors (HDACi) have been investigated as therapeutic agents targeting invasive TNBC phenotypes. However, further studies are required to evaluate HDAC inhibition in CL-TNBC. Here, we utilize a novel CL- TNBC patient-derived xenograft model to study the various and diverse therapeutic potential targets within CL-TNBC tumors. To evaluate effects of the pan-HDACi panobinostat on metastasis and the mesenchymal phenotype of CL-TNBC, we utilize immunohistochemistry staining and qRT-PCR in in vitro, ex vivo and in vivo studies. Further, we evaluate pan-HDAC inhibition on stem-like subpopulations using 3D mammosphere culture techniques and quantification. Finally, we show that pan- HDACi suppresses collagen expression in CL-TNBC. In this study, we provide evidence that pan-HDAC inhibition has effects on various components of the CL-TNBC subtype, and we demonstrate the potential of our novel CL-TNBC PDX model in therapeutic discovery research.

A novel patient-derived xenograft model for claudin-low triple-negative breast cancer.

BACKGROUND: Triple-negative breast cancer (TNBC) subtypes are clinically aggressive and cannot be treated with targeted therapeutics commonly used in other breast cancer subtypes. The claudin-low (CL) molecular subtype of TNBC has high rates of metastases, chemoresistance and recurrence. There exists an urgent need to identify novel therapeutic targets in TNBC; however, existing models utilized in target discovery research are limited. Patient-derived xenograft (PDX) models have emerged as superior models for target discovery experiments because they recapitulate features of patient tumors that are limited by cell-line derived xenograft methods. METHODS: We utilize immunohistochemistry, qRT-PCR and Western Blot to visualize tumor architecture, cellular composition, genomic and protein expressions of a new CL-TNBC PDX model (TU-BcX-2O0). We utilize tissue decellularization techniques to examine extracellular matrix composition of TU-BcX-2O0. RESULTS: Our laboratory successfully established a TNBC PDX tumor, TU-BCX-2O0, which represents a CL-TNBC subtype and maintains this phenotype throughout subsequent passaging. We dissected TU-BCx-2O0 to examine aspects of this complex tumor that can be targeted by developing therapeutics, including the whole and intact breast tumor, specific cell populations within the tumor, and the extracellular matrix. CONCLUSIONS: Here, we characterize a claudin-low TNBC patient-derived xenograft model that can be utilized for therapeutic research studies.

Melanoma complicating treatment with natalizumab for multiple sclerosis: A report from the Southern Network on Adverse Reactions (SONAR).

A 43-year-old female with multiple sclerosis developed urethral melanoma. The only potential risk factor was treatment with natalizumab, a humanized monoclonal antibody against α4 integrins. To investigate the risk-exposure relationship, we reviewed this case, all other published cases, and cases of natalizumab-associated melanoma reported to regulatory agencies. Data sources included the Food and Drug Administration's (FDA) Adverse Event Reporting System (FAERS) (2004-2014), a FDA Advisory Committee Meeting Report, and peer-reviewed publications. In the United States, the manufacturer maintains an FDA-mandated Tysabri Safety Surveillance Program (part of the Tysabri Outcomes Unified Commitment to Health (TOUCH)) of natalizumab-treated patients. We statistically compared reporting completeness for natalizumab-associated melanoma cases in FAERs for which information was obtained entirely from the TOUCH program versus cases where FAERS information was supplemented by TOUCH program information. FAERS included 137 natalizumab-associated melanoma reports in patients with multiple sclerosis. Median age at melanoma diagnosis was 45 years (range: 21-74 years). Changes in preexisting nevi occurred in 16%, history of cutaneous nevi occurred in 22%, diagnosis within 2 years of beginning natalizumab occurred in 34%, and 74% had primary surgical treatment. Among seven natalizumab-treated MS patients who developed biopsy-confirmed melanoma on treatment and reported in the literature, median age at diagnosis was 41 years (range: 38-48 years); and the melanoma diagnosis occurred following a median of 12 natalizumab doses (range: 1-77 doses). A history of mole or nevi was noted in four patients and a history of prior melanoma was noted in one patient. Completeness scores for reports were significantly lower for FAERS cases reported from the TOUCH program versus FAERS cases supplemented by TOUCH information (median score of 2 vs. 4 items out of 8-possible items, P < 0.0007). Clinicians should monitor existing nevi and maintain suspicion for melanoma developing in natalizumab-treated patients. The TOUCH Safety Surveillance Program, currently focused on progressive multifocal leukoencephalopathy, should be expanded to include information on other serious complications including malignancies, particularly if they are immunologic in nature.