A Phase I/II Trial of Cetuximab in Combination with Interleukin-12 Administered to Patients with Unresectable Primary or Recurrent Head and Neck Squamous Cell Carcinoma

PURPOSE

mAbs including cetuximab can induce antibody-dependent cellular cytotoxicity (ADCC) and cytokine production mediated via innate immune cells with the ability to recognize mAb-coated tumors. Preclinical modeling has shown that costimulation of natural killer (NK) cells via the Fc receptor and the IL12 receptor promotes NK-cell-mediated ADCC and production of cytokines.

PATIENTS AND METHODS

This phase I/II trial evaluated the combination of cetuximab with IL12 for the treatment of EGFR-expressing head and neck cancer. Treatment consisted of cetuximab 500 mg/m² i.v. every 2 weeks with either 0.2 mcg/kg or 0.3 mcg/kg IL12 s.c. on days 2 and 5 of the 2-week cycle, beginning with cycle 2. Correlative studies from blood draws obtained prior to treatment and during therapy included measurement of ADCC, serum cytokine, and chemokine analysis, determination of NK cell FcγRIIIa polymorphisms, and an analysis of myeloid-derived suppressor cell (MDSC) frequency in peripheral blood.

RESULTS

The combination of cetuximab and IL12 was well tolerated. No clinical responses were observed, however, 48% of patients exhibited prolonged progression-free survival (PFS; average of 6.5 months). Compared with patients that did not exhibit clinical benefit, patients with PFS >100 days exhibited increased ADCC as therapy continued compared with baseline, greater production of IFNγ, IP-10, and TNFα at the beginning of cycle 8 compared with baseline values and had a predominance of monocytic MDSCs versus granulocytic MDSCs prior to therapy.

CONCLUSIONS

Further investigation of IL12 as an immunomodulatory agent in combination with cetuximab in head and neck squamous cell carcinoma is warranted.

Generation of monocyte-derived tumor-associated macrophages using tumor-conditioned media provides a novel method to study tumor-associated macrophages in vitro

Background

Tumor-associated macrophages (TAM) are expanded and exhibit tumor-promoting properties within the tumor microenvironment. Current methods to study TAM have not been replicated across cancer types and often do not include exogenous growth factors from the tumor, a key factor in TAM differentiation in vivo.

Methods

In this study, an in vitro method to generate monocyte- derived TAM using tumor- conditioned media (TCM) and a cytokine cocktail containing IL-4, IL-10, and M-CSF was utilized to study the phenotype, morphology, and function of TAM across multiple cancer types. TCM was generated from two breast cancer cell lines and an Epstein-Barr virus-positive lymphoma cell line. The properties of in vitro generated TAM were compared to in vitro generated M1 and M2- like macrophages and TAM isolated from patients with cancer.

Results

TAM generated in this fashion displayed an increase in CD163/CD206 co-expression compared to M2- like macrophages (87 and 36%, respectively). TAM generated in vitro exhibited increased transcript levels of the functional markers IL-6, IL-10, CCL2, c-Myc, iNOS, and arginase compared to in vitro generated M2-like macrophages. Functionally, in vitro generated TAM inhibited the proliferation of T cells (47% decrease from M1-like macrophages) and the production of IFN-γ by natural killer cells was inhibited (44%) when co-cultured with TAM. Furthermore, in vitro generated TAM secreted soluble factors that promote the growth and survival of tumor cells.

Conclusions

Limited access to patient TAM highlights the need for methods to generate TAM in vitro. Our data confirm that monocyte-derived TAM can be generated reliably using TCM plus the cytokine cocktail of IL-4, IL-10, and M-CSF. Given the ability of TAM to inhibit immune cell function, continued study of methods to deplete or deactivate TAM in the setting of cancer are warranted.

Electronic supplementary material

The online version of this article (10.1186/s40425-019-0622-0) contains supplementary material, which is available to authorized users.

Cutaneous Melanoma, Version 2.2019, NCCN Clinical Practice Guidelines in Oncology

The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Cutaneous melanoma have been significantly revised over the past few years in response to emerging data on immune checkpoint inhibitor therapies and BRAF-targeted therapy. This article summarizes the data and rationale supporting extensive changes to the recommendations for systemic therapy as adjuvant treatment of resected disease and as treatment of unresectable or distant metastatic disease.

Soy isoflavones and their metabolites modulate cytokine-induced natural killer cell function

Soybeans are a rich source of isoflavones that have been linked with anti-inflammatory processes and various health benefits. However, specific mechanisms whereby soy bioactives impact immune cell subsets are unclear. Isoflavones, such as genistein and daidzein, are metabolized by microbes to bioactive metabolites as O-desmethylangolensin (O-DMA) and equol, whose presence has been linked to health benefits. We examined how soy isoflavones and metabolites impact natural killer (NK) cell signaling and function. We observe no impact of isoflavones on viability of healthy donor peripheral blood mononuclear cells (PBMCs) or NK cells, even at high (25 µM) concentrations. However, pre-treatment of PBMCs with physiologically-relevant concentrations of genistein (p = 0.0023) and equol (p = 0.006) decreases interleukin (IL)-12/IL-18-induced interferon-gamma (IFN-γ) production versus controls. Detailed cellular analyses indicate genistein and equol decrease IL-12/IL-18-induced IFN-γ production by human NK cell subsets, but do not consistently alter cytotoxicity. At the level of signal transduction, genistein decreases IL-12/IL-18-induced total phosphorylated tyrosine, and phosphorylation MAPK pathway components. Further, genistein limits IL-12/IL-18-mediated upregulation of IL-18Rα expression on NK cells (p = 0.0109). Finally, in vivo studies revealed that C57BL/6 mice fed a soy-enriched diet produce less plasma IFN-γ following administration of IL-12/IL-18 versus control-fed animals (p < 0.0001). This study provides insight into how dietary soy modulates NK cell functions.

Increased breast cancer risk in women with neurofibromatosis type 1: a meta-analysis and systematic review of the literature

BACKGROUND

Neurofibromatosis type 1 (NF1) is a cancer predisposing syndrome. Studies suggest that women < 50 years old (y.o.) with NF1 have an increased breast cancer (BC) incidence and BC associated mortality. However, this has not been widely recognized secondary to small study populations.

METHODS

A systematic literature review was conducted through database searches for BC and NF1: 3456 articles identified, 166 reviewed, 58 used for descriptive analysis and 4 utilized for meta-analysis. Fisher's exact tests, Kaplan-Meier curves and random-effects meta-analysis models were used for analysis.

RESULTS

Two hundred eighty-six cases of NF1 and female BC were identified with a median age of 46 years at diagnosis; 53% were <  50. Peak age of BC diagnosis was between 34 to 44 years. Women < 50 y.o. presented with more advanced disease vs. those ≥50 (56% vs. 22% stage III-IV, respectively; p = 0.005). Median survival for the entire cohort was 5 years vs. the reported median BC survival of over 20 years in the general population using the SEER database. Median age at BC death was 48.5 years; 64% of deceased patients were <  50. Meta-analysis of a total of 4178 women with NF1 revealed a BC standardized incidence ratio (SIR) of 3.07 (95%CI 2.16-4.38) for women with NF1 vs. the general population. Women < 50 y.o. demonstrated a higher SIR of 5.08 (95%CI 3.77-6.81) compared to 1.92 (95%CI 1.40-2.63) if ≥50 y.o.

CONCLUSIONS

This systematic literature review and meta-analysis suggests that women with NF1 <  50 y.o. have a five-fold increased risk of BC, present with more advanced disease, and may have an increased BC related mortality. Increased awareness and implementation of recent National Comprehensive Cancer Network early BC screening guidelines for this high-risk patient population is essential. Additional evaluation on the influence of NF1 gene mutations identified in patients undergoing hereditary cancer genetic testing on breast cancer risk in individuals without clinical evidence of NF1 is needed.

Synergy from gene expression and network mining (SynGeNet) method predicts synergistic drug combinations for diverse melanoma genomic subtypes

Systems biology perspectives are crucial for understanding the pathophysiology of complex diseases, and therefore hold great promise for the discovery of novel treatment strategies. Drug combinations have been shown to improve durability and reduce resistance to available first-line therapies in a variety of cancers; however, traditional drug discovery approaches are prohibitively cost and labor-intensive to evaluate large-scale matrices of potential drug combinations. Computational methods are needed to efficiently model complex interactions of drug target pathways and identify mechanisms underlying drug combination synergy. In this study, we employ a computational approach, SynGeNet (Synergy from Gene expression and Network mining), which integrates transcriptomics-based connectivity mapping and network centrality analysis to analyze disease networks and predict drug combinations. As an exemplar of a disease in which combination therapies demonstrate efficacy in genomic-specific contexts, we investigate malignant melanoma. We employed SynGeNet to generate drug combination predictions for each of the four major genomic subtypes of melanoma (BRAF, NRAS, NF1, and triple wild type) using publicly available gene expression and mutation data. We validated synergistic drug combinations predicted by our method across all genomic subtypes using results from a high-throughput drug screening study across. Finally, we prospectively validated the drug combination for BRAF-mutant melanoma that was top ranked by our approach, vemurafenib (BRAF inhibitor) + tretinoin (retinoic acid receptor agonist), using both in vitro and in vivo models of BRAF-mutant melanoma and RNA-sequencing analysis of drug-treated melanoma cells to validate the predicted mechanisms. Our approach is applicable to a wide range of disease domains, and, importantly, can model disease-relevant protein subnetworks in precision medicine contexts.

Effect of topical microporous polysaccharide hemospheres on the duration and amount of fluid drainage following mastectomy: a prospective randomized clinical trial

Background

Seroma formation is the most common complication after mastectomy and places patients at risk of associated morbidities. Microporous polysaccharide hemospheres (MPH) consists of hydrophilic, plant based, polysaccharide particles and is currently used as an absorbable hemostatic agent. An animal model evaluating MPH and seroma formation after mastectomy with axillary lymph node dissection showed a significant decrease in seroma volume. Study aim was to evaluate topical MPH on the risk of post-mastectomy seroma formation as measured by total drain output and total drain days.

Methods

Prospective randomized single-blinded clinical trial of patients undergoing mastectomy for the treatment of breast cancer. MPH was applied to the surgical site in the study group and no application in the control group.

Results

Fifty patients were enrolled; eight were excluded due to missing data. Forty-two patients were evaluated, control (n = 21) vs. MPH (n = 21). No difference was identified between the two groups regarding demographics, tumor stage, total drain days, total drain output, number of clinic visits, or complication rates. On a subset analysis, body mass index (BMI) greater than 30 was identified as an independent risk factor for high drain output. Post hoc analyses of MPH controlling for BMI also revealed no statistical difference.

Conclusions

Unlike the data presented in an animal model, no difference was demonstrated in the duration and quantity of serosanguinous drainage related to the use of MPH in patients undergoing mastectomy for the treatment of breast cancer. BMI greater than 30 was identified as an independent risk factor for high drain output and this risk was not affected by MPH use. NCT03647930, retrospectively registered 08/2018.

Unusual recurrence of breast cancer in a BRCA-variant patient after fat grafting

The oncologic safety of fat grafting procedures remains well-characterized in the recent literature; however, we recommend exercising vigilance when evaluating BRCA-positive and other patients at higher oncologic risk after reconstruction and fat grafting, whose cancer recurrence diagnosis may pose significant clinical challenges.

Concurrent phyllodes tumor, eccrine carcinoma, and multinodular goiter 20 years after radiotherapy for Hodgkin lymphoma

This unusual case of concurrent eccrine adenocarcinoma, phyllodes tumor, and multinodular goiter serves to alert the oncologic community to the high prevalence of second cancers after childhood radiotherapy. Increased surveillance and index of suspicion are recommended to successfully diagnose and treat second primary cancers in this vulnerable population.

Pilot randomized controlled trial of a symptom cluster intervention in advanced cancer

OBJECTIVE

This study evaluated a three-session acceptance-based cognitive behavioral -acceptance and commitment therapy (CBT-ACT) intervention targeting a common symptom cluster in advanced cancer-worry-insomnia-depression-fatigue.

METHODS

Twenty-eight patients with advanced cancer were randomly assigned to the CBT-ACT intervention or waitlist. At preintervention, participants completed a psychodiagnostic interview, standardized questionnaires, and a sleep diary. Intervention and waitlist groups were reassessed after 6 weeks, at which point the waitlist group completed the intervention.

RESULTS

Participants receiving the intervention demonstrated improved sleep efficiency (P = 0.0062, d = 1.08), sleep latency (P = 0.028, d = -0.86), insomnia severity (P = 0.0047, d = -1.18), and worry (P = 0.026, d = -0.89) compared with waitlist controls. They also demonstrated a 7-point reduction on depression (P = 0.03, d = -0.88), reduced hyperarousal (P = 0.005, d = -1.51), and a decrease in distress (P = 0.032, d = -0.83). Effects were maintained for the whole sample in sensitivity analyses. Effects on uncertainty intolerance approached significance (P = 0.058). No effect was found on fatigue.

CONCLUSIONS

The CBT-ACT group performed significantly better than the waitlist control group. CBT-ACT yielded strong effects for worry, sleep, depression, emotional distress, total distress, and hyperarousal. Future studies will enhance the fatigue and uncertainty tolerance components of the intervention.

Alterations in patient plasma microRNA expression profiles following resection of metastatic melanoma

BACKGROUND AND OBJECTIVES

MicroRNAs (miRs) are noncoding RNAs that regulate protein translation and melanoma progression. Changes in plasma miR expression following surgical resection of metastatic melanoma are under-investigated. We hypothesize differences in miR expression exist following complete surgical resection of metastatic melanoma.

METHODS

Blood collection pre- and post-surgical resection was performed in six individuals with solitary melanoma metastases. miR expression in extracted RNA was quantified using the NanoString nCounter Digital Analyzer.

RESULTS

Pre- and post-surgical plasma samples contained 216 miRs with expression above baseline. Comparison of postsurgical to preresection samples revealed differential expression of 25 miRs: miR-let-7a, miR-let7g, miR-15a, miR-16, miR-22, miR-30b, miR-126, miR-140, miR-145, miR-148a, miR-150-5p, miR-191, miR-378i, miR-449c, miR-494, miR-513b, miR-548aa, miR-571, miR-587, miR-891b, miR-1260a, miR 1268a, miR-1976, miR-4268, miR-4454 (P < 0.05). Utilizing P < 0.0046 as a cutoff to control for one false positive among the 216 miRs revealed that postsurgical melanoma plasma samples had upregulation of miR-1260a (P = 0.0007) and downregulation of miR-150-5p (P = 0.0026) relative to pre-surgical samples.

CONCLUSIONS

Differential expression of miR-150-5p and miR-1260a is present in plasma following surgical resection of metastatic melanoma in this small sample (n = 6) of melanoma patients. Therefore, further investigation of these plasma miRs as noninvasive biomarkers for melanoma is warranted.

Abstract A20: Analysis of tumor infiltrating lymphocytes and expression of PD1 and PD-L1 in breast tumors prior to and after neoadjuvant chemotherapy

Introduction: The effect of chemotherapy on the presence of tumor-infiltrating lymphocytes (TILs) and expression of PD1 and PD-L1 is unclear. We sought to describe the differences in the percentage (%) of TILs, cytotoxic T lymphocytes (CTL), and expression of PD1/PD-L1 in tumors of patients (pts) with operable breast cancer (BC) treated with neoadjuvant chemotherapy (NAC) who were enrolled in a biomarker study at our institution (IRB protocol# 2010C0036).

Methods: A multicolor immune-histochemical multiplex assay simultaneously detecting PD1, PD-L1, and CD8 expressing cells was performed on formalin-fixed, paraffin-embedded diagnostic pretreatment biopsy or resected tumor specimen following NAC in 18 of 26 pts participating in the study. A cut-off of ≥1% was considered positive for PD1 and PD-L1 expression. We evaluated stromal and intratumoral CTLs by estimating % of stroma and tumor that contained CD8+ cells. In addition, stromal TILs (sTILs) were identified on full-face hematoxylin and eosin stained sections and defined as the % of tumor stroma containing infiltrating lymphocytes. Pathologic complete or near-complete response (pCR) was analyzed based on residual cancer burden (RCB) score and defined as RCB class 0 or I. Analysis of all slides was performed by an expert breast pathologist. Since the number of pts was limited, we only provide descriptive statistics (mean, range). In addition, because most pts had only a biopsy or only residual tumor available for the analysis, we divided pts into 2 separate cohorts based on what tissue was available.

Results: Of 18 pts, biopsy was analyzed in 7 (Bx cohort) and residual tumor was analyzed in 11 pts (RT cohort). The median age of study pts was 48 (range 32-70); 11 (61%), 6 (33%), and 1 (6%) of pts were Caucasian, African American, and Hispanic, respectively. Ten pts (5 in Bx and RT cohorts each) had triple-negative BC (TNBC), 4 had HER2+ BC (1 and 3 in Bx and RT cohorts, respectively), and 4 had hormone receptor-positive, HER2- BC (1 and 3 in Bx and RT cohorts, respectively). Eight pts (44%) had pCR. In the bx cohort, 85% of pts had pCR while 18% of pts in the RT cohort had minimal residual disease (RCB class I). In the Bx cohort, average % of sTILs was 30% (range 2-70%), including 1 pt (14%) with lymphocyte predominant tumor (≥50% of sTILs). The % of sTILs was similar in the 11 residual tumors (mean 22, range 2-60) with 2 pts having lymphocyte predominant tumors. Average % of CTLs was 19 (range 1-50) in the Bx cohort and 14 (range 1-50) in the RT cohort. An average % of intratumoral CTLs was 8 (range 1-30) and 7.5 (range 0-40) while the average % of stromal CTLs was 25 (range 1-60) and 19 (range 1-60) in the Bx and RT cohorts, respectively. Similar % and trends were seen in 10 TNBC pts. PD-L1 expression was seen in 86% and 36% of tumors in the Bx and RT cohorts, respectively, with majority of expression present in the stroma. All cases of intratumoral PD-L1 expression were also positive for stromal PD-L1 expression. This difference was also seen in the TNBC pts (80% vs. 40% of tumors were PD-L1+ in Bx and RT cohorts, respectively). An average PD-L1 intensity was approximately 3% in both cohorts (range 1-20%). Expression of PD1 was very low (1% intensity in 3 pts in Bx cohort and in 1 pt in RT cohort) and it was seen on CD8+ CTLs.

Conclusion: Our study preliminarily shows that percent of sTILs and stromal and intratumoral CTLs does not differ between pretreatment biopsy and residual tumors following NAC. Lower proportion of residual tumors were PD-L1+ compared to pretreatment biopsy specimen. The study limitations include small number of subjects and lack of comparison in the same pts. Future studies are needed to confirm these findings.

Citation Format: Robert Wesolowski, Zaibo Li, Christopher McQuinn, Maryam Lustberg, Bhuvaneswari Ramaswamy, Anne Noonan, Raquel Reinbolt, Sagar Sardesai, Jeffrey B. VanDeusen, Nicole Williams, William E. Carson, III. Analysis of tumor infiltrating lymphocytes and expression of PD1 and PD-L1 in breast tumors prior to and after neoadjuvant chemotherapy [abstract]. In: Proceedings of the AACR Special Conference: Advances in Breast Cancer Research; 2017 Oct 7-10; Hollywood, CA. Philadelphia (PA): AACR; Mol Cancer Res 2018;16(8_Suppl):Abstract nr A20.

Abstract 5607: Tissue factor is a novel oncotarget for immunotherapy of triple-negative breast cancer using a second generation ICON in orthotopic mouse models of human and murine TNBC cell line- and patient-derived xenografts

Triple-negative breast cancer (TNBC) is often associated with BRCA1 and BRCA2 mutation and is a leading cause of breast cancer death. Due to the lack of validated target molecules, there is currently no approved targeted therapy for TNBC. Tissue factor (TF) is a common yet specific surface target receptor for cancer cells, tumor vascular endothelial cells and cancer stem cells in several types of solid cancers. Here we report evidence supporting the idea that TF is a novel surface target for TNBC patients and cancer lines with BRCA1 and BRCA2 mutations. We showed that TF is over-expressed on TNBC cells and tumor neovasculature in greater than 85% of TNBC patients (n=14) when using standard paraffin-embedded tumor tissues and in nearly 60% of TNBC patients (n=157) when employing tissue microarray slides, but was not detected in adjacent normal breast tissue. We also describe the development of a second-generation TF-targeting immunoconjugate with improved efficacy and higher safety threshold compared to the original immunoconjugate. We showed that L-ICON1 is effective in killing TNBC cells via antibody-dependent cell-mediated cytotoxicity in vitro and in treating human and murine TNBC cell line- and patient-derived xenografts in vivo in preclinical orthotopic mouse models. These results suggest that TF is a novel oncotarget in TNBC and targeting TF may constitute a novel targeted immunotherapy for TNBC patients. The findings in this preclinical study warrant further clinical investigation.

Citation Format: Zhiwei Hu, Rulong Shen, Amanda Campbell, Elizabeth McMichael, Lianbo Yu, Bhuvaneswari Ramaswamy, Cheryl A. London, Tian Xu, William E. Carson. Tissue factor is a novel oncotarget for immunotherapy of triple-negative breast cancer using a second generation ICON in orthotopic mouse models of human and murine TNBC cell line- and patient-derived xenografts [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5607.

Targeting Tissue Factor for Immunotherapy of Triple-Negative Breast Cancer Using a Second-Generation ICON

Triple-negative breast cancer (TNBC) is a leading cause of breast cancer death and is often associated with BRCA1 and BRCA2 mutation. Due to the lack of validated target molecules, no targeted therapy for TNBC is approved. Tissue factor (TF) is a common yet specific surface target receptor for cancer cells, tumor vascular endothelial cells, and cancer stem cells in several types of solid cancers, including breast cancer. Here, we report evidence supporting the idea that TF is a surface target in TNBC. We used in vitro cancer lines and in vivo tumor xenografts in mice, all with BRCA1 or BRCA2 mutations, derived from patients' tumors. We showed that TF is overexpressed on TNBC cells and tumor neovasculature in 50% to 85% of TNBC patients (n = 161) and in TNBC cell line-derived xenografts (CDX) and patient-derived xenografts (PDX) from mice, but was not detected in adjacent normal breast tissue. We then describe the development of a second-generation TF-targeting immunoconjugate (called L-ICON1, for lighter or light chain ICON) with improved efficacy and safety profiles compared with the original ICON. We showed that L-ICON1 kills TNBC cells in vitro via antibody-dependent cell-mediated cytotoxicity and can be used to treat human and murine TNBC CDX as well as PDX in vivo in orthotopic mouse models. Thus, TF could be a useful target for the development of immunotherapeutics for TNBC patients, with or without BRCA1 and BRCA2 mutations. Cancer Immunol Res; 6(6); 671-84. ©2018 AACR.

Modeling combination therapy for breast cancer with BET and immune checkpoint inhibitors

CTLA-4 is an immune checkpoint expressed on active anticancer T cells. When it combines with its ligand B7 on dendritic cells, it inhibits the activity of the T cells. The Bromo- and Extra-Terminal (BET) protein family includes proteins that regulate the expression of key oncogenes and antiapoptotic proteins. BET inhibitor (BETi) has been shown to reduce the expression of MYC by suppressing its transcription factors and to down-regulate the hypoxic transcriptome response to VEGF-A. This paper develops a mathematical model of the treatment of cancer by combination therapy of BETi and CTLA-4 inhibitor. The model shows that the two drugs are positively correlated in the sense that the tumor volume decreases as the dose of each of the drugs is increased. The model also considers the effect of the combined therapy on levels of myeloid-derived suppressor cells (MDSCs) and the overexpression of TNF-α, which may predict gastrointestinal side effects of the combination.

Metaplastic breast cancer in a patient with neurofibromatosis type 1 and somatic loss of heterozygosity

Metaplastic breast carcinoma (MBC) is rare and has a poor prognosis. Here we describe genetic analysis of a 41-yr-old female patient with MBC and neurofibromatosis type I (NF1). She initially presented with pT3N1a, grade 3 MBC, but lung metastases were discovered subsequently. To identify the molecular cause of her NF1, we screened for germline mutations disrupting NF1 or SPRED1, revealing a heterozygous germline single-nucleotide variant (SNV) in exon 21 of NF1 at c.2709G>A, Chr 17: 29556342. By report, this variant disrupts pre-mRNA splicing of NF1 transcripts. No pathogenic mutations were identified in SPRED1. A potential association between MBC and NF1 was reported in eight previous cases, but none underwent detailed genomics analysis. To identify additional candidate germline variants potentially predisposing to MBC, we conducted targeted exome sequencing of 279 established cancer-causing genes in a control blood sample, disclosing four rare SNVs. Analysis of her breast tumor showed markedly altered variant allelic fractions (VAFs) for two (50%) of them, revealing somatic loss of heterozygosity (LOH) at germline SNVs. Of these, only the VAF of the pathogenic SNV in NF1 was increased in the tumor. Tumor sequencing demonstrated five somatic mutations altering TP53, BRCA1, and other genes potentially contributing to cancer formation. Because somatic LOH at certain germline SNVs can enhance their impacts, we conclude that increased allelic imbalance of the pathogenic SNV in NF1 likely contributed to tumorigenesis. Our results highlight a need to assess predisposing genetic factors and LOH that can cause rare, aggressive diseases such as MBC in NF1.

Targeting tissue factor as a novel therapeutic oncotarget for eradication of cancer stem cells isolated from tumor cell lines, tumor xenografts and patients of breast, lung and ovarian cancer

Targeting cancer stem cell (CSC) represents a promising therapeutic approach as it can potentially fight cancer at its root. The challenge is to identify a surface therapeutic oncotarget on CSC. Tissue factor (TF) is known as a common yet specific surface target for cancer cells and tumor neovasculature in several solid cancers. However, it is unknown if TF is expressed by CSCs. Here we demonstrate that TF is constitutively expressed on CD133 positive (CD133+) or CD24-CD44+ CSCs isolated from human cancer cell lines, tumor xenografts from mice and breast tumor tissues from patients. TF-targeted agents, i.e., a factor VII (fVII)-conjugated photosensitizer (fVII-PS for targeted photodynamic therapy) and fVII-IgG1Fc (Immunoconjugate or ICON for immunotherapy), can eradicate CSC via the induction of apoptosis and necrosis and via antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity, respectively. In conclusion, these results demonstrate that TF is a novel surface therapeutic oncotarget for CSC, in addition to cancer cell TF and tumor angiogenic vascular endothelial TF. Moreover, this research highlights that TF-targeting therapeutics can effectively eradicate CSCs, without drug resistance, isolated from breast, lung and ovarian cancer with potential to translate into other most commonly diagnosed solid cancer, in which TF is also highly expressed.

The combination of MLN2238 (ixazomib) with interferon-alpha results in enhanced cell death in melanoma

The ubiquitin-proteasome signaling pathway is critical for cell cycle regulation and neoplastic growth. Proteasome inhibition can activate apoptotic pathways. Bortezomib, a selective proteasome inhibitor, has anti-melanoma activity. MLN2238 (ixazomib), an oral proteasome inhibitor, has improved pharmacotherapeutic parameters compared to bortezomib. Interferon-alpha (IFN-α), an immune boosting agent, is FDA-approved for treatment of melanoma. In this study in vitro and in vivo evaluation of the antitumor potential of ixazomib and combination treatments with ixazomib and IFN-α were performed. Apoptosis induced by ixazomib was first observed at 12 hours and was maximal at 48 hours with similar levels of cell death compared to bortezomib. IFN-α alone had little effect on cell viability in vitro. However, the combination of ixazomib with IFN-α significantly enhanced ixazomib's ability to induce apoptotic cell death in BRAF V600E mutant and BRAF wild-type human melanoma tumor cells. The combination of ixazomib and IFN-α also enhanced inhibition of cell proliferation in BRAF V600E mutant melanoma tumor cells; however, this was not seen in BRAF wild-type cells. Ixazomib-induced apoptosis was associated with processing of the pro-apoptotic proteins procaspase-3, -7, -8, and -9, and cleavage of poly-ADP-ribose polymerase (PARP). In an in vivo xenograft model of human melanoma, combination treatment with IFN-α-2b and ixazomib demonstrated a significant reduction in tumor volume when compared to vehicle (p = 0.005) and single therapy ixazomib (p = 0.017) and IFN-α-2b (p = 0.036). These pre-clinical results support further evaluation of combination treatment with ixazomib and IFN-α for the treatment of advanced BRAF V600E mutant melanoma.

Nitric Oxide Production by Myeloid-Derived Suppressor Cells Plays a Role in Impairing Fc Receptor-Mediated Natural Killer Cell Function

Purpose: mAbs are used to treat solid and hematologic malignancies and work in part through Fc receptors (FcRs) on natural killer cells (NK). However, FcR-mediated functions of NK cells from patients with cancer are significantly impaired. Identifying the mechanisms of this dysfunction and impaired response to mAb therapy could lead to combination therapies and enhance mAb therapy.Experimental Design: Cocultures of autologous NK cells and MDSC from patients with cancer were used to study the effect of myeloid-derived suppressor cells (MDSCs) on NK-cell FcR-mediated functions including antibody-dependent cellular cytotoxicity, cytokine production, and signal transduction in vitro Mouse breast cancer models were utilized to study the effect of MDSCs on antibody therapy in vivo and test the efficacy of combination therapies including a mAb and an MDSC-targeting agent.Results: MDSCs from patients with cancer were found to significantly inhibit NK-cell FcR-mediated functions including antibody-dependent cellular cytotoxicity, cytokine production, and signal transduction in a contact-independent manner. In addition, adoptive transfer of MDSCs abolished the efficacy of mAb therapy in a mouse model of pancreatic cancer. Inhibition of iNOS restored NK-cell functions and signal transduction. Finally, nonspecific elimination of MDSCs or inhibition of iNOS in vivo significantly improved the efficacy of mAb therapy in a mouse model of breast cancer.Conclusions: MDSCs antagonize NK-cell FcR-mediated function and signal transduction leading to impaired response to mAb therapy in part through nitric oxide production. Thus, elimination of MDSCs or inhibition of nitric oxide production offers a strategy to improve mAb therapy. Clin Cancer Res; 24(8); 1891-904. ©2018 AACR.

Diffusion mapping of drug targets on disease signaling network elements reveals drug combination strategies

The emergence of drug resistance to traditional chemotherapy and newer targeted therapies in cancer patients is a major clinical challenge. Reactivation of the same or compensatory signaling pathways is a common class of drug resistance mechanisms. Employing drug combinations that inhibit multiple modules of reactivated signaling pathways is a promising strategy to overcome and prevent the onset of drug resistance. However, with thousands of available FDA-approved and investigational compounds, it is infeasible to experimentally screen millions of possible drug combinations with limited resources. Therefore, computational approaches are needed to constrain the search space and prioritize synergistic drug combinations for preclinical studies. In this study, we propose a novel approach for predicting drug combinations through investigating potential effects of drug targets on disease signaling network. We first construct a disease signaling network by integrating gene expression data with disease-associated driver genes. Individual drugs that can partially perturb the disease signaling network are then selected based on a drug-disease network "impact matrix", which is calculated using network diffusion distance from drug targets to signaling network elements. The selected drugs are subsequently clustered into communities (subgroups), which are proposed to share similar mechanisms of action. Finally, drug combinations are ranked according to maximal impact on signaling sub-networks from distinct mechanism-based communities. Our method is advantageous compared to other approaches in that it does not require large amounts drug dose response data, drug-induced "omics" profiles or clinical efficacy data, which are not often readily available. We validate our approach using a BRAF-mutant melanoma signaling network and combinatorial in vitro drug screening data, and report drug combinations with diverse mechanisms of action and opportunities for drug repositioning.

Nitric oxide mediated inhibition of antigen presentation from DCs to CD4+ T cells in cancer and measurement of STAT1 nitration

Myeloid derived suppressor cells (MDSC) produce nitric oxide (NO) and inhibit dendritic cell (DC) immune responses in cancer. DCs present cancer cell antigens to CD4⁺ T cells through Jak-STAT signal transduction. In this study, NO donors (SNAP and DETA-NONOate) inhibited DC antigen presentation. As expected, MDSC isolated from peripheral blood mononuclear cells (PBMC) from cancer patients produced high NO levels. We hypothesized that NO producing MDSC in tumor-bearing hosts would inhibit DC antigen presentation. Antigen presentation from DCs to CD4⁺ T cells (T cell receptor transgenic OT-II) was measured via a [³H]-thymidine incorporation proliferation assay. MDSC from melanoma tumor models decreased the levels of proliferation more than pancreatic cancer derived MDSC. T cell proliferation was restored when MDSC were treated with inhibitors of inducible nitric oxide synthase (L-NAME and NCX-4016). A NO donor inhibited OT II T cell receptor recognition of OT II specific tetramers, thus serving as a direct measure of NO inhibition of antigen presentation. Our group has previously demonstrated that STAT1 nitration also mediates MDSC inhibitory effects on immune cells. Therefore, a novel liquid chromatography-tandem mass spectrometry assay demonstrated that nitration of the STAT1-Tyr701 occurs in PBMC derived from both pancreatic cancer and melanoma patients.

NCCN Guidelines Insights: Melanoma, Version 3.2016

The NCCN Guidelines for Melanoma have been significantly revised over the past few years in response to emerging data on a number of novel agents and treatment regimens. These NCCN Guidelines Insights summarize the data and rationale supporting extensive changes to the recommendations for systemic therapy in patients with metastatic or unresectable melanoma.

Co-stimulation of the fc receptor and interleukin-12 receptor on human natural killer cells leads to increased expression of cd25

Natural killer (NK) cells serve a critical role in the immune response against microbes and developing tumors. We have demonstrated that NK cells produce stimulatory cytokines (e.g., IFN-γ) in response to potent stimulation via immobilized IgG (to engage Fc receptors) and interleukin (IL)-12. CD25 is a component of the high-affinity IL-2R, which promotes NK cell activation in response to low doses of IL-2 such as those released by activated T cells. We hypothesized that stimulation of NK cells via IgG and IL-12 would enhance CD25 expression and promote NK cell anti-tumor activity in response to low-dose IL-2. It was confirmed that this dual stimulation strategy significantly enhanced NK cell CD25 expression compared to unstimulated cells or cells treated with IgG or IL-12 alone. Dual stimulated NK cells also were more responsive to low-dose IL-2. Dual stimulated NK cells subsequently treated with low-dose IL-2 (10 pg/mL) displayed enhanced intracellular signaling as indicated by increased pSTAT5 levels. IFN-γ production and cytotoxicity against K562 cells by NK cells stimulated with low-dose IL-2 was comparable to that of cells treated with high-dose IL-2 (10 ng/mL). Importantly, cells isolated from head and neck cancer patients receiving the mAb cetuximab and IL-12 on a clinical trial displayed increased CD25 expression following combination therapy compared to baseline. Altogether, these findings suggest that FcR and IL-12R co-stimulation induces expression of the high-affinity IL-2R and promotes NK cell anti-tumor activity.

Identification of NRAS isoform 2 overexpression as a mechanism facilitating BRAF inhibitor resistance in malignant melanoma

Activating mutations in BRAF are found in 50% of melanomas and although treatment with BRAF inhibitors (BRAFi) is effective, resistance often develops. We now show that recently discovered NRAS isoform 2 is up-regulated in the setting of BRAF inhibitor resistance in melanoma, in both cell lines and patient tumor tissues. When isoform 2 was overexpressed in BRAF mutant melanoma cell lines, melanoma cell proliferation and in vivo tumor growth were significantly increased in the presence of BRAFi treatment. shRNA-mediated knockdown of isoform 2 in BRAFi resistant cells restored sensitivity to BRAFi compared with controls. Signaling analysis indicated decreased mitogen-activated protein kinase (MAPK) pathway signaling and increased phosphoinositol-3-kinase (PI3K) pathway signaling in isoform 2 overexpressing cells compared with isoform 1 overexpressing cells. Immunoprecipitation of isoform 2 validated a binding affinity of this isoform to both PI3K and BRAF/RAF1. The addition of an AKT inhibitor to BRAFi treatment resulted in a partial restoration of BRAFi sensitivity in cells expressing high levels of isoform 2. NRAS isoform 2 may contribute to resistance to BRAFi by facilitating PI3K pathway activation.