Effectiveness and Toxicity of Five Fraction Prone Accelerated Partial Breast Irradiation

PURPOSE/OBJECTIVE(S)

Accelerated partial breast irradiation (APBI) after breast conserving therapy (BCT) is increasingly used to treat women with early stage breast cancer. Our institution was an early adopter of 5-fraction ABPI and delivers APBI primarily to patients in the prone position. This study reports long term oncologic and cosmetic outcome in a large cohort of women treated with 5-fraction external beam APBI.

MATERIALS/METHODS

We included patients receiving APBI 600 cGy × 5 fx delivered every other day or every day between 2010 and 2022. Late toxicities and clinician and patient rated cosmesis were evaluated for patients with > 6 month follow up. Univariate and multivariate logistic regression models were used to identify clinical and dosimetric factors associated with development of acute and late toxicities, clinician and patient rated cosmesis. All statistical tests were two-sided, and the null hypothesis was rejected for p<0.05. Kaplan Meier methodology was used to calculate overall survival (OS), disease-free survival (DFS) and locoregional recurrence-free survival (LR-RFS).

RESULTS

Four hundred and forty-two patients received APBI either daily (56%) or every other day (44%). Most of the patients (92%) were treated in the prone position. Average mean heart dose was 23 cGy for left-sided and 11 cGy for right-sided breast cancers. Ipsilateral lung V30% ≤ 30%. At a median follow up of 48 months (range: 5.96 - 155 months), 12 (2.7%) patients developed a local recurrence, 14 (3.2%) patients developed a contralateral breast primary, 10 patients (2.3%) developed a distant metastasis and one patient (0.2%) developed a local recurrence followed by a distant metastasis 1 month later. Out of 258 patients with > 6 month follow up, rates of late grade 1-2 telangiectasia, fibrosis, edema, atrophy and hyperpigmentation were 4%, 18%, 1%, 19% and 7% respectively. There was only one late grade 3 event in a patient who developed significant breast atrophy. The rate of good-excellent physician and patient rated cosmesis was 95% and 89% respectively (N = 256 at median follow up of 80 months). On multivariate logistic regression, patients who did not receive any adjuvant endocrine or chemotherapy were at increased risk of developing a local recurrence. Patients with PR negative disease were at increased risk of distant metastasis. Patient who experienced any grade of acute dermatitis during treatment were at increased risk of any high grade (grade ≥ 2) late adverse event and worse physician rated cosmesis. Daily or every other day treatment did not correlate with worse toxicity or clinical outcomes. Plastic surgery involvement, LVI, EIC, lobular histology, and ER negativity did not correlate with an increased risk of recurrence. Five-year LR-RFS, DFS and OS were 98%, 92.5% and 98.6% respectively.

CONCLUSION

Five- fraction APBI delivered primarily in the prone position either daily or every other day was effective with low rates of local recurrence, minimal toxicity and excellent cosmetic scores at long term follow up.

A Phase II Trial Evaluating Rapid Mid-Treatment Nodal Shrinkage to Select for Adaptive Deescalation in p16+ Oropharyngeal Cancer Patients Undergoing Definitive Chemoradiation

PURPOSE/OBJECTIVE(S)

The purpose of this study is to determine if rapid mid-treatment nodal shrinkage (RMNS) can identify patients with p16+ oropharyngeal cancer (OPC) who can be safely deescalated with reduced dose chemoradiation therapy (CRT). The primary endpoint was 2-year progression free survival (PFS).

MATERIALS/METHODS

Inclusion criteria were as follows: T1-3, N1, M0 (AJCC 8th edition) p16+ OPC with <10 pack-year smoking history. All patients were initially planned for standard dose CRT (70 Gy) and weekly cisplatin. Patients were evaluated with a CT scan at week 4 for RMNS, defined as >40% nodal volumetric reduction from baseline. If RMNS was achieved, they proceeded to deescalated CRT (60 Gy). If not, they received standard CRT. Biomarker correlates were collected at baseline and week 4 of CRT including plasma TTMV (tumor tissue modified viral) HPV DNA and MRI diffusion weighted imaging (DWI). Univariate logistic regression analyses (UVA) were performed to evaluate predictors of RMNS. Odds ratios with 95% CI are reported, using a p<0.05 for statistical significance with a two-sided test. Wilcoxon rank sum tests were used to evaluate differences between the two groups using p < 0.05, 2-sided) for statistical significance. All statistical procedures were performed using R () with no adjustments for multiple testing.

RESULTS

Thirty-six patients were enrolled: median age: 60 years; 81% male; primary site: 36% base of tongue, 53% tonsil, 11% both; T-stage: 39% T1, 50% T2, 11% T3; N-stage: 100% N1; any smoking history: 58% yes, 42% no; 67% (n = 24) had RMNS and received deescalated CRT while the remaining proceeded to standard CRT. At a median follow-up of 32.4 months, 2-year PFS between the standard and deescalated groups were 91.7% vs 90.9%, respectively (p = 0.97). All patients with recurrence underwent successful salvage treatment with 2-year OS 100% for all patients. On UVA, rapid TTMV HPV DNA clearance (baseline to week 4) (OR 12.0 [1.65-250], p = 0.034), lower MRI diffusivity (ADC) at baseline (OR 0.79 [0.61-0.97], p = 0.042) and week 4 (OR 0.76 [0.60-0.91], p = 0.009), and higher MRI diffusional kurtosis at baseline (OR 1.09 [1.01-1.21], p = 0.051) and week 4 (OR 1.24 [1.09-1.52], p = 0.009) were significantly associated with RMNS. When comparing the deescalated and standard cohorts, the mean baseline and week 4 MRI ADC were significantly lower and week 4 MRI diffusional kurtosis was significantly higher in the deescalated group.

CONCLUSION

In this phase II study, rapid mid-treatment nodal shrinkage appeared to select favorable risk p16+ oropharynx cancer patients for treatment de-escalation. Rapid clearance of TTMV HPV DNA at week 4 as well as MRI DWI biomarkers of low ADC and high diffusional kurtosis values were correlated with RMNS. A larger study is planned to incorporate RMNS and biomarkers for further treatment de-escalation. Additional trial information is available at ClinicalTrials.gov (Identifier: NCT03215719).

Abstract 1388: Non-thermal plasma-activated medium induces ferroptotic cell death by intracellular ferrous iron overload in head and neck cancer

The notoriously high proliferation rate of cancer cells requires them to constantly deal with the balance adjustment between oxidative stress overload and upregulated protective antioxidant pathways. It puts them in a vulnerable state whenever one piece of this puzzle went out of control. Non-thermal plasma (NTP) is partially ionized gas operated at or around body temperature and has emerged as a new potential anti-cancer therapy due to its ability to release and induce ROS, RNS, and other free radicals as well as generate UV- photon and electromagnetic field; but the specific mechanism and its specificity to cancer cell are still controversial. Using transcriptomic analysis, we previously reported the link between NTP-activated media (NTPAM)and apoptosis; but the sequencing data also revealed a strong Ferroptotic response in all the 6Head and Neck cancer cell lines we checked. Ferroptosis is a newly identified oxidative-regulated cell death, characterized by the iron-dependent generation of lipid peroxidation. In this study, we found the prolonged treatment of NTPAM-induced cell death via the non-canonical ferroptosis pathway by directly increasing intracellular toxic ferrous Iron (Fe2+). We found that the excessive overexpression of HMOX1 under prolonged NTPAM-induced oxidative stress was actually responsible for the surge of intracellular Fe2+ due to the increase of heme degradation. Pharmacological inhibition or RNA silencing of HMOX1 was able to rescue 2 HNC cell lines from NTPAM-induced increased Iron concentration as well as ferroptosis cell death, both in vivo and in vitro. These results suggest NTP directly induces ferroptosis via an increase of Fe2+ concentration by triggering the over-responding of the NRF2 - HMOX1 antioxidant system. This finding could be exploited to develop future NTP-based cancer therapy as well as in combination with other Iron sensitive anti-neoplastic agents; and could be a potential method of overcoming conventional cancer treatment resistance.

Citation Format: QuocKhanh Nguyen, Chan Oh, Seung-Nam Jung, Yudan Piao, Mi Ae Lim, Young Il Kim, Yanli Jin, Hae Jong Kim, Bon Seok Koo. Non-thermal plasma-activated medium induces ferroptotic cell death by intracellular ferrous iron overload in head and neck cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1388.

Mitochondrial ribosomal protein L14 promotes cell growth and invasion through modulating ROS in thyroid cancer

Objectives

The mitochondrial ribosomal protein L14 (MRPL14) is encoded by a nuclear gene and participates in mitochondrial protein translation. In this study, we aimed to investigate the role of MRPL14 in thyroid carcinoma.

Methods

We investigated the association of expression of MRPL14 and clinicopathological features using the The Cancer Genome Atlas (TCGA) and Chungnam National University Hospital (CNUH) databases. Functional studies of MRPL14, including proliferation, migration, invasion, mitochondrial oxidative phosphorylation and reactive oxygen species (ROS) production, were performed in papillary thyroid carcinoma (PTC) cell lines (B-CPAP and KTC-1).

Results

Based on TCGA dataset, PTC tissues lost mitochondrial integrity and showed dysregulated expression of overall mitoribosomal proteins (MRPs) compared with normal thyroid tissues. Of 78 MRPs, MRPL14 was highly expressed in thyroid carcinoma tissues. MRPL14 overexpression was significantly associated with advanced tumor stage, extrathyroidal extension, and lymph node metastasis. MRL14 increased cell proliferation of thyroid cancer and promoted cell migration via epithelial-mesenchymal transition-related proteins. Moreover, MRPL14 knockdown reduced the expression of oxidative phosphorylation complex IV (MTCO1) and increased the accumulation of ROS. Co-treatment with a ROS scavenger restored cell proliferation and migration reduced by MRPL14 knockdown, which imply that ROS functions as a key regulator of the oncogenic effects of MRPL14 in thyroid cancer cells.

Conclusion

Our findings indicate that MRPL14 may promote cell growth, migration, and invasion through modulating ROS in thyroid cancer cells.

Claudin-1 mediates progression by regulating EMT through AMPK/TGF-β signaling in head and neck squamous cell carcinoma

Claudin-1 (CLDN1), a major component of tight junction complexes in the epithelium, maintains cellular polarity, and plays a critical role in cell-to-cell communication as well as epithelial cell homeostasis. Although the role of CLDN1 has been widely studied in cancer, its role in the progression and the exact regulatory mechanisms, remain controversial. Using next-generation sequencing, we first analyzed the expression profiles of tumor/non-tumor paired tissue in patients with head and neck squamous cell carcinoma (HNSC) from public and local cohorts and found out that CLDN1 is upregulated in tumors compared to normal tissues. Next, its correlation with lymph node metastasis and poor prognosis was validated in the retrospective cohort, which collectively suggests CLDN1 as an oncogene in HNSC. As expected, the knockdown of CLDN1 inhibited invasive phenotypes by downregulating epithelial-to-mesenchymal transition (EMT) in vitro. To ascertain the regulatory mechanism of CLDN1 in HNSC analysis of GO term enrichment, KEGG pathways, and curated gene sets were used. As a result, CLDN1 was negatively associated with AMP-activated protein kinase (AMPK) and positively associated with transforming growth factor-β (TGF-β) signaling. In vitro mechanistic assay showed that CLDN1 inhibited AMPK phosphorylation by regulating AMPK upstream phosphatases, which led to inhibition of Smad2 activity. Intriguingly, the invasive phenotype of cancer cells increased by CLDN1 overexpression was rescued by AMPK activation, indicating a role of the CLDN1/AMPK/TGF-β/EMT cascade in HNSC. Consistently in vivo, CLDN1 suppression significantly inhibited the tumor growth, with elevated AMPK expression, suggesting the novel observation of oncogenic CLDN1-AMPK signaling in HNSC.

SHMT2 Induces Stemness and Progression of Head and Neck Cancer

Various enzymes in the one-carbon metabolic pathway are closely related to the development of tumors, and they can all be potential targets for cancer therapy. Serine hydroxymethyltransferase2 (SHMT2), a key metabolic enzyme, is very important for the proliferation and growth of cancer cells. However, the function and mechanism of SHMT2 in head and neck cancer (HNC) are not clear. An analysis of The Cancer Genome Atlas (TCGA) data showed that the expression of SHMT2 was higher in tumor tissue than in normal tissue, and its expression was significantly associated with male sex, aggressive histological grade, lymph node metastasis, distant metastasis, advanced TNM stage, and lymphovascular invasion in HNC. SHMT2 knockdown in FADU and SNU1041 cell lines significantly inhibited cell proliferation, colony formation, migration, and invasion. Additionally, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses using TCGA data revealed that SHMT2 was closely related to cancer stem cell regulation and maintenance. Furthermore, we found that silencing SHMT2 inhibited the expression of stemness markers and tumor spheroid formation compared with a control group. On the contrary, stemness markers were significantly increased after SHMT2 overexpression in HEP-2 cells. Interestingly, we found that knocking down SHMT2 reduced the expression of genes related to the Notch and Wnt pathways. Finally, silencing SHMT2 significantly reduced tumor growth and decreased stemness markers in a xenograft model. Taken together, our study suggests that targeting SHMT2 may play an important role in inhibiting HNC progression.

Development and validation of a simple and practical method for differentiating MS from other neuroinflammatory disorders based on lesion distribution on brain MRI

There is an unmet need to develop practical methods for differentiating multiple sclerosis (MS) from other neuroinflammatory disorders using standard brain MRI. To develop a practical approach for differentiating MS from neuromyelitis optica spectrum disorder (NMOSD) and MOG antibody-associated disorder (MOGAD) with brain MRI, we first identified lesion locations in the brain that are suggestive of MS-associated demyelination ("MS Lesion Checklist") and compared frequencies of brain lesions in the "MS Lesion Checklist" locations in a development sample of patients (n = 82) with clinically definite MS, NMOSD, and MOGAD. Patients with MS were more likely than patients with non-MS to have lesions in 3 locations only: anterior temporal horn (p < 0.0001), periventricular ("Dawson's finger") (p < 0.0001), and cerebellar hemisphere (p = 0.02). These three lesion locations were used as predictor variables in a multivariable regression model for discriminating MS from non-MS. The model had area under the curve (AUC) of 0.853 (95% confidence interval: 0.76-0.945), sensitivity of 87.1%, and specificity of 72.5%. We then used an independent validation sample with equal representation of MS and NMOSD/MOGAD cases (n = 97) to validate our prediction model. In the validation sample, the model was 76.3% accurate in discriminating MS from non-MS. Our simple method for predicting MS versus NMOSD/MOGAD only requires a neuroradiologist or clinician to ascertain the presence of lesions in three locations on conventional MRI sequences. It can therefore be readily applied in the real-world setting for training and clinical practice.

The effect of Curcumin on multi-level immune checkpoint blockade and T cell dysfunction in head and neck cancer

BACKGROUND

Despite recent advances in understanding the complex immunologic dysfunction in the tumor microenvironment (TME), fewer than 20% of patients with head and neck squamous cell carcinoma (HNSCC) respond to immune checkpoint blockade (ICB). Thus, it is important to understand how inhibitory IC receptors maintain the suppressed dysfunctional TME, and to develop more effective combination immunotherapy. This study evaluated the immune-modulating effects of Curcumin, which has well-established anti-cancer and chemopreventive properties, and its long-term safety as a phytochemical drug.

METHODS

We carried out the western blot and small interfering RNA (siRNA) transfection assay to evaluate the effects of Curcumin on IC ligands and IC ligands function in HNSCC. Through T-cell cytotoxicity assay and measurements of cytokine secretion, we assessed the effects of combination of Curcumin with programmed death-ligand 1 (PD-L1) Ab on cancer cell killing. Flow cytometry were used to analyze the effects of Curcumin on the expression of programmed cell death protein 1 (PD-1) and T-cell immunoglobulin and mucin-domain3 (TIM-3) on CD4, CD8 and Treg. Immunofluorescence, immunohistochemistry and western blot were used to detecte the cytokine (IFN-γ, Granzyme B), IC receptors (PD-1 and TIM-3) and its ligands (PD-L1, PD-L2, Galectin-9) in xenograft mouse model and 4-nitroquinoline-1-oxide (4-NQO) oral cancer model.

RESULTS

We found that Curcumin decreased the expression of IC ligands such as PD-L1, PD-L2, and Galectin-9 in HNSCC, leading to regulation of epithelial-to-mesenchymal transition-associated tumor invasion. Curcumin also effectively restored the ability of CD8⁺ cytotoxic T cells to lyse cancer cells. To evaluate the effect of Curcumin on the TME further, the 4-NQO oral cancer model was used. Curcumin increased T-cell proliferation, tumor-infiltrating lymphocytes (TILs), and effector cytokines, and decreased the expression of PD-1, TIM-3, suppressive IC receptors and their ligands (PD-L1, PD-L2, and Galectin-9) in the TME, implying reinvigoration of the exhausted CD8⁺ T cells. In addition, Curcumin inhibited expression of CD4⁺CD25⁺FoxP3⁺ Treg cells as well as PD-1 and TIM-3.

CONCLUSIONS

These results show that Curcumin reinvigorates defective T cells via multiple (PD-1 and TIM-3) and multi-level (IC receptors and its ligands) IC axis suppression, thus providing a rationale to combine Curcumin with conventional targeted therapy or ICB as a multi-faceted approach for treating patients with HNSCC.

Transcriptional Regulation of GDF15 by EGR1 Promotes Head and Neck Cancer Progression through a Positive Feedback Loop

Growth and differentiation factor 15 (GDF15), a divergent member of the transforming growth factor-β (TGF-β) superfamily, has been reported to be overexpressed in different kinds of cancer types. However, the function and mechanism of GDF15 in head and neck cancer (HNC) remains unclear. The Cancer Genome Atlas (TCGA) data show that the expression of GDF15 is significantly associated with tumor AJCC stage, lymph vascular invasion and tumor grade in HNC. In this study, we confirmed that knockdown of GDF15 attenuated: cell proliferation, migration and invasion via regulation of EMT through a canonical pathway; SMAD2/3 and noncanonical pathways; PI3K/AKT and MEK/ERK in HNC cell lines. Furthermore, we found that early growth response 1 (EGR1) was a transcription factor of GDF15. Interestingly, we also demonstrated that GDF15 could regulate the expression of EGR1, which meant a positive feedback loop occurred between these two factors. Moreover, combined inhibition of both GDF15 and EGR1 in a HNC mouse xenograft model showed significantly decreased tumor volume compared to inhibition of EGR1 or GDF15 alone. Our study showed that the GDF15–EGR1 signaling axis may be a good target in HNC patients.

POS0134 INCREASED PREVALENCE OF LUMBAR SPINE MONOSODIUM URATE DEPOSITION AMONG GOUT PATIENTS ON DUAL-ENERGY CT

Background:

Gout affecting the spine is reported as a rare event presenting with neuropathy, spinal compression and acute back pain (1). Cases are often diagnosed by tissue confirmation of monosodium urate (MSU) deposition. The frequency of gout involving the spine asymptomatically or with milder, non-specific symptoms is likely higher than reported.

Objectives:

Using dual-energy CT (DECT), we are determining prevalence/extent of MSU deposition in the lumbosacral spines of patients with gout and tophaceous gout, compared to non-gout controls.

Methods:

We are recruiting 25 controls, 25 non-tophaceous and 25 tophaceous gout patients, 45-80 years old. Exclusion criteria include CPPD disease, RA, spondyloarthropathy or spinal malignancy. All gout subjects meet ACR gout classification criteria with entry serum urate (sU) of >6.8 mg/dL, or sU >6.0 mg/dL on ULT for <6 months. Demographics, gout history, Aberdeen back pain scale, sU, ESR, and CRP are collected. DECT of the lumbosacral spine is used to assess MSU deposition and osteoarthritic changes.

Results:

63 subjects are enrolled and analyzed to date (25 control, 23 non-tophaceous and 15 tophaceous gout). Control, non-tophaceous gout, and tophaceous gout subjects have similar mean age in years (controls 61.8±3.8, non-tophaceous 64.0±6.2, tophaceous 63.5±9.2, p=0.45), but differ in BMI (controls 28.3±6.5 kg/m2, non-tophaceous 32.1±6.7 kg/m2, tophaceous 29.1±4.3 kg/m2, p=0.01) and creatinine (controls 1.0±0.2 mg/dL, non-tophaceous 1.4±0.6 mg/dL, tophaceous 1.7±0.9 mg/dL, p=0.048). Mean sU and ESR are higher in gout subjects (sU-controls 5.3±1 mg/dL, non-tophaceous 8.3±1.4 mg/dL, tophaceous 8.4±2.0 mg/dL, p<0.05; ESR-controls 13.7±13.8 mm/h, non-tophaceous 25.2±18.7 mm/h, tophaceous 22.5±15.1 mm/h, p<0.05). Using default threshold settings for MSU visualization, greater MSU deposition is observed in the spine of gout patients (controls 2.2±1.2 cm3, non-tophaceous 4.5±4.3 cm3, tophaceous 8.5±12.5 cm3, p<0.05; Table 1). Reanalysis of several scans using narrower threshold settings to limit possible artifact confirms increased MSU signal among gout patients. Although many subjects in each group do not have excessive MSU deposition, deposition is more common in both gout groups. No subject demonstrated a frank spinal tophus.

Conclusion:

Based on preliminary results, gout patients have higher inflammatory markers and greater spinal MSU deposition than controls. Preliminary analyes with more stringent DECT threshold settings suggests these differences are not artifact, but analysis is ongoing. These data suggest that MSU deposition in the spine occurs in a subset of gout patients.

References:

[1]Toprover M, Krasnokutsky S, Pillinger MH. Gout in the Spine: Imaging, Diagnosis, and Outcomes. Curr Rheumatol Rep. 2015;17(12):70.

Figure 1.

DECT of the spine. (A) Patient with tophaceous gout (SU 8.9mg/dL, DECT volume 39.76cm3). (B) Control patient (SU 4.5mg/dL, DECT volume 0.70cm3).

Table 1.

Baseline characteristics and mean DECT deposition volumes. Bold font indicates statistical significance.

CharacteristicControlNon-tophaceous GoutTophaceous GoutP-valueNumber of subjects252315Age in years, mean ± SD61.8 ± 3.864.0 ± 6.263.5 ± 9.20.45Male sex, n (%)23 (92.0)23 (100.0)13 (86.7)0.23Race:0.52 -White, n (%)18 (72.0)14 (60.9)7 (46.7) -Black, n (%)6(24.0)6 (26.1)6 (40.0) -Hispanic, n (%)1 (4.0)3 (13.0)2 (13.3)BMI, mean ± SD28.3 ± 6.532.1 ± 6.729.1 ± 4.30.01Chronic kidney disease, n (%)0 (0.0)6 (26.1)3 (20.0)0.03Diabetes mellitus type II, n (%)3 (12.0)5 (21.7)2 (13.3)0.62Hyperlipidemia, n (%)14 (56.0)15 (65.2)7 (46.7)0.52History of myocardial infarction, n (%)1 (4.0)2 (8.7)1 (6.7)0.80Mean sU, mg/dL ± SD5.31 ± 0.988.25 ± 1.48.42 ± 2.0<0.001Mean ESR, mm/hr ± SD (normal 0-10)13.7 ± 13.825.2 ± 18.722.53 ± 15.10.04Mean CRP, mg/L ± SD (normal 0-5)2.7 ± 4.77.6 ± 12.54.1 ± 5.00.13Mean serum creatinine, mg/dL ± SD0.97 ± 0.181.36 ± 0.581.70 ± 0.880.048Mean DECT volume, cm32.2 ± 1.24.5 ± 4.38.5 ± 12.5p<0.05

Acknowledgements:

Supported by an investigator-initiated grant from Horizon Therapeutics

Disclosure of Interests:

Michael Toprover Consultant of: Horizon Pharmaceuticals, Michael Mechlin: None declared, Anastasia Slobodnick: None declared, Virginia C. Pike: None declared, Cheongeun Oh: None declared, Claudine Davis: None declared, Theodore Fields Consultant of: Horizon Pharmaceuticals, Avion Pharmaceuticals, Fabio Becce Consultant of: Horizon Therapeutics, Michael H. Pillinger Consultant of: Horizon Pharmaceuticals, Grant/research support from: Horizon Pharmaceuticals

Growth Differentiation Factor 15 is a Cancer Cell-Induced Mitokine That Primes Thyroid Cancer Cells for Invasiveness

Background: Mitochondrial stress is known to activate the mitochondrial unfolded protein response (UPR^mt). The UPR^mt results in the secretion of mitochondrial cytokines (mitokines), which can promote a hormetic response cell nonautonomously, and has been reported to be protumorigenic. Growth differentiation factor 15 (GDF15) is a well-characterized mitokine, which is reported to have a mitohormetic effect. Thus, we investigated whether GDF15 induction could prime a subpopulation of thyroid cancer cells to provide invasive advantages. Methods: The UPR^mt, including mitokine expression, was assessed in the context of thyroid cancer in vitro and in vivo. GDF15 expression in 266 patients with papillary thyroid carcinoma (PTC) was determined by immunohistochemistry. The serum levels of GDF15 were measured in healthy subjects and PTC patients. In addition, our own and The Cancer Genome Atlas data were analyzed to determine the expression level of GDF15 in thyroid cancers. The role of GDF15 in tumor aggressiveness was investigated by observing the effects of GDF15 knockdown in BCPAP, TPC-1, 8505C, and FRO cells. Results: Pharmacological inhibition of mitochondrial oxidative phosphorylation function in thyroid cancer cells robustly increased GDF15 expression. The expression of GDF15 was associated with activation of the mitochondrial integrated stress response pathway in PTC patients. Circulating GDF15 levels were significantly higher in PTC patients than in the controls, and tumor expression of GDF15 was related to tumor aggressiveness. In vitro and in vivo knockdown of GDF15 in a thyroid cancer model showed decreased viability, migration, and invasion compared with the control cells via regulation of STAT3. Conclusions: In this study, we demonstrated that GDF15 is a mitokine induced in thyroid cancer cells upon mitochondrial stress. GDF15-induced STAT3 activation determined tumor progression in thyroid cancer. The GDF15-STAT3 signaling axis may be a target in aggressiveness of thyroid cancer.

Effect of Urban Particulate Matter on Vocal Fold Fibrosis through the MAPK/NF-κB Signaling Pathway

Particulate matter (PM) is an environmental exposure factor that adversely affects human health. PM is a risk factor for various diseases. However, the mechanism by which PM affects the vocal folds (VF) has not yet been evaluated. Thus, we investigated the cytotoxic effects of PM on human vocal fold fibroblasts (hVFF) and the underlying signaling pathways. hVFF were isolated from human VF. The effect of PM on hVFF, and the underlying mechanism, were analyzed using Western blot, quantitative real-time polymerase chain reaction, and flow cytometry. In addition, a histological evaluation was performed in animal experiments. Cell proliferation decreased after the PM treatment. PM increased the expression of interleukin (IL)-6 and IL-1β. The generation of reactive oxygen species (ROS) in PM-treated hVFF and subsequent activation of the mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) pathways were confirmed. Furthermore, PM increased the expression of fibrosis-related markers and induced the accumulation of collagen in the extracellular matrix. As a result, PM exposure significantly enhances the inflammatory response on VF through the ROS-mediated activation of the MAPK and NF-κB signaling pathways. In addition, PM promotes differentiation into myofibroblasts and induces fibrosis. These results suggest that PM triggers an inflammatory reaction through ROS production and causes VF fibrosis.

Association between the microbiomes of tonsil and saliva samples isolated from pediatric patients subjected to tonsillectomy for the treatment of tonsillar hyperplasia

Oral microbes have the capacity to spread throughout the gastrointestinal system and are strongly associated with multiple diseases. Given that tonsils are located between the oral cavity and the laryngopharynx at the gateway of the alimentary and respiratory tracts, tonsillar tissue may also be affected by microbiota from both the oral cavity (saliva) and the alimentary tract. Here, we analyzed the distribution and association of the microbial communities in the saliva and tonsils of Korean children subjected to tonsillectomy because of tonsil hyperplasia (n = 29). The microbiome profiles of saliva and tonsils were established via 16S rRNA gene sequencing. Based on the alpha diversity indices, the microbial communities of the two groups showed high similarities. According to Spearman’s ranking correlation analysis, the distribution of Treponema, the causative bacterium of periodontitis, in saliva and tonsils was found to have a significant positive correlation. Two representative microbes, Prevotella in saliva and Alloprevotella in tonsils, were negatively correlated, while Treponema 2 showed a strong positive correlation between saliva and tonsils. Taken together, strong similarities in the microbial communities of the tonsils and saliva are evident in terms of diversity and composition. The saliva microbiome is expected to significantly affect the tonsil microbiome. Furthermore, we suggest that our study creates an opportunity for tonsillar microbiome research to facilitate the development of novel microbiome-based therapeutic strategies.

Analysing the microbes on tonsils and in saliva from the mouths of children in South Korea provides comparisons of the microbial populations in these distinct but nearby regions, offering possible guidance for developing new therapies for various oral diseases. Researchers in South Korea led by Yoon Shin Park at Chungbuk National University, Cheongju, and Jae Won Chang at Chungnam National University, Daejeon, examined surgically removed tonsils from 29 patients, together with samples of the patients’ saliva. They identified many specific microbe types, finding broad similarities between the populations of an individual’s tonsils and saliva. They also identified positive and negative correlations between the presence of specific microbes in the two populations. The results could guide future treatment choices, including the use of microbes to treat disease.

Brn3a/Pou4f1 Functions as a Tumor Suppressor by Targeting c-MET/STAT3 Signaling in Thyroid Cancer

BACKGROUND

Brn3a/Pou4f1 is a class IV POU domain-containing transcription factor and has been found to be expressed in a variety of cancers. However, the mechanism and action of Brn3a in thyroid cancer has not been investigated.

PURPOSE

To investigate the role of Brn3a in thyroid cancer progression and its clinical implication.

METHODS

We examined Brn3a expression status in patients with thyroid cancer and analyzed relationships between Brn3a expression and clinicopathological findings using The Cancer Genome Atlas (TCGA) database. For functional in vitro analysis, proliferation, migration, invasion assay, and Western blotting were performed after overexpression or suppression of Brn3a.

RESULTS

The promoter hypermethylation of Brn3a was found in patients with aggressive thyroid cancer and Brn3a was downregulated in tissues of patients with thyroid cancer. In TCGA database, the low-Brn3a-expression group revealed a more aggressive phenotype, including T stage and extrathyroid extension when compared with the high-Brn3a-expression group. Overexpression of Brn3a suppressed cell migration and invasion via regulation of epithelial-mesenchymal transition (EMT)-associated proteins in thyroid cancer cell lines. Brn3a overexpression also downregulated signal transducer and activator of transcription 3 (STAT3) signaling through suppression of tyrosine-protein kinase Met (c-MET). In contrast, knockdown of Brn3a by small interfering ribonucleic acid (siRNA) significantly increased cell migration and invasion through upregulation of c-MET/STAT3. These results imply that Brn3a suppresses tumor metastasis via c-MET/STAT3 inhibition and EMT suppression in thyroid cancer.

CONCLUSIONS

Our findings show that Brn3a is a potential tumor suppressor that leads to reduced cancer cell migration and invasion in thyroid cancer. Elucidation of the Brn3a-regulated cancer pathways may therefore provide novel therapeutic strategies to control thyroid cancer metastasis.

Abstract 795: GDF15, the putative mitokine factor, promotes tumor progression in thyroid cancer via STAT3 regulation

Purpose: As mitochondrial dysfunction is an integral component during the initial stages of tumorigenesis, mechanistic insight on the interaction between these two pathways may lead to novel therapeutic approaches. The aim of this study is to investigate the role of GDF15, the putative mitokine factor in thyroid tumorigenesis.

Methods: Expression levels of GDF15 was investigated using The Cancer Genome Atlas database. The role of GDF15 in tumor aggressiveness was investigated by analyzing the effects of knock-down of GDF15 on proliferation, migration, and invasion of thyroid cancer cells. Serum levels of GDF15 were measured in healthy subjects and patients with papillary thyroid cancer (PTC), and expression of GDF15 by IHC was investigated in PTC samples. To investigate the exact mechanism of GDF15 in thyroid cancer, both IPA analysis and GSEA analysis were performed using TCGA database and RNA seq data from Chungnam national university hospital.

Results: TCGA data revealed the higher expression of GDF15 in tumor samples compared to in paired non-tumor samples. Thyroid cancer cells with knock-down of GDF15 revealed the decrease of proliferation, migration, and invasion compared to control cells via regulation of STAT3. Higher serum levels of GDF15 were found in patients with thyroid cancer than in control participants, and were significantly associated with tumor stage, lymphovascular invasion, and recurrence. In addition, patients with high GDF15 expression by IHC revealed the aggressive phenotype compared to patients with low GDF15 expression.

Conclusions: GDF15 is a new biomarker for predicting tumor progression, and therapies targeting GDF15 may be effective for treating thyroid cancer.

Citation Format: Yea Eun Kang, Jae Won Chang, Lihua Liu, Kyoungmin Lee, Mi Ae Lim, Seung-Nam Jung, Chan Oh, Ho-Ryun Won, Minho Shong, Bon Seok Koo. GDF15, the putative mitokine factor, promotes tumor progression in thyroid cancer via STAT3 regulation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 795.

LAMB3 is associated with disease progression and cisplatin cytotoxic sensitivity in head and neck squamous cell carcinoma

OBJECTIVES

Laminin subunit beta-3 (LAMB3) is a major component of the basement membrane zone. In our study, we investigated the role of LAMB3 in head and neck squamous cell carcinoma (HNSCC) progression and its clinical implication as a prognostic biomarker.

MATERIALS AND METHODS

A retrospective analysis of 100 patients with HNSCC who had undergone curative surgery from 1999 to 2011 was performed. We evaluated LAMB3 expression by immunohistochemistry and its associations with clinicopathological characteristics and survival. For functional in vitro analyses, cell proliferation, migration, and invasion and western blot assays were performed following LAMB3 suppression. In addition, the role of LAMB3 in cisplatin-induced cytotoxicity was clarified by measuring cell proliferation.

RESULTS

LAMB3 expression was up-regulated in HNSCC cell lines and patient tissues. High LAMB3 expression was significantly associated with positive lymph node metastasis (odds ratio: 6.316; P < 0.001) and poor prognosis in patients with HNSCC. LAMB3 suppression reduced cell migration/invasion via down-regulation of epithelial-to-mesenchymal transition-associated proteins (Vimentin and Slug). Moreover, LAMB3 suppression increased cisplatin cytotoxicity in HNSCC cells.

CONCLUSION

Our findings indicate that LAMB3 may be used as a prognostic biomarker in HNSCC and support that LAMB3 silencing could induce the sensitivity of anti-cancer drugs such as cisplatin.

Preoperative bisphosphonate treatment may adversely affect the outcome after shoulder arthroplasty

AIMS

The aim of this study was to investigate the effects of preoperative bisphosphonate treatment on the intra- and postoperative outcomes of arthroplasty of the shoulder. The hypothesis was that previous bisphosphonate treatment would adversely affect both intra- and postoperative outcomes.

PATIENTS AND METHODS

A retrospective cohort study was conducted involving patients undergoing arthroplasty of the shoulder, at a single institution. Two patients with no previous bisphosphonate treatment were matched to each patient who had received this treatment preoperatively by gender, age, race, ethnicity, body mass index (BMI), and type of arthroplasty. Previous bisphosphonate treatment was defined as treatment occurring during the three-year period before the arthroplasty. The primary outcome measure was the incidence of intraoperative complications and those occurring at one and two years postoperatively. A total of 87 patients were included: 29 in the bisphosphonates-exposed (BP⁺) group and 58 in the non-exposed (BP^-) group. In the BP⁺ group, there were 26 female and three male patients, with a mean age of 71.4 years (51 to 87). In the BP^- group, there were 52 female and six male patients, with a mean age of 72.1 years (53 to 88).

RESULTS

Previous treatment with bisphosphonates was positively associated with intraoperative complications (fracture; odds ratio (OR) 39.40, 95% confidence interval (CI) 2.42 to 6305.70) and one-year postoperative complications (OR 7.83, 95% CI 1.11 to 128.82), but did not achieve statistical significance for complications two years postoperatively (OR 3.45, 95% CI 0.65 to 25.28). The power was 63% for complications at one year.

CONCLUSION

Patients who are treated with bisphosphonates during the three-year period before shoulder arthroplasty have a greater risk of intraoperative and one-year postoperative complications compared with those without this previous treatment.

Abstract S1-01: Whole exome and transcriptome sequencing of resistant ER+ metastatic breast cancer

Background: While great strides have been made in the treatment of estrogen receptor-positive (ER+) metastatic breast cancer (MBC), therapeutic resistance invariably occurs. A better understanding of the underlying resistance mechanisms is critical to enable durable control of this disease.

Methods: We performed whole exome sequencing (WES) and transcriptome sequencing (RNA-seq) on metastatic tumor biopsies from 88 patients with ER+ MBC who had developed resistance to one or more ER-directed therapies. For 27 of these patients, we sequenced the treatment-naïve primary tumors for comparison to the resistant specimens. Tumors were analyzed for point mutations, insertions/deletions, copy number alterations, translocations, and gene expression. Detailed clinicopathologic data was collected for each patient and linked to the genomic information.

Results: WES of all metastatic samples demonstrated several recurrently altered genes whose incidence differed significantly from primary, treatment-naïve ER+ breast cancers sequenced in the TCGA study (TCGA). These include ESR1 mutations (n=17, 19.3%; 32.86 fold enrichment, q.value&lt;7.5e-12), CCND1 amplification (n=52, 59.1%; 2.3 fold enrichment, q.value&lt;0.0073), and MAP2K4 biallelic inactivation (n=14, 15.9%; 3.04 fold enrichment, q.value&lt; 0.054).

Comparing to matched primary samples from the same patient, many alterations were found to be acquired in several cases, including for ESR1, ERBB2, PIK3CA, PTEN, RB1, AKT1, and others. Initial analysis of RNA-seq data from metastatic samples (n=59) allowed classification of individual resistance mechanisms into broader resistance modes based on the observed transcriptional state.

Conclusions: We present a genomic landscape of resistant ER+ MBC using WES and RNA-seq. Multiple genes were recurrently altered in these tumors at significantly higher rates than in ER+ primary breast cancer. When compared with matched primary tumors from the same patient, alterations in these and other genes were often found to be acquired after treatment, suggesting a role in resistance to ER-directed therapies and/or metastasis. Potential resistance mechanisms appear to fall into several categories; integrating RNA-seq data may enhance the ability to identify these categories even when genomic alterations are not identified. Multiple clinically relevant genomic and molecular alterations are identified in metastatic biopsies– with implications for choice of next therapy, clinical trial eligibility, and novel drug targets.

Citation Format: Cohen O, Kim D, Oh C, Waks A, Oliver N, Helvie K, Marini L, Rotem A, Lloyd M, Stover D, Adalsteinsson V, Freeman S, Ha G, Cibulskis C, Anderka K, Tamayo P, Johannessen C, Krop I, Garraway L, Winer E, Lin N, Wagle N. Whole exome and transcriptome sequencing of resistant ER+ metastatic breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr S1-01.

Abstract P3-04-08: The role of HER2 mutations in resistance to endocrine therapy in ER+ breast cancer

Resistance to endocrine therapies in estrogen receptor positive (ER+) metastatic breast cancer is widespread, and understanding the mechanisms whereby these tumors acquire resistance is a critical need. Through whole-exome sequencing of metastatic tumor biopsies from patients with endocrine resistant ER+ metastatic breast cancer, we identified 13 different HER2 mutations, including five in the kinase domain, four in the signaling domain, three in the extracellular domain, and one in the transmembrane region of the protein. Two of the kinase domain mutations (L755S and V777L) have been previously described and shown to be activating and resistant to reversible anti-HER2 targeted therapies; the remaining mutations have not been reported. In several of these patients, whole exome sequencing of a pre-treatment primary tumor did not identify the HER2 mutations seen in the corresponding metastatic tumor, suggesting that they were acquired during therapy. To examine the role of HER2 mutations in endocrine resistance, we generated ER+ breast cancer cell lines (MCF7 and T47D) stably expressing the HER2 mutants observed in our clinical data. Several mutants promoted enhanced growth in charcoal dextran-stripped media, which lacks estradiol and mimics treatment with aromatase inhibitor. In addition, several mutants conferred varying degrees of resistance to fulvestrant and tamoxifen. Taken together, these results suggest that HER2 mutations are associated with acquired resistance to endocrine therapies in patients with ER+ breast cancer. The ability of irreversible anti-HER2 agents as well as other agents that target the HER2 pathway to overcome this resistance is being tested for individual HER2 mutations in vitro. The results from these studies may provide a clinical rationale for therapeutic combination strategies in patients with refractory tumors that have acquired endocrine resistance through HER2 mutations.

Citation Format: Nayar U, Cohen O, Oh C, Wagle N. The role of HER2 mutations in resistance to endocrine therapy in ER+ breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-04-08.

Clinical assessment of rosacea severity: oriental score vs. quantitative assessment method with imaging and biomedical tools

BACKGROUND

Rosacea is a common chronic inflammatory disorder affecting facial skin. Currently, no accurate and objective method is available for assessing the severity of rosacea. Most studies use the National Rosacea Society Standard (NRSS) grading method, which lacks objectivity and yields varying results.

METHODS

Eighteen patients with rosacea were included. Clinical severity was assessed on the basis of the NRSS grade, Investigators' Global Assessment, Patients' Global Assessment, and Dermatology Quality of Life Index. A skin color analysis system was used to measure the facial area showing erythema, and biophysical parameters of facial skin (transepidermal water loss and skin surface hydration) were examined. To find statistical significant in classification severity of the rosacea, statistical analysis was performed with all parameters.

RESULTS

A significant correlation (P < 0.05) was found between the NRSS grade, facial area showing erythema, and biophysical parameters. The latter two factors differed significantly among patients with rosacea of different levels of severity (mild, moderate, severe; P < 0.05).

CONCLUSION

Color imaging systems can be useful and reliable for evaluating the severity of rosacea, in addition to biophysical parameter assessment. The combination of these two analytical methods enabled objective and quantitative evaluation of the severity of rosacea.

Abstract OT2-05-03: The metastatic breast cancer project: A national direct-to-patient research initiative to accelerate genomics research

Over the past decade, genomic characterization of tumors has shed enormous light on the molecular underpinnings of cancer. These discoveries have led to the development of novel therapies and preventive measures that have already revolutionized cancer care. Despite this progress, the genomics of metastatic breast cancer (MBC), one of the leading causes of cancer death in the U.S., remains poorly understood.

The challenge in studying tumor samples from patients with MBC has been that the tumors from most patients are not available for research, largely because the vast majority of patients are cared for in community settings where genomics studies are not typically conducted. To address this, we have launched a nationwide study, The Metastatic Breast Cancer Project, which seeks to empower patients to accelerate cancer research through sharing their samples and clinical information. We have developed an outreach program in collaboration with MBC advocacy organizations to connect MBC patients around the country with genomics research performed at the Broad Institute, allowing them to participate regardless of where they live.

Working with MBC patients and advocates, we designed a website (www.mbcproject.org) with an online questionnaire that allows patients with MBC to provide information about themselves and their cancer. Based on their answers, patients are offered an electronic consent form that explains the risks and benefits of the study and asks for permission to obtain a portion of their stored tumor tissue, a saliva sample, and copies of their medical records. For patients who consent, our clinical research team contacts their physicians and obtains copies of their medical records, which are reviewed to confirm eligibility. Enrolled patients are sent a saliva kit and asked to mail back a saliva sample, which is used to extract germline DNA. The clinical research team also contacts the patient's pathology department and requests a portion of the tumor to be sent to the Broad Institute for genomic analysis. Whole exome and transcriptome sequencing is performed on tumor and germline DNA. Sequencing data are linked to de-identified clinical information, and the resulting data are used to identify drivers of tumorigenesis, mechanisms of response and resistance to therapies, and diagnostic, prognostic, and therapeutic biomarkers. The database of clinically annotated genomic information will be shared with the NIH and the cancer research community. Study updates and discoveries are shared at regular intervals with all patients who complete the initial questionnaire.

This direct-to-patient approach should be particularly enabling for the identification of patients with rare phenotypes or clinical behavior. For this reason, the first cohorts being studied are patients with extraordinary responses to therapies and patients who present with de novo MBC. Additional cohorts will be added in the future, including young women with MBC and patients with drug-resistant MBC. This project seeks to establish a patient-researcher partnership to accelerate genomic discoveries and improve outcomes in MBC, and may ultimately serve as a means to build a new clinical and translational research model for all patients with cancer.

Citation Format: Wagle N, Painter CA, Ilzarbe M, Van Allen EM, Frank E, Oh C, Krevalin M, Lloyd M, Anderka K, Kryukov G, Boehm JS, Winer E, Lander ES, Golub TR. The metastatic breast cancer project: A national direct-to-patient research initiative to accelerate genomics research. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr OT2-05-03.