Proteogenomic Analysis of Human Uterine Cervical Cancer (UCC) Reveals Treatment-Resistant Subtypes of UCC

PURPOSE/OBJECTIVE(S)

Locally advanced uterine cervical cancer (UCC) is treated by radiotherapy with concurrent chemotherapy, but heterogenous treatment responses are frequently observed. To better optimize therapeutic options based on molecular signatures, we performed proteogenomic analysis of UCC.

MATERIALS/METHODS

UCC tissue and blood samples were collected from patients who underwent primary radiotherapy ± chemotherapy at the National Cancer Center (NCC) in Korea from July 2004 to March 2020. Most samples were obtained via biopsy. Genomic DNA for WES was isolated from frozen biopsy tumor tissues and peripheral blood buffy-coat of patients. Both global proteome and phosphoproteome were analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Whole exome sequencing, RNA sequencing, global proteomics and phosphoproteomics were performed using 253, 337, and 147 cervical cancer samples, respectively. Patient-derived xenograft were established using intratongue implantation using 2 primary cell lines from sub3 and sub5, and flow cytometric analysis was performed.

RESULTS

Fourteen significantly mutated genes (SMG) were found in our study cohort which include 5 newly identified SMGs. Mutation-phosphorylation analysis revealed association with apoptosis and actin cytoskeleton pathway. Proteogenomic analysis defined 6 molecular subtypes of UCC. Of those, 3 subtypes (i.e., Sub3, Sub5 and Sub6) were associated with treatment-resistant phenotypes. The cell-type deconvolution analysis suggested activated stroma with activation of cancer-associated fibroblast in Sub 3, while Sub5 showed low levels of activated stroma and high levels of myeloid immune cells. FACS analysis of UCC mouse models established from these 2 radio-resistant primary cell lines showed high component of PDGFRA+CAF infiltration in Sub 3, and high level of PVR+CD45+ immune cells mainly composed of polymorphonuclear myeloid-derived suppressor cells (PMN-MDSC) in Sub5. For Sub6, genes and/or protein signatures represented mucin-related processes (e.g., mucin glycosylation/sugar metabolism), which are linked to metastasis-associated Tn antigen production.

CONCLUSION

The proteogenomic analysis thus suggests potential targets for radiotherapy-resistant subtypes of UCC; secretory factors from activated stroma and cancer-associated fibroblast (Sub3); RHOA signaling, PVR, and PMN-MDSCs (Sub5), and keratin/chondroitin sulfate proteoglycan and Tn antigen production (Sub6). Our study shows the importance of proteogenomic analysis in unveiling the subtype specific molecular pathways of UCC that are beyond reach by genomic data alone. The validity of our molecular pathway and cellular signatures linking these pathways should be further validated through detailed functional experiments and in larger UCC cohorts.

Fast transmethylation of serum lipids using microwave irradiation

Microwave irradiation as the energy source for one-step direct transesterification of fatty acids in human serum lipids was examined in a solvent system of methanol: hexane: acetyl chloride based on a Lepage & Roy assay. Innovative and explosion proof single-mode or multimode microwave accelerated reaction system was employed. Recoveries were calculated as the percentage of fatty acid concentrations measured by microwave assay to those by the reference method of the Lepage & Roy assay that utilized conductive heating at 100 °C for 60 min. Under conditions of 100 °C for 1 min in Single-mode (S4-100 × 1), or 125 °C for 5 min in Multimode (M5-125 × 5), the recoveries were 100-103 % for the total fatty acids and 96-106 % for each categorized fatty acid, including saturates, monounsaturates, n-6 PUFA, and n-3 PUFA. For individual PUFA, the mean recoveries were 102-105 % for 18:2n-6 and 18:3n-3; 99, 109, and 95 % for 20:4n-6, 20:5n-3, and 22:6n-3, respectively. Thus, fatty acid concentrations determined by microwave fatty acid assay were accurate to those results by the reference method, when the microwave conditions were optimal. In summary, the microwave irradiation could replace conductive heating in one-step direct transesterification, and reduce the duration from 60 min to 5 min or less. This methodology may be applied in both the absolute and relative quantification of serum total fatty acids.

Suicide deaths of active-duty US military and omega-3 fatty-acid status: a case-control comparison

BACKGROUND

The recent escalation of US military suicide deaths to record numbers has been a sentinel for impaired force efficacy and has accelerated the search for reversible risk factors.

OBJECTIVE

To determine whether deficiencies of neuroactive, highly unsaturated omega-3 essential fatty acids (n-3 HUFAs), in particular docosahexaenoic acid (DHA), are associated with increased risk of suicide death among a large random sample of active-duty US military.

METHOD

In this retrospective case-control study, serum fatty acids were quantified as a percentage of total fatty acids among US military suicide deaths (n = 800) and controls (n = 800) matched for age, date of collection of sera, sex, rank, and year of incident. Participants were active-duty US military personnel (2002-2008). For cases, age at death ranged from 17-59 years (mean = 27.3 years, SD = 7.3 years). Outcome measures included death by suicide, postdeployment health assessment questionnaire (Department of Defense Form 2796), and ICD-9 mental health diagnosis data.

RESULTS

Risk of suicide death was 14% higher per SD of lower DHA percentage (OR = 1.14; 95% CI, 1.02-1.27; P < .03) in adjusted logistic regressions. Among men, risk of suicide death was 62% greater with low serum DHA status (adjusted OR = 1.62; 95% CI, 1.12-2.34; P < .01, comparing DHA below 1.75% [n = 1,389] to DHA of 1.75% and above [n = 141]). Risk of suicide death was 52% greater in those who reported having seen wounded, dead, or killed coalition personnel (OR = 1.52; 95% CI, 1.11-2.09; P < .01).

CONCLUSION

This US military population had a very low and narrow range of n-3 HUFA status. Although these data suggest that low serum DHA may be a risk factor for suicide, well-designed intervention trials are needed to evaluate causality.