Whole exome sequencing (WES) reveals novel therapeutic targets in cervical cancer

AbstractObjectiveThe aim of this study was to validate a whole exome sequencing approach to longitudinally characterize the tumor mutational profile of cervical cancer patients undergoing chemoradiation (CRT).Experimental DesignCervical cancer tumor specimens from twenty-seven patients undergoing chemoradiation were collected before and throughout CRT and whole exome sequencing (WES) was performed to characterize individual mutations and alterations in unique genes. WES data were analyzed from cervical cancer patients in The Cancer Genome Atlas (TCGA) as a comparison group.ResultsOver 93% of mutated genes detected at baseline were present in TCGA. Tumor purity from collected swabs correlated with MRI tumor volumes during the course of treatment (R2=0.969). CDK4/CDK6/cyclin D1-related gene mutations involved in the ERK1/2, p16INK4, and p53 pathway and G1/S checkpoint most commonly persisted at the end of CRT.ConclusionThis non-invasive swab technique to serially sample tumor during CRT will allow new discoveries of dynamic tumor mutational profile changes during chemoradiation for mucosal tumors. Mutations that survived or increased during the initial weeks of radiation treatment are potential drivers of radiation resistance including the CDL4/CDK6/cyclin D1-related pathway.Statement of Translational RelevanceThere are no established biomarkers to predict chemoradiation (CRT) response for cervical cancer patients. Serial biopsies cannot be performed due to risks of bleeding and fistula. We used a novel non-invasive swab-based biopsy technique to obtain serial samples from a cohort of twenty-seven patients through the course of treatment, and validated this approach to obtain whole exome sequencing data. We analyzed dynamic tumor mutation profiles during CRT. Results from this study show that mutations in CDK4/CDK6/cyclin D1-related genes increased at the end of CRT, suggesting this pathway as a potential driver of radiation resistance.

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Whole-exome sequencing of cervical carcinomas identifies activating ERBB2 and PIK3CA mutations as targets for combination therapy

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1911385116 ◽

2019 ◽

Vol 116 (45) ◽

pp. 22730-22736 ◽

Cited By ~ 6

Author(s):

Luca Zammataro ◽

Salvatore Lopez ◽

Stefania Bellone ◽

Francesca Pettinella ◽

Elena Bonazzoli ◽

...

Keyword(s):

Cervical Cancer ◽

Exome Sequencing ◽

Whole Exome Sequencing ◽

Cell Lines ◽

Copy Number ◽

Mtor Pathway ◽

In Vivo Models ◽

Whole Exome

The prognosis of advanced/recurrent cervical cancer patients remains poor. We analyzed 54 fresh-frozen and 15 primary cervical cancer cell lines, along with matched-normal DNA, by whole-exome sequencing (WES), most of which harboring Human-Papillomavirus-type-16/18. We found recurrent somatic missense mutations in 22 genes (including PIK3CA, ERBB2, and GNAS) and a widespread APOBEC cytidine deaminase mutagenesis pattern (TCW motif) in both adenocarcinoma (ACC) and squamous cell carcinomas (SCCs). Somatic copy number variants (CNVs) identified 12 copy number gains and 40 losses, occurring more often than expected by chance, with the most frequent events in pathways similar to those found from analysis of single nucleotide variants (SNVs), including the ERBB2/PI3K/AKT/mTOR, apoptosis, chromatin remodeling, and cell cycle. To validate specific SNVs as targets, we took advantage of primary cervical tumor cell lines and xenografts to preclinically evaluate the activity of pan-HER (afatinib and neratinib) and PIK3CA (copanlisib) inhibitors, alone and in combination, against tumors harboring alterations in the ERBB2/PI3K/AKT/mTOR pathway (71%). Tumors harboring ERBB2 (5.8%) domain mutations were significantly more sensitive to single agents afatinib or neratinib when compared to wild-type tumors in preclinical in vitro and in vivo models (P = 0.001). In contrast, pan-HER and PIK3CA inhibitors demonstrated limited in vitro activity and were only transiently effective in controlling in vivo growth of PIK3CA-mutated cervical cancer xenografts. Importantly, combinations of copanlisib and neratinib were highly synergistic, inducing long-lasting regression of tumors harboring alterations in the ERBB2/PI3K/AKT/mTOR pathway. These findings define the genetic landscape of cervical cancer, suggesting that a large subset of cervical tumors might benefit from existing ERBB2/PIK3CA/AKT/mTOR-targeted drugs.

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