High-efficiency lysis of cervical cancer by allogeneic NK cells derived from umbilical cord progenitors is independent of HLA status

John P Veluchamy,Tanja D De Gruijl,Hans J Van Der Vliet,A Marijne Heeren,Jan Spanholtz,Ekaterina S Jordanova,Jaap D H Van Eendenburg,Henk M Verheul,Gemma G Kenter,Daniëlle A M Heideman

doi:10.1007/s00262-016-1919-1

John P Veluchamy, Tanja D De Gruijl + Show 8 more

Open Access

https://doi.org/10.1007/s00262-016-1919-1

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Abstract

Down-regulation of HLA in tumor cells, low numbers and dysfunctionality of NK cells are commonly observed in patients with end-stage cervical cancer. Adoptive transfer of high numbers of cytotoxic NK cells might be a promising treatment approach in this setting. Here, we explored the cytotoxic efficacy on ten cervical cancer cell lines of activated allogeneic NK cells from two sources, i.e., peripheral blood (PBNK) with and without cetuximab (CET), a tumor-specific monoclonal antibody directed against EGFR, or derived from umbilical cord blood (UCB-NK). Whereas CET monotherapy was ineffective against the panel of cervical cancer cell lines, irrespective of their EGFR expression levels and despite their RASwt status, it significantly enhanced the in vitro cytotoxic efficacy of activated PBNK (P = 0.002). Equally superior cytotoxicity over activated PBNK alone was achieved by UCB-NK (P < 0.001). Both PBNK- and UCB-NK-mediated cytotoxic activity was dependent on the NK-activating receptors natural killer group 2, member D receptor (NKG2D) and DNAX accessory molecule-1 (DNAM-1) (P < 0.05) and unrelated to expression levels of the inhibitory receptors HLA-E and/or HLA-G. Most strikingly, whereas the PBNK’s cytotoxic activity was inversely correlated with HLA-ABC levels (P = 0.036), PBNK + CET and UCB-NK cytotoxicity were entirely independent of HLA-ABC expression. In conclusion, this study provides a rationale to initiate a clinical trial for cervical cancer with adoptively transferred allogeneic NK cells, employing either UCB-NK or PBNK + CET for EGFR-expressing tumors. Adoptive transfer of UCB-NK might serve as a generally applicable treatment for cervical cancer, enabled by HLA-, histology- and HPV-independent killing mechanisms.

Highlights

Persistent infection of the cervical epithelium by high-risk HPV can lead to cervical intraepithelial neoplasia which may progress to invasive cervical cancer, such as squamous cell carcinoma, adenosquamous cell carcinoma or adenocarcinoma [1,2,3].Treatment for cervical cancer includes conventional surgery, chemotherapy and/or radiation
Cervical cancer cell lines were sensitive in varying degrees to peripheral blood NK cells (PBNK)-induced cell lysis (Fig. 1a), independent of their EGFR expression levels (Fig. 1b), with consistently and significantly higher cytotoxicity rates when coated with CET (P = 0.002) (Fig. 1c)
PBNK degranulation levels were low in combination with CET upon exposure to cervical cancer cell lines expressing low levels of EGFR (C33a, HeLa and SiHa: denoted in Fig. 2c by triangles)

Summary

Introduction

Treatment for cervical cancer includes conventional surgery, chemotherapy and/or radiation. Targeted intervention strategies using small molecules, angiogenesis inhibitors and monoclonal antibodies directed against specific tumor antigens and proliferation pathways have had limited success in restricting cervical tumor growth so far [4, 5]. EGFR is variably expressed in 80 % of the tumor tissues [6]. Overexpression of EGFR has been associated with poor prognosis in cervical cancer, making EGFR an obvious candidate for therapeutic targeting [7, 8]. Treatment with cetuximab (CET) (chimeric IgG1, antiEGFR mAb) as monotherapy or CET in combination with chemotherapy was ineffective in patients with cervical cancer, in spite of the apparent absence of activating mutations in the EGFR pathway [9, 10]

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