Approximately one in four cervical cancer patients suffers from recurrence following primary treatment [1]. Even patients diagnosed with early-stage cervical cancer experience cancer recurrence within 2–3 years after surgery at a rate of about 9 out of 100 [2]. In the United States, the median overall survival for recurrent and metastatic cervical cancer is approximately 16.5 months from the start of first-line therapy despite compliance with national treatment guidelines [3]. Furthermore, healthcare disparities worsen patient outcomes based on racial, ethnic, and regional factors [4,5]. Disparities in low-middle-income countries result in cervical cancer being among the top killers of female populations [6].

The standard of care for cervical cancer consists of a combination of surgery, chemotherapy and radiation depending on disease severity. Patients presenting with advanced disease have the option of adding bevacizumab targeted at vascular endothelial growth factor or pembrolizumab targeted at programmed death-ligand 1 to their first-line treatment regimens, however, there remains a need to improve patient prognosis [3]. Given the high toxicities and morbidities caused by current therapies, targeting the elevated metabolism inherent in cancer is a current direction in new anti-cancer drug discovery and development strategies [[7], [8], [9], [10]]. This is particularly relevant for cervical cancer because the vast majority of these tumors are caused by infection with high-risk human papillomavirus (HR-HPV). HR-HPV early oncoproteins cause metabolic reprogramming in cancer cells by interacting with cellular pathways to promote aerobic glycolysis [11]. Alterations in glucose, lipid and amino acid metabolism increase cervical cancer cell proliferation and survival in hostile microenvironments as they arise, metastasize and respond to therapeutic treatments [12].

The novel investigational new drug SHetA2, currently in clinical trial for cervical and other cancers (clinicaltrial.gov: NCT04928508), has the potential to improve cervical cancer therapy by targeting HR-HPV disrupted pathways to inhibit and kill cervical cancer cells without causing toxicity [13,14]. We recently reported that the SHetA2 mechanism of inducing cell death is different in cervical cancer cells in comparison to multiple non-HPV associated cancers studied, including ovarian, endometrial, kidney, lung and head and neck [13]. The main differences involve significant contributions of caspase-independent apoptosis and mitophagy to SHetA2 induced cervical cancer cell death. Metabolic effects of SHetA2 in cervical cancer may also be different due to the effects of HR-HPV in this cancer type. In endometrial cancer cells, SHetA2 inhibited both oxidative phosphorylation (OxPhos) and glycolysis, putting cells into a quiescent state [15], however SHetA2 metabolic effects in cervical cancer are unknown.

The molecular mechanisms of SHetA2 involve its binding to three 70 kD heat shock protein proteins (HSP70s) called mortalin, heat shock cognate 70 (hsc70) and glucose regulated protein (Grp78), and disruption of their folding and support of client proteins and protein complexes [[15], [16], [17]]. SHetA2 interference with mortalin is the likely mechanism by which it caused mitochondrial damage and inhibits OxPhos, because mortalin is primarily located in the mitochondria where it serves a vital role in nuclear-encoded protein import and mitochondrial function [18]. Other client proteins released from mortalin by SHetA2 treatment of endometrial cancer cells include the metabolic enzymes [15]. In cervical cancer cell lines, SHetA2 disruption of hsc70/apoptosis inducing factor (AIF) complexes is associated with nuclear accumulation of AIF and DNA damage [13].

In this study, we evaluated the proteomic and metabolic responses of cervical cancer cells to SHetA2, identified a metabolic-targeted strategy to increase SHetA2 sensitivity of these cell lines, and validated the results in vivo.