Nelfinavir is effective against human cervical cancer cells in vivo: a potential treatment modality in resource-limited settings

Small Molecule Inhibitors of Human Papillomavirus: A Review of Research from 1997 to 2021

Human papillomavirus (HPV) infections are the cause of warts, lesions and cancer, with different types of HPV causing different symptoms. HPV infections are the primary cause of cervical cancer. There are over 220 different types of HPV, and only nine of these can currently be vaccinated. There is a need to treat these viral infections without just treating the symptoms of the infection, as is currently the main method. There is a wide range of small molecules that have been used to inhibit various stages of the HPV infectious cycle. This review examined 132 small molecules from 121 studies that specifically target aspects of HPV infections. HPV DNA encodes for six early genes (E1 to E7, skipping E3) and two late genes (L1 and L2). According to the results, these targets for small molecule inhibitors fall into three categories: those targeting E1 and E2, targeting E6 and E7 and, finally, targeting L1 and L2. Inhibitors of E6 and E7 are the most widely studied targets, with the majority of HPV inhibition in this area. While compounds targeting both E1/E2 and E6/E7 have made it to clinical trials, there has been no significant advancement on the topic.

Combination of Autophagy Selective Therapeutics With Doxil: An Assessment of Pathological Toxicity

Background: Combination therapy of targeted drugs in cancer treatment is a field in constant flux, with research balancing side effects with efficacy. Efficacy from combination therapy is improved either through synthetic lethality or through prevention of recurrent clones. Previous research has shown (hydroxy-)chloroquine is insufficient to disrupt autophagy in tumors. Hence, either combinations or novel autophagy agents are desired. In vivo studies of ovarian cancer have revealed that chloroquine can be combined with up to four other autophagy drugs to suppress ovarian cancer growth. While cancer efficacy is now established for the autophagy drug combination, it is unclear what toxicities may require monitoring in human trials. Additive toxicity with chemotherapy is also unknown.

Methods: To address toxicity in more depth than previous weight-monitoring studies, biochemical and histopathology studies were performed. Mouse groups were treated with autophagy drugs for 2 weeks, with or without the chemotherapy Doxil. After the last dose, mice were processed for blood biochemistry, white blood cell markers, and histopathology.

Results: Data from a comprehensive blood biochemistry panel, flow cytometric measurements of blood cell markers, and histopathology are herein reported. While Doxil presented clear bone marrow and immunologic toxicity, autophagy drugs were overall less toxic and more variable in their presentation of potential toxicities. Only minor additive effects of autophagy drugs with Doxil were observed.

Conclusion: Combinations of autophagy drugs may be considered for therapy in human oncology trials, with possible side effects to monitor informed by these murine pre-clinical data.

Phase 1 trial of nelfinavir added to standard cisplatin chemotherapy with concurrent pelvic radiation for locally advanced cervical cancer

BACKGROUND

Nelfinavir (NFV), an HIV-1 protease inhibitor, has been shown to sensitize cancer cells to chemoradiation (CRT). The objectives of this phase 1 trial were to evaluate safety and identify the recommended phase 2 dose of NFV added to concurrent CRT for locally advanced cervical cancer.

METHODS

Two dose levels of NFV were evaluated: 875 mg orally twice daily (dose level 1 [DL1]) and 1250 mg twice daily (DL2). NFV was initiated 7 days before CRT and continued through CRT completion. Toxicity, radiographic responses, and pathologic responses were evaluated. Serial tumor biopsies (baseline, after NFV monotherapy, on NFV + CRT, and posttreatment) were evaluated by immunohistochemistry, NanoString, and reverse-phase-protein-array analyses.

RESULTS

NFV sensitized cervical cancer cells to radiation, increasing apoptosis and tumor suppression in vivo. Patients (n = 13) with International Federation of Gynecology and Obstetrics stage IIA through IVA squamous cell cervical carcinoma were enrolled, including 7 patients at DL1 and 6 patients at DL2. At DL1, expansion to 6 patients was required after a patient developed a dose-limiting toxicity, whereas no dose-limiting toxicities occurred at DL2. Therefore, DL2 was established as the recommended phase 2 dose. All patients at DL2 completed CRT, and 1 of 6 experienced grade 3 or 4 anemia, nausea, and diarrhea. One recurrence was noted at DL2, with disease outside the radiation field. Ten of 11 evaluable patients remained without evidence of disease at a median follow-up of 50 months. NFV significantly decreased phosphorylated Akt levels in tumors. Cell cycle and cancer pathways also were reduced by NFV and CRT.

CONCLUSIONS

NFV with CRT is well tolerated. The response rate is promising compared with historic controls in this patient population and warrants further investigation.

The Anti-Cancer Properties of the HIV Protease Inhibitor Nelfinavir

Simple Summary

To this day, cancer remains a medical challenge despite the development of cutting-edge diagnostic methods and therapeutics. Thus, there is a continual demand for improved therapeutic options for managing cancer patients. However, novel drug development requires decade-long time commitment and financial investments. Repurposing approved and market-available drugs for cancer therapy is a way to reduce cost and the timeframe for developing new therapies. Nelfinavir is an anti-infective agent that has extensively been used to treat acquired immunodeficiency syndrome (AIDS) in adult and pediatric patients. In addition to its anti-infective properties, nelfinavir has demonstrated potent off-target anti-cancer effects, suggesting that it could be a suitable candidate for drug repurposing for cancer. In this review, we systematically compiled the therapeutic benefits of nelfinavir against cancer as a single drug or in combination with chemoradiotherapy, and outlined the possible underlying mechanistic pathways contributing to the anti-cancer effects.

Abstract

Traditional cancer treatments may lose efficacy following the emergence of novel mutations or the development of chemoradiotherapy resistance. Late diagnosis, high-cost of treatment, and the requirement of highly efficient infrastructure to dispense cancer therapies hinder the availability of adequate treatment in low-income and resource-limited settings. Repositioning approved drugs as cancer therapeutics may reduce the cost and timeline for novel drug development and expedite the availability of newer, efficacious options for patients in need. Nelfinavir is a human immunodeficiency virus (HIV) protease inhibitor that has been approved and is extensively used as an anti-infective agent to treat acquired immunodeficiency syndrome (AIDS). Yet nelfinavir has also shown anti-cancer effects in in vitro and in vivo studies. The anti-cancer mechanism of nelfinavir includes modulation of different cellular conditions, such as unfolded protein response, cell cycle, apoptosis, autophagy, the proteasome pathway, oxidative stress, the tumor microenvironment, and multidrug efflux pumps. Multiple clinical trials indicated tolerable and reversible toxicities during nelfinavir treatment in cancer patients, either as a monotherapy or in combination with chemo- or radiotherapy. Since orally available nelfinavir has been a safe drug of choice for both adult and pediatric HIV-infected patients for over two decades, exploiting its anti-cancer off-target effects will enable fast-tracking this newer option into the existing repertoire of cancer chemotherapeutics.

Single-cell analysis of copy-number alterations in serous ovarian cancer reveals substantial heterogeneity in both low- and high-grade tumors

Unusually high aneuploidy is a hallmark of epithelial serous ovarian cancer (SOC). Previous analyses have focused on aneuploidy on average across all tumor cells. With the expansion of single-cell sequencing technologies, however, an analysis of copy number heterogeneity cell-to-cell is now technically feasible. Here, we describe an analysis of single-cell RNA sequencing (scRNA-seq) data to infer arm-level aneuploidy in individual serous ovarian cancer cells. By first clustering high-quality sequenced epithelial versus non-epithelial cells, high-confidence tumor cell populations were identified. InferCNV was used to predict segmented copy-number alterations (CNAs), which were then used to determine arm-level aneuploidy at the single-cell level. Control comparisons of normal cells to normal cells showed zero arm-level aneuploidy, whereas a median of four aneuploid events were detectable in cancer cells. A heterogeneity analysis of high-grade tumor cells compared to low-grade tumor cells showed similar levels of cell-to-cell variation between cancer grades. Metastatic tumors potentially showed selection pressure with reduced cell-to-cell variation compared to cells from primary tumors. Minor cell populations with CNAs similar to metastatic cells were identified within the matched primary tumors. Taken together, these results provide a minimum estimate for single-cell aneuploidy in serous ovarian cancer and demonstrate the utility of single-cell sequencing for CNA analysis.

Cervical cancer risk and impact of Pap-based screening in HIV-positive women on antiretroviral therapy in Johannesburg, South Africa

Data on invasive cervical cancer (ICC) incidence in HIV-positive women and the effect of cervical cancer screening in sub-Saharan Africa are scarce. We estimated i) ICC incidence rates in women (≥18 years) who initiated antiretroviral therapy (ART) at the Themba Lethu Clinic (TLC) in Johannesburg, South Africa, between 2004 and 2011 and ii) the effect of a Pap-based screening program. We included 10,640 women; median age at ART initiation: 35 years [interquartile range (IQR) 30-42], median CD4 count at ART initiation: 113 cells/µL (IQR 46-184). During 27,257 person-years (pys), 138 women were diagnosed with ICC; overall incidence rate: 506/100,000 pys [95% confidence interval (CI) 428-598]. The ICC incidence rate was highest (615/100,000 pys) in women who initiated ART before cervical cancer screening became available in 04/2005 and was lowest (260/100,000 pys) in women who initiated ART from 01/2009 onward when the cervical cancer screening program and access to treatment of cervical lesions was expanded [adjusted hazard ratio (aHR) 0.42, 95% CI 0.20-0.87]. Advanced HIV/AIDS stage (4 versus 1, aHR 1.95, 95% CI 1.17-3.24) and middle age at ART initiation (36-45 versus 18-25 years, aHR 2.51, 95% CI 1.07-5.88) were risk factors for ICC. The ICC incidence rate substantially decreased with the implementation of a Pap-based screening program and improved access to treatment of cervical lesions. However, the risk of developing ICC after ART initiation remained high. To inform and improve ICC prevention and care for HIV-positive women in sub-Saharan Africa, implementation and monitoring of cervical cancer screening programs are essential.