PD-1/PD-L1 blockade in cervical cancer: current studies and perspectives

Modulation of sHLA-G, PD-1, and PD-L1 Expression in Cervical Lesions Following Imiquimod Treatment and Its Association with Treatment Success

(1) Background: Cervical intraepithelial neoplasia (CIN) is a precancerous condition linked to human papillomavirus (HPV) infection, often necessitating surgical interventions carrying the risk of subsequent preterm births. This study explores the potential of imiquimod (IMQ), as a non-invasive alternative treatment. The focus is on understanding IMQ impact on immune checkpoint molecules, particularly PD-1, PD-L1, and sHLA-G, which play pivotal roles in shaping immune responses and cancer progression. (2) Methods: Forty-three patients diagnosed with a high-risk squamous intraepithelial lesion (HSIL, p16-positive) self-applied 5% IMQ encapsulated in sachets containing 250 g of cream into the vaginal cavity three times a week for 16 weeks. The impact of IMQ therapy on cervical lesion regression was assessed through immunohistochemistry (IHC), examining changes in sHLA-G, PD-L1, and PD-1 levels. The antiviral activity of IMQ was evaluated through HPV-E7 immunofluorescence. Ethical considerations were adhered to, and the research methods were based on a previously approved clinical trial (clinicaltrials.gov Identifier: NCT04859361). (3) Results: IMQ treatment demonstrated efficacy, leading to lesion regression. sHLA-G levels in CIN before starting IMQ application were associated with unsuccessful treatment (p = 0.0036). IMQ did not significantly alter the expression of PD-1. We observed a decrease in PD-L1 levels in those who were successfully treated (p = 0.0509) and a reduction in HPV burden. (4) Conclusions: IMQ exhibits promise as a non-invasive treatment for CIN, emphasising its potential to modulate the immune microenvironment. Baseline sHLA-G levels emerge as potential predictors of treatment response. Understanding the nuanced dynamics of immune checkpoints sheds light on IMQ mechanism of action. Further exploration is warranted to decipher the intricate mechanisms underlying IMQ treatment in the context of cervical lesions.

The expression and significance of PD-L1 in condyloma acuminatum

BACKGROUND

It has been reported that programmed death-ligand 1 (PD-L1) is highly expressed in cells during viral infection, which helps the virus escape host immunity. However, the relationship between human papillomavirus (HPV) and PD-L1 in condyloma acuminatum and whether they participate in immunosuppression have not been reported. In this paper, we aimed to explore the expression and significance of PD-L1 in condyloma acuminatum.

METHODS

The expression of PD-L1 in the wart of condyloma acuminatum patients and the foreskin of healthy individuals was evaluated. Lentivirus transfection was used to introduce the HPV11-E7 gene into HaCaT cells to investigate whether HPV infection could affect the expression of PD-L1. The successfully constructed HPV11-E7 HaCaT cells were cocultured with Jurkat cells, and Jurkat cell apoptosis and proliferation as well as the Jurkat cell cycle were evaluated by flow cytometry and cell counting kit-8 (CCK-8) assays.

RESULTS

PD-L1 was highly expressed in keratinocytes of genital warts. Through the construction of a cell model, we found that HPV11-E7 could upregulate the expression of PD-L1 in HaCaT cells. Furthermore, HPV11-E7 HaCaT cells can promote the apoptosis of Jurkat cells, inhibit the proliferation of Jurkat cells and mediate the cell cycle arrest of Jurkat cells through the PD-1/PD-L1 signalling pathway.

CONCLUSIONS

HPV infection may upregulate PD-L1 expression in the keratinocytes of genital warts and participate in the inhibition of local T-cell function.

Identification of a prognostic model based on immune and hypoxia-related gene expressions in cervical cancer

BACKGROUND

Tumour immune microenvironment (TIME) has long been a key direction of tumour research. Understanding the occurrence, metastasis and other processes of cervical cancer (CC) is of great significance in the diagnosis and prognosis of tumours.

METHODS

Here, this study applied the univariate Cox regression model to determine the prognostic association of immune and hypoxia signature genes in CC, and used Least Absolute Shrinkage and Selection Operator (LASSO) Cox method to build immune and hypoxia related risk score model to uncover the immune signature of the TIME of CC. Moreover, we used in vitro experiment to validate the expression level of signature genes. Notably, we assessed the predictive effect of anti-PD1/PDL1 immunotherapy using risk score model.

RESULTS

Through the LASSO Cox regression model, we obtained 12 characteristic genes associated with the prognosis of CC, and also associated with immunity and hypoxia. Interestingly, the high-risk group had the properties of high hypoxia and low immunity, while the low-risk group had the properties of low hypoxia and high immunity. In the low-risk group, patients lived longer and had a significant therapeutic advantage of anti-PD-1 immunotherapy.

CONCLUSIONS

Established risk scores model can help predict response to anti-PD-1 immunotherapy of CC.

Manipulating TGF-β signaling to optimize immunotherapy for cervical cancer

Cervical cancer is a serious threat to women's health globally. Therefore, identifying key molecules associated with cervical cancer progression is essential for drug development, disease monitoring, and precision therapy. Recently, TGF-β (transforming growth factor-beta) has been identified as a promising target for cervical cancer treatment. For advanced cervical cancer, TGF-β participates in tumor development by improving metastasis, stemness, drug resistance, and immune evasion. Accumulating evidence demonstrates that TGF-β blockade effectively improves the therapeutic effects, especially immunotherapy. Currently, agents targeting TGF-β and immune checkpoints such as PD-L1 have been developed and tested in clinical studies. These bispecific antibodies might have the potential as therapeutic agents for cervical cancer treatment in the future.

Advances in the application of immune checkpoint inhibitors in gynecological tumors

BACKGROUND

Immune checkpoints are regulatory molecules that suppress immune effector cells, and are essential for maintaining tolerance, preventing autoimmune reactions, and minimizing tissue damage by controlling the duration and intensity of the immune responses. However, immune checkpoints are frequently upregulated during cancer and dampen the anti-tumor immune responses. Immune checkpoint inhibitors (ICIs) have been effective against multiple tumors, and have improved patients' survival outcomes. Recent clinical trials have also reported promising therapeutic effects of ICIs in some gynecological cancers.

AIM

To review the current research and future directions in the treatment of gynecological malignancies, including ovarian, cervical and endometrial cancers, using ICIs.

CONCLUSION

Currently, cervical and ovarian cancers are the only gynecological tumors that are treated by immunotherapeutic approaches. In addition, ICIs, chimeric antigen receptor (CAR)- and T cell receptor (TCR)-engineered T cells targeting endometrial tumors, especially those originating in the vulva and fallopian tubes, are under development. Nevertheless, the molecular mechanism underlying the effects of ICIs, especially in combination with chemotherapy, radiation therapy, anti-angiogenesis drugs and poly ADP ribose polymerase inhibitors (PARPi), needs to be elucidated. Furthermore, novel predictive biomarkers have to be identified in order to increase the therapeutic efficacy of ICIs while reducing adverse reactions.

Cervical cancer immune infiltration microenvironment identification, construction of immune scores, assisting patient prognosis and immunotherapy

Background

The immune microenvironment is of great significance in cervical cancer. However, there is still a lack of systematic research on the immune infiltration environment of cervical cancer.

Methods

We obtained cervical cancer transcriptome data and clinical information from the Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) databases, evaluated the immune microenvironment of cervical cancer, determined immune subsets, constructed an immune cell infiltration scoring system, screened key immune-related genes, and performed single-cell data analysis and cell function analysis of key genes.

Results

We combined the TCGA and GEO data sets and obtained three different immune cell populations. We obtained two gene clusters, extracted 119 differential genes, and established an immune cell infiltration (ICI) scoring system. Finally, three key genes, IL1B, CST7, and ITGA5, were identified, and single-cell sequencing data were mined to distribute these key genes in different cell types. By up-regulating CST7 and down-regulating IL1B and ITGA5, cervical cancer cells’ proliferation ability and invasion ability were successfully reduced.

Conclusion

We conducted a comprehensive assessment of the state of the tumor immune microenvironment in cervical cancer, constructed the ICI scoring system, and identified the ICI scoring system as a potential indicator of susceptibility to immunotherapy for cervical cancer, identifying key genes suggesting that IL1B, CST7, and ITGA5 play an essential role in cervical cancer.

Retrospective Analysis of the Predictive Value of 18F-FDG PET/CT Metabolic Parameters for PD-L1 Expression in Cervical Cancer

BACKGROUND

Immunotherapy targeting PD-1/PD-L1 has been proven to be effective for cervical cancer treatment. To explore non-invasive examinations for assessing the PD-L1 status in cervical cancer, we performed a retrospective study to investigate the predictive value of ¹⁸F-FDG PET/CT.

METHODS

The correlations between PD-L1 expression, clinicopathological characteristics and ¹⁸F-FDG PET/CT metabolic parameters were evaluated in 74 cervical cancer patients. The clinicopathological characteristics included age, histologic type, tumor differentiation, FIGO stage and tumor size. The metabolic parameters included maximum standard uptake (SUVmax), mean standard uptake (SUVmean), total lesion glycolysis (TLG) and tumor metabolic volume (MTV).

RESULTS

In univariate analysis, SUVmax, SUVmean, TLG, tumor size and tumor differentiation were obviously associated with PD-L1 status. SUVmax (rs = 0.42) and SUVmean (rs = 0.40) were moderately positively correlated with the combined positive score (CPS) for PD-L1 in Spearman correlation analysis. The results of multivariable analysis showed that the higher SUVmax (odds ratio = 2.849) and the lower degree of differentiation (Odds Ratio = 0.168), the greater probability of being PD-L1 positive. The ROC curve analysis demonstrated that when the cut-off values of SUVmax, SUVmean and TLG were 10.45, 6.75 and 143.4, respectively, the highest accuracy for predicting PD-L1 expression was 77.0%, 71.6% and 62.2%, respectively. The comprehensive predictive ability of PD-L1 expression, assessed by combining SUVmax with tumor differentiation, showed that the PD-L1-negative rate was 100% in the low probability group, whereas the PD-L1-positive rate was 84.6% in the high probability group. In addition, we also found that the H-score of HIF-1α was moderately positively correlated with PD-L1 CPS (rs = 0.51).

CONCLUSIONS

The SUVmax and differentiation of the primary lesion were the optimum predictors for PD-L1 expression in cervical cancer. There was a great potential for ¹⁸F-FDG PET/CT in predicting PD-L1 status and selecting cervical cancer candidates for PD1/PD-L1 immune checkpoint therapy.

[Predictive markers of immunotherapy in cervical cancer]

OBJECTIVE

Study of PD-L1 expression in squamous and adenosquamous cell cervical cancer (CC) by immunohistochemical (IHC) method, assessment of the relationship between PD-L1 tumor status and its clinical and morphological characteristics, TILs, MSI/dMMR, and HPV tumor status.

MATERIAL AND METHODS

Surgical material was obtained from 41 patients with CC, on which the expression of PD-L1, proteins of the MMR system and p16 was studied by the IHC method, the TILs index was determined.

RESULTS

Positive PD-L1 status was found in 51.2% of the studied CC samples. In the study sample, the level of PD-L1 expression depended on the severity of lymphoid infiltration of the tumor (p=0.038), it was shown that a positive PD-L1 status of CC can be expected with a TILs value greater than or equal to 50%. The age of the patients, the histological variant of the tumor, the pT and pN stage, the presence of lymphovascular invasion, and the HPV status did not statistically significantly affect the level of PD-L1 expression, however, there was an association between the PD-L1 status and the grade of CC malignancy (p=0.027). The presence of the MSI/dMMR phenomenon was detected in a small percentage of carcinomas (4.9%), the PD-L1 status of these tumors was determined as positive.

CONCLUSION

A positive PD-L1 status is determined in a significant number of cases of CC, regardless of most of the studied clinical and morphological characteristics; there is a statistically significant relationship between PD-L1 expression and the degree of tumor differentiation and TILs. It has been shown that CC with the MSI/dMMR phenomenon is characterized by a positive PD-L1 status. The authors consider it necessary to study the expression of PD-L1 in patients with cervical carcinomas in order to determine the possibility of prescribing personalized therapy with immune checkpoint inhibitors.

Relationship and prognostic significance of IL-33, PD-1/PD-L1, and tertiary lymphoid structures in cervical cancer

IL-33, an epithelial-derived cytokine, functions as an alarmin for the immune system in the tumor microenvironment (TME). However, the expression and role of IL-33 on cervical cancer remain unclear. The aim of this study was to investigate the expression of IL-33 and its relationship with clinicopathologic features, tertiary lymphoid structures (TLS), and programmed cell death 1 (PD-1)/programmed cell death 1 ligand (PD-L1) immune checkpoints by immunohistochemistry in 93 cervical cancer patient specimens. Down-regulation of IL-33 expression was observed in tumor tissues compared with adjacent tissues. More importantly, IL-33 was detected in the cytoplasm of tumor fraction. IL-33 expression in tumor cytoplasm was associated with tumor size and the invasive depth of tumors (p < 0.05). Meanwhile, IL-33 expression in tumor cytoplasm was positively correlated with infiltration of CD3⁺ T cells, CD8⁺ T cells, and PD-L1 expression in tumor tissues (p < 0.05). The number of TLS strongly correlated with the depth of tumor invasion, preoperative chemotherapy, human papillomavirus infection, and high level of PD-1 (p < 0.05). However, there was no significant relationship between IL-33 and TLS. Kaplan-Meier survival curves showed that the formation of TLS was associated with a better prognosis (p = 0.008). In multivariable Cox regression modeling, high expression of PD-L1 in tumor tissues was correlated with poor prognosis (HR = 0.128; 95% CI: 0.026-0.646; p = 0.013), whereas the high expression of IL-33 in tumor tissues was associated with better prognosis (HR = 5.097; 95% CI:1.050-24.755; p = 0.043). These results indicate that IL-33, TLS, and PD-L1 are potentially valuable prognostic predictor for cervical cancer. IL-33 has potential for combination with PD-L1-related antitumor therapy.

PD-1/PD-L1 inhibitors for advanced or metastatic cervical cancer: From bench to bed

Advanced or metastatic cervical cancer has a poor prognosis, and the 5-year overall survival is <5% with conventional radiotherapy and chemotherapy. Immunotherapy, particularly immune checkpoint inhibitors (ICIs), achieved initial success in advanced solid tumors, while their efficacy and safety in advanced or metastatic cervical cancer remains to be explored. Previous studies found high-risk HPV infection and elevated PD-L1 expression in cervical precancerous lesions and squamous cell carcinoma. Meanwhile, elevated PD-L1 expression, high cytotoxic T lymphocyte infiltration, and abnormal cytotoxic T lymphocyte function might benefit inflammation infiltration for ICIs in the tumor microenvironment. Patients with HPV infection, squamous cell carcinoma, advanced stage, large tumor size, poor differentiation, metastatic disease, history of multiple childbirth and abortion, or a previous history of receiving chemotherapy might be associated with positive PD-L1 expression. Although there is no correlation between PD-L1 expression and prognosis using conventional radiotherapy, patients with high PD-L1 expression have a poorer prognosis. Several clinical studies demonstrate preliminary safety and efficacy for PD-1/PD-L1 inhibitors, and the exploration of combination strategies such as immunotherapy combined with chemotherapy, radiotherapy, anti-angiogenesis therapy, or dual ICIs is ongoing. This paper systematically reviews PD-L1 expression patterns and their relationship with prognosis, along with reported and ongoing clinical trials of PD-1/PD-L1 inhibitors in cervical cancer to clarify the prospect of ICIs for cervical cancer from bench to bed.

Monoclonal antibodies in cervical malignancy-related HPV

Despite many efforts to treat HPV infection, cervical cancer survival is still poor for several reasons, including resistance to chemotherapy and relapse. Numerous treatments such as surgery, radiation therapy, immune cell-based therapies, siRNA combined with various drugs, and immunotherapy are being studied and performed to provide the best treatment. Depending on the stage and size of the tumor, methods such as radical hysterectomy, pelvic lymphadenectomy, or chemotherapy can be utilized to treat cervical cancer. While accepted, these treatments lead to interruptions in cellular pathways and immune system homeostasis. In addition to a low survival rate, cervical neoplasm incidence has been rising significantly. However, new strategies have been proposed to increase patient survival while reducing the toxicity of chemotherapy, including targeted therapy and monoclonal antibodies. In this article, we discuss the types and potential therapeutic roles of monoclonal antibodies in cervical cancer.

A comprehensive bioinformatic analysis of cyclin-dependent kinase 2 (CDK2) in glioma

BACKGROUND

Glioma is one of the most prevalent malignant brain tumors and its incidence is rising continuously in recent years. Studies suggested that the regulatory mechanism of CDK2 in glioma might different from most of the other cancer types METHODS: Data were accessed from TCGA, GTEx, CGGA, CancerSEA, and TISCH. The expressions of CDK2 in tumors, normal tissues, and different groups of gliomas were compared. The association between CDK2 and the overall survival of glioma patients was analyzed and validated, and a prognostic model was constructed. CDK2-associated genes were enriched in the GO and the KEGG pathways. The association of CDK2 and tumor immunity and functions were analyzed. The subtypes of glioma cells expressing CDK2 were identified.

RESULTS

CDK2 was overexpressed in glioma compared to normal brain tissues. CDK2 was overexpressed in higher grade glioma compared to lower grade glioma. CDK2 expression was higher in groups related to poor prognostic factors in low-grade glioma but had no difference in high-grade glioma. CDK2 was associated with worse overall survival in overall glioma and within low-grade glioma. A survival prediction nomogram was constructed. The enrichment study revealed that the low expression of CDK2 was associated with genes regulating normal brain functions while the high expression of CDK2 was associated with genes regulating immune cells and cancer. CDK2 was negatively correlated with B cells, T cells CD4+, and T cells CD8+. CDK2 was positively correlated with endothelial cells, macrophage, and NK cells. CDK2 high group had higher expression of the immune checkpoint genes, and the calculation suggested that patients with a lower CDK2 expression were much more likely to respond to immunotherapy.

CONCLUSION

CDK2 was a potential diagnostic and prognostic biomarker and novel tumor immune environment sign for glioma patients.

LOXL2 small molecule inhibitor restrains malignant transformation of cervical cancer cells by repressing LOXL2-induced epithelial-mesenchymal transition (EMT)

Lysyl oxidase-like 2 (LOXL2) is a member of the lysine oxidase (LOX) family. Although its overexpression is known to play pivotal roles in carcinogenesis, its involvement in cervical cancer remains undefined. Here, we comprehensively explored the expression level and functional mechanism of LOXL2 in cervical cancer using bioinformatics and experimental methods. Bioinformatics analysis revealed that LOXL2 was significantly upregulated in cervical cancer compared to normal tissues. Enrichment analysis showed that most positively or negatively correlated genes of LOXL2 were correlated with extracellular matrix (ECM) formation and epithelial-mesenchymal transition (EMT). Further experiments confirmed that overexpression of LOXL2 greatly enhanced the malignant transformation abilities (e.g., proliferation, invasion, and migration) of cervical cancer cells via mediation of EMT. Furthermore, the small molecule inhibitor of LOXL2 ((2-Chloropyridin-4-yl) methanamine hydrochloride) significantly decreased the invasive ability of cervical cancer by reversing the process of LOXL2-induced EMT. In summary, LOXL2 may be a promising diagnostic and therapeutic biomarker for cervical cancer, and its small molecule inhibitor may be an effective anti-tumor drug.

Everolimus (RAD001) combined with programmed death-1 (PD-1) blockade enhances radiosensitivity of cervical cancer and programmed death-ligand 1 (PD-L1) expression by blocking the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR)/S6 kinase 1 (S6K1) pathway

Cervical cancer (CC) is the 4^th most prevalent malignancy in females. This study explored the mechanism of everolimus (RAD001) combined with programmed death-1 (PD-1) blockade on radiosensitivity by phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway and autophagy in CC cells. Low-radiosensitive CaSki cells were selected as study objects. After RAD001 treatment, PI3K/AKT/mTOR pathway activation, autophagy, migration and invasion abilities, autophagy-related proteins (LC3-I, LC3-II, and p62), and PD-L1 expression in CC cells were detected. After triple treatment of radiotherapy (RT), RAD001, and PD-1 blockade to the CC mouse models, tumor weight and volume were recorded. Ki67 expression, the number of CD8 + T cells, and the ability to produce IFN-γ and TNF-α in tumor tissues were determined. RAD001 promoted autophagy by repressing PI3K/AKT/mTOR pathway, augmented RT-induced apoptosis, and weakened migration and invasion, thereby increasing CC cell radiosensitivity. RAD001 elevated RT-induced PD-L1 level. RT combined with RAD001 and PD-1 blockade intensified the inhibitory effect of RT on tumor growth, reduced the amount of Ki67-positive cells, enhanced radiosensitivity of CC mice, and increased the quantity and killing ability of CD8 + T cells. Briefly, RAD001 combined with PD-1 blockade increases radiosensitivity of CC by impeding the PI3K/AKT/mTOR pathway and potentiating cell autophagy.

A Pan-Cancer Bioinformatic Analysis of RAD51 Regarding the Values for Diagnosis, Prognosis, and Therapeutic Prediction

Background

RAD51, a critical protein for DNA repairment, has been found to associate with multiple cancer types, but, so far, a systematic pan-cancer analysis of RAD51 has not been done yet.

Methods

Data were obtained from multiple open databases and genetic alteration, gene expression, survival association, functional enrichment, stemness, mutation association, immunity association, and drug therapy association of RAD51were analyzed. A prognostic model of RAD51 for overall glioma was constructed as an example application of RAD51 as a biomarker.

Results

RAD51 was overexpressed in 28 types of cancers and was associated with worse overall survival in 11 cancer types. RAD51 correlated genes were enriched in cell cycle terms. RAD51 was associated with cancer stemness, tumor mutational burden, and multiple immunomodulators in different cancer types. RAD51 expression was different across immune subtypes in 11 cancer types. RAD51 was closely associated with cancer immune microenvironments in some cancer types. Proliferating T cells was the cell type that expressed highest RAD51 across most of the cancer samples analyzed. RAD51 expression had an AUC of over 0.5 in 12 of the 23 ICB subcohorts. The Tumor Immune Dysfunction and Exclusion of 9 cancer types were different between RAD51 high and low groups. RAD51 expression showed negative correlations with the sensitivity of most drugs. A prognostic nomogram was constructed with a high confidence.

Conclusion

RAD51 is a clinical valuable biomarker for multiple cancer types, regarding its potential power for diagnosis, prognosis, and therapeutic prediction.

1α,25(OH)2D3(VD3) promotes Raddeanin A-induced anti-proliferative effects on HeLa cell apoptosis and autophagy through negative regulation of HPV18E6-E7/PD-L1/VDR axis

Raddeanin A (RA) has indicated suppressive effects on various human tumor cells, and insufficient vitamin D was associated with human papillomavirus (HPV) persistence and gynecological tumors. However, combined effects of RA and vitamin D on HPV-positive cells remain elusive. Herein, we aimed to investigate the combined effects of RA and 1ɑ,25(OH)₂D₃ (VD3) on cellular viability and modulation of HPV18E6/E7, programmed cell death 1 ligand (PD-L1) and vitamin D receptor (VDR) expression in HeLa cells in vitro. HeLa cells were treated with RA alone or VD3 combined with RA. Cell viability was measured using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT), and apoptosis was detected by flow cytometry. Real-time PCR (qRT-PCR) and Western blot were used to determine the gene/protein expression levels. The autophagosomes were observed by Transmission electron microscopy (TEM). The result showed that cell viability was inhibited by RA, and apoptosis in HeLa cells treated with RA was elevated accordingly. The expression of Bax, Cleaved-caspase-3, Cleaved-caspase-9 and Cleaved-PARP increased, and Bcl-2 decreased. The autophagy was induced by RA, as evidenced by elevated autophagosomes and the increased LC3-II/I ratio and Beclin-1. The expression of HPV18E6/E7, PD-L1 and VDR was reduced by RA. Moreover, RA combined with VD3 had a stronger effect on HeLa cells than RA alone. In conclusion, RA inhibits HeLa proliferation and induces apoptosis and autophagy via suppressing HPV18E6/E7, PD-L1 and VDR, and VD3 showed reinforced effects of RA on HeLa cells. Therefore, combined usage of VD3 with RA might be a potential novel immunotherapy strategy for HPV-related diseases.

Current Progress and Future Perspectives of Immune Checkpoint in Cancer and Infectious Diseases

The inhibitory regulators, known as immune checkpoints, prevent overreaction of the immune system, avoid normal tissue damage, and maintain immune homeostasis during the antimicrobial or antiviral immune response. Unfortunately, cancer cells can mimic the ligands of immune checkpoints to evade immune surveillance. Application of immune checkpoint blockade can help dampen the ligands expressed on cancer cells, reverse the exhaustion status of effector T cells, and reinvigorate the antitumor function. Here, we briefly introduce the structure, expression, signaling pathway, and targeted drugs of several inhibitory immune checkpoints (PD-1/PD-L1, CTLA-4, TIM-3, LAG-3, VISTA, and IDO1). And we summarize the application of immune checkpoint inhibitors in tumors, such as single agent and combination therapy and adverse reactions. At the same time, we further discussed the correlation between immune checkpoints and microorganisms and the role of immune checkpoints in microbial-infection diseases. This review focused on the current knowledge about the role of the immune checkpoints will help in applying immune checkpoints for clinical therapy of cancer and other diseases.

Case Report: A Case Report and Literature Review on Severe Bullous Skin Reaction Induced by anti-PD-1 Immunotherapy in a Cervical Cancer Patient

Background: Anti-programmed cell death protein 1 (PD-1) has been successfully used in carcinomas treatment. However, it causes significant adverse effects (AEs), including cutaneous reactions, particularly the life-threatening severe bullous skin reactions (SBSR) and toxic epidermal necrolysis (TEN).

Case summary: Herein, we described for the first time a case report of SBSR induced by anti-PD-1 therapy in a cervical cancer patient. In addition, we revised existing literature on anti-PD-1 induced cutaneous reactions. We reported a cervical cancer patient who was treated with four successive cycles of Sintilimab and Toripalimab injections and developed systemic rashes, bullae, and epidermal desquamation, which worsened and led to infection, eventually causing death after being unresponsive to aggressive treatments.

Conclusion: Anti-PD-1 antibodies commonly cause skin toxicity effects, some of which may be deadly. Therefore, healthcare providers should observe early symptoms and administer proper treatment to prevent aggravation of symptoms.

Metabolism-Relevant Molecular Classification Identifies Tumor Immune Microenvironment Characterization and Immunotherapeutic Effect in Cervical Cancer

Cervical cancer (CESC) is a gynecologic malignant tumor associated with high incidence and mortality rates because of its distinctive management complexity. Herein, we characterized the molecular features of CESC based on the metabolic gene expression profile by establishing a novel classification system and a scoring system termed as METAscore. Integrative analysis was performed on human CESC samples from TCGA dataset. Unsupervised clustering of RNA sequencing data on 2,752 formerly described metabolic genes identified three METAclusters. These METAclusters for overall survival time, immune characteristics, metabolic features, transcriptome features, and immunotherapeutic effectiveness existed distinct differences. Then we analyzed 207 DEGs among the three METAclusters and as well identified three geneclusters. Correspondingly, these three geneclusters also differently expressed among the aforementioned features, supporting the reliability of the metabolism-relevant molecular classification. Finally METAscore was constructed which emerged as an independent prognostic biomarker, related to CESC transcriptome features, metabolic features, immune characteristics, and linked to the sensitivity of immunotherapy for individual patient. These findings depicted a new classification and a scoring system in CESC based on the metabolic pattern, thereby furthering the understanding of CESC genetic signatures and aiding in the prediction of the effectiveness to anticancer immunotherapies.

Nanomedicine-mediated optimization of immunotherapeutic approaches in cervical cancer

Cervical cancer shows immense complexity at the epigenetic, genetic and cellular levels, limiting conventional treatment. Immunotherapy has revolutionized nanomedicine and rejuvenated the field of tumor immunology. Although several immunotherapeutic approaches have shown favorable clinical responses, their efficacies vary, with subsets of patients benefitting. The success of cancer immunotherapy requires the enhancement of cytokines and antitumor effector cell production and activation. Recently, the feasibility of nanoparticle-based cytokine approaches in tumor immunotherapy has been highlighted. Immunotherapeutic nanoparticle-based platforms form a novel strategy enabling researchers to co-deliver immunomodulatory agents, target tumors, improve pharmacokinetics and minimize collateral toxicity to healthy cells. This review looks at the potential of immunotherapy and nanotechnologically enhanced immunotherapeutic approaches for cervical cancer.

CCR7 Has Potential to Be a Prognosis Marker for Cervical Squamous Cell Carcinoma and an Index for Tumor Microenvironment Change

The tumor microenvironment (TME) has an essential role in the development of cervical squamous cell carcinoma (CSCC); however, the dynamic role of the stromal and immune cells is still unclear in TME. We downloaded data from The Cancer Genome Atlas (TCGA) database and applied ESTIMATE and CIBERSORT algorithms to measure the quantity of stromal and immune cells and the composition of tumor-infiltrating immune cell (TIC) in 253 CSCC cases. The protein-protein interaction (PPI) network and Cox regression analysis presented the differentially expressed genes (DEGs). Then, C-C chemokine receptor type 7 (CCR7) was screened out as a prognostic marker by the univariate Cox and intersection analysis of PPI. Further analysis showed a positive correlation between the expression of CCR7 and the survival of CSCC patients. The result of the Gene Set Enrichment Analysis (GSEA) of genes in the high CCR7 expression group displayed a predominant enrichment in immune-related pathways. An enrichment in metabolic activities was observed in the low CCR7 expression group. CIBERSORT analysis showed a positive correlation between Plasma cells, CD8⁺ T cells, and regulatory T cells and the CCR7 expression, suggesting that CCR7 might play a crucial role in maintaining the immunological dominance status for TME. Therefore, the expression level of CCR7 might help predict the survival of CSCC cases and be an index that the status of TME transitioned from immunological dominance to metabolic activation, which presented a new insight into the treatment of CSCC.

In Vivo Evaluation and Dosimetry Estimate for a High Affinity Affibody PET Tracer Targeting PD-L1

PURPOSE

In vivo imaging of programmed death ligand 1 (PD-L1) during immunotherapy could potentially monitor changing PD-L1 expression and PD-L1 expression heterogeneity within and across tumors. Some protein constructs can be used for same-day positron emission tomography (PET) imaging. Previously, we evaluated the PD-L1-targeting Affibody molecule [¹⁸F]AlF-NOTA-Z_{PD-L1_1} as a PET tracer in a mouse tumor model of human PD-L1 expression. In this study, we evaluated the affinity-matured Affibody molecule Z_{PD-L1_4}, to determine if improved affinity for PD-L1 resulted in increased in vivo targeting of PD-L1.

PROCEDURES

Z_{PD-L1_4} was conjugated with NOTA and radiolabeled with either [¹⁸F]AlF or ⁶⁸Ga. [¹⁸F]AlF-NOTA-Z_{PD-L1_4} and [⁶⁸Ga]NOTA-Z_{PD-L1_4} were evaluated in immunocompromised mice with LOX (PD-L1+) and SUDHL6 (PD-L1-) tumors with PET and ex vivo biodistribution measurements. In addition, whole-body PET studies were performed in rhesus monkeys to predict human biodistribution in a model with tracer binding to endogenous PD-L1, and to calculate absorbed radiation doses.

RESULTS

Ex vivo biodistribution measurements showed that both tracers had > 25 fold higher accumulation in LOX tumors than SUDHL6 ([¹⁸F]AlF-NOTA-Z_{PD-L1_4}: LOX: 8.7 ± 0.7 %ID/g (N = 4) SUDHL6: 0.2 ± 0.01 %ID/g (N = 6), [⁶⁸Ga]NOTA-Z_{PD-L1_4}: LOX: 15.8 ± 1.0 %ID/g (N = 6) SUDHL6: 0.6 ± 0.1 %ID/g (N = 6)), considerably higher than Z_{PD-L1_1}. In rhesus monkeys, both PET tracers showed fast clearance through kidneys and low background signal in the liver ([¹⁸F]AlF-NOTA-Z_{PD-L1_4}: 1.26 ± 0.13 SUV, [⁶⁸Ga]NOTA-Z_{PD-L1_4}: 1.11 ± 0.06 SUV). PD-L1-expressing lymph nodes were visible in PET images, indicating in vivo PD-L1 targeting. Dosimetry estimates suggest that both PET tracers can be used for repeated clinical studies, although high kidney accumulation may limit allowable radioactive doses.

CONCLUSIONS

[¹⁸F]AlF-NOTA-Z_{PD-L1_4} and [⁶⁸Ga]NOTA-Z_{PD-L1_4} are promising candidates for same-day clinical PD-L1 PET imaging, warranting clinical evaluation. The ability to use either [¹⁸F] or [⁶⁸Ga] may expand access to clinical sites.

Prognostic Implications of Immune-Related Genes' (IRGs) Signature Models in Cervical Cancer and Endometrial Cancer

Cervical cancer and endometrial cancer remain serious threats to women's health. Even though some patients can be treated with surgery plus chemoradiotherapy as a conventional option, the overall efficacy is deemed unsatisfactory. As such, the development for new treatment approaches is truly necessary. In recent years, immunotherapy has been widely used in clinical practice and it is an area of great interest that researchers are keeping attention on. However, a thorough immune-related genes (IRGs) study for cervical cancer and endometrial cancer is still lacking. We therefore aim to make a comprehensive evaluation of IRGs through bioinformatics and large databases, and also investigate the relationship between the two types of cancer. We reviewed the transcriptome RNAs of IRGs and clinical data based on the TCGA database. Survival-associated IRGs in cervical/endometrial cancer were identified using univariable and multivariable Cox proportional-hazard regression analysis for developing an IRG signature model to evaluate the risk of patients. In the end, this model was validated based on the enrichment analyses through GO, KEGG, and GSEA pathways, Kaplan-Meier survival curve, ROC curves, and immune cell infiltration. Our results showed that out of 25/23 survival-associated IRGs for cervical/endometrial cancer, 13/12 warranted further examination by multivariate Cox proportional-hazard regression analysis and were selected to develop an IRGs signature model. As a result, enrichment analyses for high-risk groups indicated main enriched pathways were associated with tumor development and progression, and statistical differences were found between high-risk and low-risk groups as shown by Kaplan-Meier survival curve. This model could be used as an independent measure for risk assessment and was considered relevant to immune cell infiltration, but it had nothing to do with clinicopathological characteristics. In summary, based on comprehensive analysis, we obtained the IRGs signature model in cervical cancer (LTA, TFRC, TYK2, DLL4, CSK, JUND, NFATC4, SBDS, FLT1, IL17RD, IL3RA, SDC1, PLAU) and endometrial cancer (LTA, PSMC4, KAL1, TNF, SBDS, HDGF, LTB, HTR3E, NR2F1, NR3C1, PGR, CBLC), which can effectively evaluate the prognosis and risk of patients and provide justification in immunology for further researches.

High-Risk HPV Oncoproteins and PD-1/PD-L1 Interplay in Human Cervical Cancer: Recent Evidence and Future Directions

Cervical cancer is the fourth most common malignancy in women worldwide and a leading cause of cancer-related mortality in developing countries. Important etiological factors in this cancer are high-risk human papillomaviruses (HPV), as roughly 96% of cervical cancer cases are positive for these oncoviruses. On the other hand, it has been recently pointed out that E6/E7 oncoproteins of high-risk HPV can upregulate the programmed cell death-1/programmed cell death-ligand 1 (PD-1/PD-L1) axis. Likewise, several recent reports showed that checkpoint blockades targeting PD-1/PD-L1 pathways have achieved efficient clinical responses via suppressing cancer progression and improving survival in several types of human cancers including metastatic cervical cancer. In this review, we summarize recent advances in our understanding of the PD-1/PD-L1 signaling pathway and its interaction with high-risk HPV and their oncoproteins, which could have an important impact on the management of HPV-associated cancers including cervical.

iTRAQ-based quantitative proteomic analysis of the inhibition of cervical cancer cell invasion and migration by metformin

In recent years the anti-diabetic drug metformin has been shown to inhibit tumor growth, but the underlying mechanism is unclear. Our previous results showed that metformin can destroy the sponge effect of long-chain non-coding RNA MALAT1/miR-142-3p and inhibit the proliferation of cervical cancer cells. Metformin can inhibit the PI3K/Akt signaling pathway and synergizes with Nelfinavir to inhibit the proliferation and invasion of cervical cancer cells. In this study, we used iTRAQ-based proteomics, mass spectrometry-based targeted proteomics, immunoblotting, and bioinformatics to analyze the molecular mechanism by which metformin inhibits the proliferation and invasion of cervical cancer cells. We found that 53 proteins were differentially expressed in cervical cancer cells after metformin treatment, of which 20 were up-regulated and 33 were down-regulated. Bioinformatics analysis showed that the 53 differentially expressed proteins are negative regulators of receptor signaling that inhibit cell growth and are mainly enriched in cell growth and apoptosis signaling pathways. We performed PRM verification on 11 of the differentially expressed proteins and found that they were all associated with apoptosis. We also found that metformin up-regulated the expression of the tumor suppressor IGFBP7 to inhibit the proliferation and invasion of cervical cancer cells. Our results indicate that metformin mainly regulates the insulin signaling pathway and interferes with cell proliferation and apoptosis to inhibit proliferation and invasion of cervical cancer cells. These differentially expressed proteins may become new targets for the treatment of cervical cancer.