Polygenic risk score of non‐melanoma skin cancer predicts post‐transplant skin cancer across multiple organ types

Improving liver transplant outcomes with transplant-omics and network biology

PURPOSE OF REVIEW

Molecular omics data is increasingly ubiquitous throughout medicine. In organ transplantation, recent large-scale research efforts are generating the 'transplant-ome' - the entire set of molecular omics data, including the genome, transcriptome, proteome, and metabolome. Importantly, early studies in anesthesiology have demonstrated how perioperative interventions alter molecular profiles in various patient populations. The next step for anesthesiologists and intensivists will be to tailor perioperative care to the transplant-ome of individual liver transplant patients.

RECENT FINDINGS

In liver transplant patients, elements of the transplant-ome predict complications and point to novel interventions. Importantly, molecular profiles of both the donor organ and recipient contribute to this risk, and interventions like normothermic machine perfusion influence these profiles. As we can now measure various omics molecules simultaneously, we can begin to understand how these molecules interact to form molecular networks and emerging technologies offer noninvasive and continuous ways to measure these networks throughout the perioperative period. Molecules that regulate these networks are likely mediators of complications and actionable clinical targets throughout the perioperative period.

SUMMARY

The transplant-ome can be used to tailor perioperative care to the individual liver transplant patient. Monitoring molecular networks continuously and noninvasively would provide new opportunities to optimize perioperative management.

Silencing of Dicer enhances dacarbazine resistance in melanoma cells by inhibiting ADSL expression

Dacarbazine (DTIC) is the primary first-line treatment for advanced-stage metastatic melanoma; thus, DTIC resistance is poses a major challenge. Therefore, investigating the mechanism underlying DTIC resistance must be investigated. Dicer, a type III cytoplasmic endoribonuclease, plays a pivotal role in the maturation of miRNAs. Aberrant Dicer expression may contribute to tumor progression, clinical aggressiveness, and poor prognosis in various tumors. Dicer inhibition led to a reduction in DTIC sensitivity and an augmentation in stemness in melanoma cells. Clinical analyses indicated a low Dicer expression level as a predictor of poor prognosis factor. Metabolic alterations in tumor cells may interfere with drug response. Adenylosuccinate lyase (ADSL) is a crucial enzyme in the purine metabolism pathway. An imbalance in ADSL may interfere with the therapeutic efficacy of drugs. We discovered that DTIC treatment enhanced ADSL expression and that Dicer silencing significantly reduced ADSL expression in melanoma cells. Furthermore, ADSL overexpression reversed Dicer silencing induced DTIC resistance and cancer stemness. These findings indicate that Dicer-mediated ADSL regulation influences DTIC sensitivity and stemness in melanoma cells.

Interventions After First Post-Transplant Cutaneous Squamous Cell Carcinoma: A Proposed Decision Framework

Cutaneous squamous cell carcinoma (CSCC) is a major cause of morbidity and mortality after organ transplant. Many patients subsequently develop multiple CSCC following a first CSCC, and the risk of metastasis and death is significantly increased compared to the general population. Post-transplant CSCC represents a disease at the interface of dermatology and transplant medicine. Both systemic chemoprevention and modulation of immunosuppression are frequently employed in patients with multiple CSCC, yet there is little consensus on their use after first CSCC to reduce risk of subsequent tumors. While relatively few controlled trials have been undertaken, extrapolation of observational data suggests the most effective interventions may be at the time of first CSCC. We review the need for intervention after a first post-transplant CSCC and evidence for use of various approaches as secondary prevention, before discussing barriers preventing engagement with this approach and finally highlight areas for future research. Close collaboration between specialties to ensure prompt deployment of these interventions after a first CSCC may improve patient outcomes.

De Novo Skin Neoplasms in Liver-Transplanted Patients: Single-Center Prospective Evaluation of 105 Cases

Background and Objectives: Solid-organ transplant recipients (SOTRs) are notably considered at risk for developing cutaneous malignancies. However, most of the existing literature is focused on kidney transplant-related non-melanoma skin cancers (NMSCs). Conflicting data have been published so far on NMSC incidence among liver transplant recipients (LTRs), and whether LTRs really should be considered at lower risk remains controversial. The aim of the present study was to prospectively collect data on the incidence of cutaneous neoplasms in an LTR cohort. Materials and Methods: All LTRs transplanted at the Hepato-Pancreato-Biliary Surgery and Liver Transplantation Unit of Modena University Hospital from October 2015 to June 2021 underwent a post-transplant periodic skin check at the Dermatology Unit according to our institutional integrated care pathway. Data on the presence of cutaneous malignant and premalignant lesions were collected at every timepoint. Results: A total of 105 patients were enrolled in the present study. Nearly 15% of the patients developed cutaneous cancerous and/or precancerous lesions during the follow-up period. Almost half of the skin cancerous lesions were basal cell carcinomas. Actinic keratoses (AKs) were observed in six patients. Four patients developed in situ squamous cell carcinomas, and one patient was diagnosed with stage I malignant melanoma. Otherwise, well-established risk factors for the occurrence of skin tumors, such as skin phototype, cumulative sun exposure, and familial history of cutaneous neoplasms, seemed to have no direct impact on skin cancer occurrence in our cohort, as well as an immunosuppressive regimen and the occurrence of non-cutaneous neoplasms. Conclusions: Close dermatological follow-up is crucial for LTRs, and shared protocols of regular skin checks in this particular subset of patients are needed in transplant centers.

A pharmacogenomic assessment of psychiatric adverse drug reactions to levetiracetam

OBJECTIVE

Levetiracetam (LEV) is an effective antiseizure medicine, but 10%-20% of people treated with LEV report psychiatric side-effects, and up to 1% may have psychotic episodes. Pharmacogenomic predictors of these adverse drug reactions (ADRs) have yet to be identified. We sought to determine the contribution of both common and rare genetic variation to psychiatric and behavioral ADRs associated with LEV.

METHODS

This case-control study compared cases of LEV-associated behavioral disorder (n = 149) or psychotic reaction (n = 37) to LEV-exposed people with no history of psychiatric ADRs (n = 920). All samples were of European ancestry. We performed genome-wide association study (GWAS) analysis comparing those with LEV ADRs to controls. We estimated the polygenic risk scores (PRS) for schizophrenia and compared cases with LEV-associated psychotic reaction to controls. Rare variant burden analysis was performed using exome sequence data of cases with psychotic reactions (n = 18) and controls (n = 122).

RESULTS

Univariate GWAS found no significant associations with either LEV-associated behavioural disorder or LEV-psychotic reaction. PRS analysis showed that cases of LEV-associated psychotic reaction had an increased PRS for schizophrenia relative to contr ols (p = .0097, estimate = .4886). The rare-variant analysis found no evidence of an increased burden of rare genetic variants in people who had experienced LEV-associated psychotic reaction relative to controls.

SIGNIFICANCE

The polygenic burden for schizophrenia is a risk factor for LEV-associated psychotic reaction. To assess the clinical utility of PRS as a predictor, it should be tested in an independent and ideally prospective cohort. Larger sample sizes are required for the identification of significant univariate common genetic signals or rare genetic signals associated with psychiatric LEV ADRs.

Cancer Screening in Solid Organ Transplant Recipients: A Focus on Screening Liver, Lung, and Kidney Recipients for Cancers Related to the Transplanted Organ

Over the last few decades, the life expectancy of solid organ transplant recipients (SOTRs) has improved significantly. With SOTRs living longer, more recipients are dying from cancer. There is a reported 2- to 3-fold increased risk of cancer-specific mortality in SOTRs compared with the general population. Cancer in an SOTR can be de novo, recurrent, or donor-derived. Cancer screening in this population is crucial, as early detection and treatment may improve outcomes. In the absence of randomized controlled trials dedicated to SOTRs, clinicians rely on clinical practice guidelines from regional and national transplant societies; however, these may vary considerably across jurisdictions and transplanted organ. At present, no widely accepted consensus exists for cancer screening protocols in SOTRs, particularly with regard to screening for malignancy related to transplanted organ. Some SOTRs may be at higher risk of malignancies within the allograft. This is particularly the case in lung and liver recipients, though less common in kidney recipients who are at increased risk of developing renal cell cancer in their native kidneys. This increased risk has not been uniformly incorporated into screening recommendations for SOTRs. In this review, we summarize the cancer screening recommendations for SOTRs from various transplant organizations based on transplanted organ. This review also discusses the complexity and controversies surrounding screening of cancer in the allograft and future avenues to improve cancer detection in this context. More studies specific to SOTRs are required to form generalizable and evidence-based cancer screening guidelines, particularly with respect to cancer screening in the allograft.

Polygenic Risk Scores Stratify Keratinocyte Cancer Risk among Solid Organ Transplant Recipients with Chronic Immunosuppression in a High Ultraviolet Radiation Environment

Solid organ transplant recipients (SOTRs) have elevated risks for basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), especially in high UVR environments. We assessed whether polygenic risk scores can improve the prediction of BCC and SCC risks and multiplicity over and above the traditional risk factors in SOTRs in a high UV setting. We built polygenic risk scores for BCC (n = 594,881) and SCC (n = 581,431) using UK Biobank and 23andMe datasets, validated them in the Australian QSkin Sun and Health Study cohort (n > 6,300), and applied them in SOTRs in the skin tumor in allograft recipients cohort from Queensland, Australia, a high UV environment. About half of the SOTRs with a high genetic risk developed BCC (absolute risk = 45.45%, 95% confidence interval = 33.14-58.19%) and SCC (absolute risk = 44.12%, 95% confidence interval = 32.08-56.68%). For both cancers, SOTRs in the top quintile were at >3-fold increased risk relative to those in the bottom quintile. The respective polygenic risk scores improved risk predictions by 2% for BCC (area under the curve = 0.77 vs. 0.75, P = 0.0691) and SCC (area under the curve = 0.84 vs. 0.82, P = 0.0260), over and above the established risk factors, and 19.03% (for BCC) and 18.10% (for SCC) of the SOTRs were reclassified in a high/medium/low risk scenario. The polygenic risk scores also added predictive accuracy for tumor multiplicity (BCC R2 = 0.21 vs. 0.19, P = 3.2 × 10-3; SCC R2 = 0.30 vs. 0.27, P = 4.6 × 10-4).

Biological Predictors of De Novo Tumors in Solid Organ Transplanted Patients During Oncological Surveillance: Potential Role of Circulating TERT mRNA

Background

De novo tumors are a major cause of morbidity and mortality after long-term solid organ transplantation. Chronic immunosuppression strongly affects solid organ transplanted (SOT) patients' immune system by promoting immune evasion strategies and reactivations of viruses with oncogenic potential, ultimately leading to cancer onset. In this scenario, an oncological Surveillance Protocol integrated with biobanking of peripheral blood samples and evaluation of immunovirological and molecular parameters was activated for SOT patients at CRO-IRCCS Aviano, with the aim of identifying suitable biomarkers of cancer development.

Methods

An exploratory longitudinal study was designed based on two serial peripheral blood samples collected at least three months apart. Forty nine SOT patients were selected and stratified by tumor onset during follow-up. Spontaneous T-cell responses to EBV, CMV and tumor associated antigens, EBV-DNA and CMV-DNA loads, and circulating TERT mRNA levels were investigated.

Results

Significantly higher levels of circulating TERT mRNA were observed 3.5-23.5 months before and close to the diagnosis of cancer as compared to tumor-free patients. Plasmatic TERT mRNA levels >97.73 copies/mL at baseline were significantly associated with the risk of developing de novo tumors (HR=4.0, 95%C.I. = 1.4-11.5, p=0.01). In particular, the risk significantly increased by 4% with every ten-unit increment in TERT mRNA (HR=1.04, 95%C.I. = 1.01-1.07, p=0.01).

Conclusions

Although obtained in an exploratory study, our data support the importance of identifying early biomarkers of tumor onset in SOT patients useful to modulate the pace of surveillance visits.