Subcutaneous administration of a novel TRPM8 antagonist reverses cold hypersensitivity while attenuating the drop in core body temperature.

BACKGROUND AND PURPOSE: We extend the characterization of the TRPM8 antagonist VBJ103 with tests of selectivity, specificity and distribution, therapeutic efficacy of systemic administration against oxaliplatin-induced cold hyperalgesia and the impact of systemic administration on core body temperature (CBT). EXPERIMENTAL APPROACH: Selectivity at human TRPA1 and TRPV1 as well as in vitro safety profiling was determined. Effects of systemic administration of VBJ103 were evaluated in a model of oxaliplatin-induced cold hyperalgesia. Both peripheral and centrally mediated effects of VBJ103 on CBT were assessed with radiotelemetry. KEY RESULTS: VBJ103 had no antagonist activity at TRPV1 and TRPA1, but low potency TRPA1 activation. The only safety liability detected was partial inhibition of the dopamine transporter (DAT). VBJ103 delivered subcutaneously dose-dependently attenuated cold hypersensitivity in oxaliplatin-treated mice at 3, 10 and 30 mg·kg-1 (n = 7, P < 0.05). VBJ103 (30 mg·kg-1) antinociception was influenced by neither the TRPA1 antagonist HC-030031 nor the DAT antagonist GBR12909. Subcutaneous administration of VBJ103 (3, 10 and 30 mg·kg-1, but not 100 or 300 mg·kg-1, n = 7) decreased CBT (2°C). Intraperitoneal (i.p.) administration of VBJ103 (3, 10 and 30 mg·kg-1) dose-dependently decreased CBT to an extent larger than that detected with subcutaneous administration. Intracerebroventricular (i.c.v.) administration (306 nmol/1 µL; n = 5) did not alter CBT. CONCLUSIONS AND IMPLICATIONS: We achieve therapeutic efficacy with subcutaneous administration of a novel TRPM8 antagonist that attenuates deleterious influences on CBT, a side effect that has largely prevented the translation of TRPM8 as a target.

Restricted access and advanced disease in post-pandemic testicular cancer.

INTRODUCTION: Urologists observed reduced cancer consultations and surgeries during the SARS-CoV-2 pandemic, raising concern about treatment delays. Testicular cancer serves as a particularly sensitive marker of this phenomenon, as the clinical stage of testicular cancer at presentation is predictive of cancer-specific survival. We aimed to investigate whether COVID-related restrictions to primary care access resulted in increased incidence of metastatic germ cell testis cancer. METHODS: A retrospective chart review was conducted on all cases of testicular cancer managed surgically at our center from March 1, 2018, to February 28, 2023. Patients were categorized into temporal cohorts, representing before, during, and following the implementation of COVID-19 public health restrictions in the province of Newfoundland and Labrador. RESULTS: Forty-one cases of testicular germ cell tumors were identified during the study period. The mean age at diagnosis was 40.8 years (standard deviation ±13.7). Demographics did not vary across the cohorts. Clinical stage 3 disease remained stable before and during the pandemic at 10.5% and 9.1% of cases, respectively. In the post-pandemic period, there was an increase to 27.3% (p=0.617). Surgical wait times remained stable across the pandemic (p=0.151). CONCLUSIONS: There was a 16.8% rise in clinical stage III disease from the pre-pandemic to post-pandemic period. Our study failed to identify a statistically significant increase in metastatic testis cancer incidence upon lifting of pandemic restrictions. Further study is necessary to confirm suspicions that pandemic restrictions contributed to increased incidence of metastatic testis cancer.

Impact of the COVID-19 pandemic on diagnosis of renal cell carcinoma and disease stage at presentation.

INTRODUCTION: Renal cell carcinoma (RCC) is often associated with significant morbidity and mortality, with overall survival contingent on multiple factors - most importantly, disease stage at diagnosis. Disruptions in healthcare delivery during the COVID-19 pandemic have resulted in various reported diagnostic and treatment delays, which have had detrimental impacts on malignancies such as RCC. METHODS: Surgically managed cases of RCC at our center were identified using a retrospective chart review of all nephrectomies conducted from March 1, 2018, to February 28, 2023. Examination of disease characteristics in three time period cohorts (before, during, and following the COVID-19 pandemic) was undertaken. Timeframes were consistent with implementation and abolition of public health restrictions in the province of Newfoundland and Labrador. RESULTS: A total of 483 surgically managed RCC cases were identified during the study period. The median age was 65 years (interquartile range [IQR] 56-71), and 62.3% of patients were male. Demographics did not vary across timeframes. Before and during the pandemic, pathologic stage 3 (pT3) disease was reported in 38.9% and 35.4% of cases, respectively, whereas the post-pandemic period saw this presentation in 50.0% of patients. Surgical wait times increased significantly across study timeframes (p=0.003). CONCLUSIONS: The first year following the COVID-19 pandemic saw an 11.1% increase in patients presenting with pT3 RCC. These findings are suggestive of a clinically significant stage migration, which paired with prolonged wait times for surgery, provide critical consideration in the urgency of diagnostic and treatment decisions for RCC in the immediate future.

A population-based analysis of the epidemiology of penile cancer in Newfoundland and Labrador.

INTRODUCTION: Penile cancers are a rare subset of carcinomas accounting for <1% of all diagnosed malignancies. There have been recent reports of increasing incidence globally; however, there is limited Canadian literature pertaining to these neoplasms. The province of Newfoundland and Labrador (NL ) represents an important entity to study, possessing the highest national incidence of cancer, along with a plethora of relevant risk factors for penile cancer. METHODS: A retrospective chart analysis of all patients with a diagnosis of penile cancer in NL between the years of 2006 and 2018 was conducted. The main outcomes included overall incidence, proportion with metastatic disease, tumor demographics, and overall survival (OS ). Incidence among the male population was calculated using Statistics Canada annual reports. RESULTS: An identified 81 cases satisfied the inclusion criteria, with a median age at diagnosis of 65 (interquartile range 20) years. Crude incidence of penile cancer ranged from 1.20-4.27/100 000 males in 2007 and 2010, respectively, while the average age-standardized incidence was 2.34/100 000 males across the study timeframe. Metastatic disease was noted in 17 (21.0%) patients, with a five-year OS of 74% for all penile malignancies, decreasing to 66% in those with invasive squamous cell carcinoma. CONCLUSIONS: The incidence of penile cancer in our population was higher than reported Western jurisdictions and showed frequent rates of metastatic spread. These observations are likely multifactorial, resultant of chronic inflammation paired with high rates of modifiable risk factors and diagnostic delays. An evident need for greater examination and improved reporting of these malignancies in the province was identified.

The Utility of Salvage Radiotherapy for an Inoperable Inguinal Recurrence of Squamous Cell Carcinoma of the Penis.

Penile cancer is a rare genitourinary malignancy for which limited treatment options exist beyond primary surgical resection. Metastatic lymphadenopathy represents a particularly poor prognosis with a lack of literature to suggest the effectiveness of radiation or systemic therapies. Our case documents an inguinal recurrence of penile squamous cell carcinoma not amenable to surgical intervention demonstrating complete response to salvage radiotherapy in the palliative setting. These observations propose the need for further research around the utility of radiotherapy in the management of metastatic penile malignancies.

Malignant Mesothelioma of the Testes with Retroperitoneal Recurrence and Resection in an 80-Year-Old Male and Review of the Literature.

Malignant mesothelioma of the testes is an aggressive, yet rare urogenital malignancy, accounting for an infinitesimally small number of oncologic diagnoses. This infrequent occurrence is accompanied by a relative lack of knowledge surrounding this disease, thus limiting management options beyond surgical intervention. Oftentimes, these malignancies present with a poor prognosis despite early intervention and only worsen in the event of metastatic spread with poor survival and limited response to treatment, if any. Our case documents positive patient outcomes following the use of aggressive surgical intervention in the management of a metastatic testicular mesothelioma. A healthy 80-year-old male with sudden painless testicular swelling requiring radical orchidectomy following failed initial conservative management. Pathologically, the specimen was diagnosed as malignant mesothelioma of the right testis with involvement of the tunica albuginea and tunica vaginalis. Following disease recurrence at 82 years of age, the patient subsequently opted for an open right-sided template non-nerve sparing retroperitoneal lymph node dissection which was undertaken without complication. Malignant mesothelioma of the testes remains an ominous diagnosis with historically poor outcomes and for which surgical intervention remains the mainstay of treatment. The retroperitoneal lymphatic drainage represents the most common route of metastatic spread for testicular tumours; however, retroperitoneal lymph node dissection has rarely been employed in this patient population and never in an individual of this age. Our findings contribute to the growing literature surrounding these rare malignancies and outline the importance of considering both patient autonomy and the clinical picture in disease management.

Characterization of allosteric modulators that disrupt androgen receptor co-activator protein-protein interactions to alter transactivation-Drug leads for metastatic castration resistant prostate cancer.

Three series of compounds were prioritized from a high content screening campaign that identified molecules that blocked dihydrotestosterone (DHT) induced formation of Androgen Receptor (AR) protein-protein interactions (PPIs) with the Transcriptional Intermediary Factor 2 (TIF2) coactivator and also disrupted preformed AR-TIF2 PPI complexes; the hydrobenzo-oxazepins (S1), thiadiazol-5-piperidine-carboxamides (S2), and phenyl-methyl-indoles (S3). Compounds from these series inhibited AR PPIs with TIF2 and SRC-1, another p160 coactivator, in mammalian 2-hybrid assays and blocked transcriptional activation in reporter assays driven by full length AR or AR-V7 splice variants. Compounds inhibited the growth of five prostate cancer cell lines, with many exhibiting differential cytotoxicity towards AR positive cell lines. Representative compounds from the 3 series substantially reduced both endogenous and DHT-enhanced expression and secretion of the prostate specific antigen (PSA) cancer biomarker in the C4-2 castration resistant prostate cancer (CRPC) cell line. The comparatively weak activities of series compounds in the H3-DHT and/or TIF2 box 3 LXXLL-peptide binding assays to the recombinant ligand binding domain of AR suggest that direct antagonism at the orthosteric ligand binding site or AF-2 surface respectively are unlikely mechanisms of action. Cellular enhanced thermal stability assays (CETSA) indicated that compounds engaged AR and reduced the maximum efficacy and right shifted the EC50 of DHT-enhanced AR thermal stabilization consistent with the effects of negative allosteric modulators. Molecular docking of potent representative hits from each series to AR structures suggest that S1-1 and S2-6 engage a novel binding pocket (BP-1) adjacent to the orthosteric ligand binding site, while S3-11 occupies the AR binding function 3 (BF-3) allosteric pocket. Hit binding poses indicate spaces and residues adjacent to the BP-1 and BF-3 pockets that will be exploited in future medicinal chemistry optimization studies. Small molecule allosteric modulators that prevent/disrupt AR PPIs with coactivators like TIF2 to alter transcriptional activation in the presence of orthosteric agonists might evade the resistance mechanisms to existing prostate cancer drugs and provide novel starting points for medicinal chemistry lead optimization and future development into therapies for metastatic CRPC.

A quality assurance review of penile cancer diagnostic delays and stage at presentation during the COVID-19 pandemic.

INTRODUCTION: Penile carcinomas represent a rare malignancy associated with significant psychosocial impacts that deter afflicted individuals from seeking medical attention, thus, worsening prognosis. Following the dramatic shift in healthcare delivery to virtual platforms, it is suspected that prevalent psychosocial impacts have been further compounded by the COVID-19 pandemic, resulting in several late-stage presentations and engendering poorer outcomes. METHODS: A retrospective chart review of surgically managed cases of penile cancer was conducted from January 2020 to June 2022 to identify patients that may have been unduly impacted by the COVID-19 pandemic. Included cases were analyzed in quantifying diagnostic and treatment delays, along with patient outcomes. Relevant epidemiological and pathological markers were also examined. RESULTS: Ten patients met the inclusion criteria. Average time delay from first complaint of a penile lesion to surgical management was 75 days, with 60% of patients experiencing a time delay of two months or more. The average delay from first complaint to diagnosis was 62 days in 2020 and 18 days in 2021. Advanced-stage disease was present in six (60%) individuals at presentation, while four (40%) patients perished during the study period. CONCLUSIONS: In cases of concern for penile malignancy, virtual care cannot replace the necessity of physical exams in preventing diagnostic and treatment delays. The present study further highlights the necessity of initial physical examination of penile abnormalities in preventing fatal outcomes for those afflicted. Such consideration warrants urgent examination of referred males with genital abnormalities to prevent further exacerbation of delays.

A Complex Case of Pregnancy-related Left Main Stem Spontaneous Coronary Artery Dissection.

Spontaneous coronary artery dissection (SCAD) is a less common cause of acute coronary syndrome. Pregnancy-related SCAD is uncommon, but often presents with a more severe phenotype. This report describes a 30-year-old woman with an anterior ST elevation MI, presenting 1 day postpartum. Left main stem (LMS) SCAD with extensive intramural haematoma (IMH) and resultant LMS occlusion was confirmed by angiography and intravascular imaging. Given the extent of disease, the patient underwent emergency cardiac surgery. Coronary flow was initially improved by decompressing the IMH using cutting balloons. The coronary wires were successfully left in situ during transfer in an effort to both maintain flow and allow the surgeon to identify true LMS. Ideally, SCAD can be managed conservatively given the risk of intervention worsening IMH, and hence myocardial ischaemia/MI. However, emergency revascularisation is indicated in cases of persistent ischaemia. This case demonstrates percutaneous therapies to bridge towards and help with subsequent surgical revascularisation.

Eating in a losing cause: limited benefit of modified macronutrient consumption following infection in the oriental cockroach Blatta orientalis.

BACKGROUND: Host-pathogen interactions can lead to dramatic changes in host feeding behaviour. One aspect of this includes self-medication, where infected individuals consume substances such as toxins or alter their macronutrient consumption to enhance immune competence. Another widely adopted animal response to infection is illness-induced anorexia, which is thought to assist host immunity directly or by limiting the nutritional resources available to pathogens. Here, we recorded macronutrient preferences of the global pest cockroach, Blatta orientalis to investigate how shifts in host macronutrient dietary preference and quantity of carbohydrate (C) and protein (P) interact with immunity following bacterial infection. RESULTS: We find that B. orientalis avoids diets enriched for P under normal conditions, and that high P diets reduce cockroach survival in the long term. However, following bacterial challenge, cockroaches significantly reduced their overall nutrient intake, particularly of carbohydrates, and increased the relative ratio of protein (P:C) consumed. Surprisingly, these behavioural shifts had a limited effect on cockroach immunity and survival, with minor changes to immune protein abundance and antimicrobial activity between individuals placed on different diets, regardless of infection status. CONCLUSIONS: We show that cockroach feeding behaviour can be modulated by a pathogen, resulting in an illness-induced anorexia-like feeding response and a shift from a C-enriched to a more P:C equal diet. However, our results also indicate that such responses do not provide significant immune protection in B. orientalis, suggesting that the host's dietary shift might also result from random rather than directed behaviour. The lack of an apparent benefit of the shift in feeding behaviour highlights a possible reduced importance of diet in immune regulation in these invasive animals, although further investigations employing pathogens with alternative infection strategies are warranted.

Detection and impact of hypoxic regions in multicellular tumor spheroid cultures formed by head and neck squamous cell carcinoma cells lines.

In solid tumors like head and neck cancer (HNC), chronic and acute hypoxia have serious adverse clinical consequences including poorer overall patient prognosis, enhanced metastasis, increased genomic instability, and resistance to radiation-, chemo-, or immuno-therapies. However, cells in the two-dimensional monolayer cultures typically used for cancer drug discovery experience 20%-21% O2 levels (normoxic) which are 4-fold higher than O2 levels in normal tissues and ≥10-fold higher than in the hypoxic regions of solid tumors. The oxygen electrodes, exogenous bio-reductive markers, and increased expression of endogenous hypoxia-regulated proteins like HIF-1α generally used to mark hypoxic regions in solid tumors are impractical in large sample numbers and longitudinal studies. We used a novel homogeneous live-cell permeant HypoxiTRAK™ (HPTK) molecular probe compatible with high content imaging detection, analysis, and throughput to identify and quantify hypoxia levels in live HNC multicellular tumor spheroid (MCTS) cultures over time. Accumulation of fluorescence HPTK metabolite in live normoxic HNC MCTS cultures correlated with hypoxia detection by both pimonidazole and HIF-1α staining. In HNC MCTSs, hypoxic cytotoxicity ratios for the hypoxia activated prodrugs (HAP) evofosfamide and tirapazamine were much smaller than have been reported for uniformly hypoxic 2D monolayers in gas chambers, and many viable cells remained after HAP exposure. Cells in solid tumors and MCTSs experience three distinct O2 microenvironments dictated by their distances from blood vessels or MCTS surfaces, respectively; oxic, hypoxic, or intermediate levels of hypoxia. These studies support the application of more physiologically relevant in vitro 3D models that recapitulate the heterogeneous microenvironments of solid tumors for preclinical cancer drug discovery.

Feasibility of conservative fluid administration and deresuscitation compared with usual care in critical illness: the Role of Active Deresuscitation After Resuscitation-2 (RADAR-2) randomised clinical trial.

PURPOSE: Fluid overload is common in critical illness and is associated with mortality. This study investigated the feasibility of a randomised trial comparing conservative fluid administration and deresuscitation (active removal of accumulated fluid using diuretics or ultrafiltration) with usual care in critical illness. METHODS: Open-label, parallel-group, allocation-concealed randomised clinical feasibility trial. Mechanically ventilated adult patients expected to require critical care beyond the next calendar day were enrolled between 24 and 48 h following admission to the intensive care unit (ICU). Patients were randomised to either a 2-stage fluid strategy comprising conservative fluid administration and, if fluid overload was present, active deresuscitation, or usual care. The primary endpoint was fluid balance in the 24 h up to the start of study day 3. Secondary endpoints included cumulative fluid balance, mortality, and duration of mechanical ventilation. RESULTS: One hundred and eighty patients were randomised. After withdrawal of 1 patient, 89 patients assigned to the intervention were compared with 90 patients assigned to the usual care group. The mean plus standard deviation (SD) 24-h fluid balance up to study day 3 was lower in the intervention group (- 840 ± 1746 mL) than the usual care group (+ 130 ± 1401 mL; P < 0.01). Cumulative fluid balance was lower in the intervention group at days 3 and 5. Overall, clinical outcomes did not differ significantly between the two groups, although the point estimate for 30-day mortality favoured the usual care group [intervention arm: 19 of 90 (21.6%) versus usual care: 14 of 89 (15.6%), P = 0.32]. Baseline imbalances between groups and lack of statistical power limit interpretation of clinical outcomes. CONCLUSIONS: A strategy of conservative fluid administration and active deresuscitation is feasible, reduces fluid balance compared with usual care, and may cause benefit or harm. In view of wide variations in contemporary clinical practice, large, adequately powered trials investigating the clinical effectiveness of conservative fluid strategies in critically ill patients are warranted.

Ultrasound probe scratches the pleural surface: revealing the shades of COVID-19 (SARS-CoV-2) pneumonia.

We present a case of a patient diagnosed with COVID-19 pneumonia and illustrate the changes observed using thoracic ultrasound alongside disease evolution. The case renders how COVID-19 pneumonia can sonographically correlate with chest radiograph findings and links with the oxygen requirement during different clinical stages of illness. We compare these images as the patient escalates through mild disease on low flow oxygen therapy, moderate disease on high flow oxygen therapy and severe disease requiring mechanical ventilation in the Intensive Care Unit. We then reveal further imaging showing recovery of the disease process. We recommend utilising thoracic ultrasound as it provides clinical effectiveness, ensures patient, staff and equipment safety (in the much-needed personal protective equipment environment) without exposure to radiation. This case report invites clinicians and researchers to share their thoracic ultrasound experience during the COVID-19 pandemic with a wider audience. We hope our observations will increase awareness and give credibility to thoracic ultrasound in future aspects of disease management.

Evidence for reduced immune gene diversity and activity during the evolution of termites.

The evolution of biological complexity is associated with the emergence of bespoke immune systems that maintain and protect organism integrity. Unlike the well-studied immune systems of cells and individuals, little is known about the origins of immunity during the transition to eusociality, a major evolutionary transition comparable to the evolution of multicellular organisms from single-celled ancestors. We aimed to tackle this by characterizing the immune gene repertoire of 18 cockroach and termite species, spanning the spectrum of solitary, subsocial and eusocial lifestyles. We find that key transitions in termite sociality are correlated with immune gene family contractions. In cross-species comparisons of immune gene expression, we find evidence for a caste-specific social defence system in termites, which appears to operate at the expense of individual immune protection. Our study indicates that a major transition in organismal complexity may have entailed a fundamental reshaping of the immune system optimized for group over individual defence.

Unbiased High-Throughput Drug Combination Pilot Screening Identifies Synergistic Drug Combinations Effective against Patient-Derived and Drug-Resistant Melanoma Cell Lines.

We describe the development, optimization, and validation of 384-well growth inhibition assays for six patient-derived melanoma cell lines (PDMCLs), three wild type (WT) for BRAF and three with V600E-BRAF mutations. We conducted a pilot drug combination (DC) high-throughput screening (HTS) of 45 pairwise 4×4 DC matrices prepared from 10 drugs in the PDMCL assays: two B-Raf inhibitors (BRAFi), a MEK inhibitor (MEKi), and a methylation agent approved for melanoma; cytotoxic topoisomerase II and DNA methyltransferase chemotherapies; and drugs targeting the base excision DNA repair enzyme APE1 (apurinic/apyrimidinic endonuclease-1/redox effector factor-1), SRC family tyrosine kinases, the heat shock protein 90 (HSP90) molecular chaperone, and histone deacetylases.Pairwise DCs between dasatinib and three drugs approved for melanoma therapy-dabrafenib, vemurafenib, or trametinib-were flagged as synergistic in PDMCLs. Exposure to fixed DC ratios of the SRC inhibitor dasatinib with the BRAFis or MEKis interacted synergistically to increase PDMCL sensitivity to growth inhibition and enhance cytotoxicity independently of PDMCL BRAF status. These DCs synergistically inhibited the growth of mouse melanoma cell lines that either were dabrafenib-sensitive or had acquired resistance to dabrafenib with cross resistance to vemurafenib, trametinib, and dasatinib. Dasatinib DCs with dabrafenib, vemurafenib, or trametinib activated apoptosis and increased cell death in melanoma cells independently of their BRAF status or their drug resistance phenotypes. These preclinical in vitro studies provide a data-driven rationale for the further investigation of DCs between dasatinib and BRAFis or MEKis as candidates for melanoma combination therapies with the potential to improve outcomes and/or prevent or delay the emergence of disease resistance.

Nephroureterectomy of Right-to-Left Crossed Fused Renal Ectopia with Urothelial Carcinoma.

Urothelial carcinoma in a crossed fused renal ectopia (CFRE) is an exceedingly rare clinical finding. We describe the surgical management used to treat upper tract urothelial carcinoma in a 64-year-old man with a right-to-left CFRE. Nephroureterectomy with bladder cuff excision was the treatment of choice. The fused kidney was carefully dissected until an area of demarcation emerged between the vasculature supplying the left and right moieties. Pressure was applied to the isthmus separating the two moieties, and a sharp incision was made to release the left moiety. The operation was completed with limited blood loss. Pathology revealed a high-grade T3 papillary urothelial carcinoma with negative margins. To our knowledge, the case is the first to report urothelial carcinoma in a right-to-left CFRE.

Three dimensional engineered models to study hypoxia biology in breast cancer.

Breast cancer is the second leading cause of mortality among women worldwide. Despite the available therapeutic regimes, variable treatment response is reported among different breast cancer subtypes. Recently, the effects of the tumor microenvironment on tumor progression as well as treatment responses have been widely recognized. Hypoxia and hypoxia inducible factors in the tumor microenvironment have long been known as major players in tumor progression and survival. However, the majority of our understanding of hypoxia biology has been derived from two dimensional (2D) models. Although many hypoxia-targeted therapies have elicited promising results in vitro and in vivo, these results have not been successfully translated into clinical trials. These limitations of 2D models underscore the need to develop and integrate three dimensional (3D) models that recapitulate the complex tumor-stroma interactions in vivo. This review summarizes role of hypoxia in various hallmarks of cancer progression. We then compare traditional 2D experimental systems with novel 3D tissue-engineered models giving accounts of different bioengineering platforms available to develop 3D models and how these 3D models are being exploited to understand the role of hypoxia in breast cancer progression.

Patient-derived tumor organoid predicts drugs response in glioblastoma: A step forward in personalized cancer therapy?

Despite significant medical advances, glioblastoma multiforme (GBM) remains a formidable therapeutic challenge. Advent of targeted capture sequencing and patients-derived organoid cultures may hold the key to scientifically sound individualized treatment approaches. We report on our initial experience of using the combination of these two technologies to create a tailored approach of systemic therapies for a patient with GBM, which challenges the conventional treatment paradigm, as well as specifically highlighting the complexities of such an approach and the potential for a more favorable treatment outcome.

Maximizing the Value of Cancer Drug Screening in Multicellular Tumor Spheroid Cultures: A Case Study in Five Head and Neck Squamous Cell Carcinoma Cell Lines.

With approval rates <5% and the probability of success in oncology clinical trials of 3.4%, more physiologically relevant in vitro three-dimensional models are being deployed during lead generation to select better drug candidates for solid tumors. Multicellular tumor spheroids (MCTSs) resemble avascular tumor nodules, micrometastases, or the intervascular regions of large solid tumors with respect to morphology, cell-cell and cell-extracellular matrix contacts, and volume growth kinetics. MCTSs develop gradients of nutrient and oxygen concentration resulting in diverse microenvironments with differential proliferation and drug distribution zones. We produced head and neck squamous cell carcinoma (HNSCC) MCTSs in 384-well U-bottom ultra-low-attachment microtiter plates and used metabolic viability and imaging methods to measure morphologies, growth phenotypes and the effects of 19 anticancer drugs. We showed that cell viability measurements underestimated the impact of drug exposure in HNSCC MCTS cultures, but that incorporating morphology and dead-cell staining analyses increased the number of drugs judged to have substantially impacted MCTS cultures. A cumulative multiparameter drug impact score enabled us to stratify MCTS drug responses into high-, intermediate-, and low-impact tiers, and maximized the value of these more physiologically relevant tumor cultures. It is conceivable that the viable cells present in MCTS cultures after drug exposure arise from drug-resistant populations that could represent a source of drug failure and recurrence. Long-term monitoring of treated MCTS cultures could provide a strategy to determine whether these drug-resistant populations represent circumstances where tumor growth is delayed and may ultimately give rise to regrowth.