Tumor Proliferation Rate Research Articles

Effect of 5β-dihydrotestosterone on vasodilator function and on cell proliferation.

Aging is one of the main factors associated with cardiovascular diseases. Androgens exert beneficial effects on the cardiovascular system and testosterone (TES) replacement therapy improves cardiometabolic risk factors. However, TES is contraindicated in patients with prostate cancer due to its proliferative effects on prostatic tumor cells. Additionally, TES and its reduced metabolites 5α- and 5β-dihydrotestosterone (5α-DHT and 5β-DHT) exert vasodilatory effects. Since androgen levels decrease during aging and 5β-DHT lacks genomic effects, this study is focused on analyzing its effect on vasodilator function and the proliferation rate of prostatic tumor and vascular smooth muscle cells. To study the vascular function, mesenteric arteries from aged-orchidectomized Sprague-Dawley rats were used. Mesenteric segments were divided into one control (without treatment) and three groups with the androgens (10 nM, 30 min) to analyze: acetylcholine- and sodium nitroprusside-induced responses and nitric oxide and superoxide anion production. To analyze cell proliferation, the effect of androgens on cell viability was determined. The results showed that 5β-DHT improves vasodilator function in arteries from aged-orchidectomized rats and induces antioxidant action, while the proliferation rate of the androgen-dependent prostatic tumor cells remains unaltered. These results make 5β-DHT a promising therapeutic agent for the treatment of cardiovascular pathologies.

Optimal treatment strategy for low-grade spinal cord astrocytoma: a retrospective, multicenter analysis by the Neurospinal Society of Japan

OBJECTIVE Primary spinal cord gliomas are rare, and among these astrocytomas (WHO grade II) are much rarer. The optimal treatment strategy thus remains unclear. The authors conducted a multicenter study led by the Neurospinal Society of Japan (NSJ) to analyze treatment policies and outcomes. The aim was to present optimal treatment methods for spinal cord astrocytoma and to identify predictors of better outcomes. METHODS Among 1033 consecutive cases of spinal cord intramedullary tumors treated surgically at 58 centers affiliated with the NSJ, 57 patients were diagnosed with diffuse astrocytoma (WHO grade II) and were enrolled in the present study. Among these 57 patients, treatment methods, outcomes, and tumor proliferation rate as evaluated by the MIB-1 staining index (SI) were analyzed, and the optimal treatment method for spinal cord astrocytomas (grade II) was determined. In addition, the authors searched for factors predicting better treatment outcomes. RESULTS Treatment for spinal cord astrocytoma comprised three methods: surgery alone in 30 patients, adjuvant radiation therapy in 13 patients, and adjuvant chemoradiotherapy in 13 patients. One patient who did not undergo surgery was excluded from survival analysis. Treatment with surgery alone or surgery with radiotherapy was associated with significantly longer overall and progression-free survivals than that with adjuvant chemoradiotherapy. Patients treated with radiation therapy had a higher MIB-1 SI than those treated with surgery alone. The extent of tumor resection tended to correlate with longer survival. In contrast, postoperative neurological worsening showed the inverse order. Adjuvant chemoradiotherapy was associated with the shortest survival in both total cases and recurrent cases. The optimal cutoff value of MIB-1 SI for predicting longer survival by surgery alone was less than 4.0%. CONCLUSIONS The optimal treatment for spinal cord astrocytoma is maximal tumor resection without neurological impairment. When some tumor remains in patients with an MIB-1 SI less than 4.0%, a wait-and-see approach is optimal. If the MIB-1 SI is higher than 4.0%, local radiation therapy is recommended. Adjuvant chemotherapy is not recommended for the treatment of grade II spinal cord astrocytoma.

Abstract CT233: Serum thymidine kinase 1 levels as a predictive marker for castration resistance in metastatic prostate cancer

Abstract Introduction Thymidine kinase 1 (TK1) is an enzyme associated with the cell division cycle; its levels increase during the S-phase of the cell cycle and decrease during the M-phase. In cancer TK1 release is increased both by increased cell proliferation and cell death. Thus, serum concentration of TK1 reflects the tumor volume, proliferation rate, and extent of cell death. Serum Thymidine Kinase 1 (sTK1) enzyme has been used as a prognostic, predictive, and monitoring biomarker in leukemia, Hodgkin's and non-Hodgkin's lymphomas. Additionally, sTK1 enzyme levels have been elevated in breast cancer and prostate cancer. This study evaluated whether sTK1 predicts the risk of castration resistance in patients with metastatic prostate cancer undergoing androgen deprivation therapy (ADT). Materials and Methods sTK1 levels was measured in men diagnosed with metastatic prostate cancer at 3 time points; before the initiation of ADT, 6 months after the start of treatment, and within 6 months before the development of castration resistance. Samples at study visits of ESTO2 trial, which compares atorvastatin to placebo in combination with ADT. The trial intervention was blinded at analysis. Cox regression modeling was used to assess whether sTK1 values predict the risk of castration resistance. sTK1 was analyzed both as continuous and categorical variable, stratified by median value 0.12 ng/ml. The time from the initiation of ADT to the formation of castration resistance, death, or a general index date (May 31, 2023) was used as the time-metric. Results The study included serum samples from 70 patients, of which 23 had developed castration resistance by May 31,2023. The median follow-up time was 13 months. The sTK1 value measured before ADT initiation did not predict the risk of castration resistance (HR 0.91, 95% CI 0.62-1.35). However, sTK1 at 6 months after the initiation of ADT or up to a maximum of 6 months before formation of castration resistance did predict the risk (HR 1.5, 95% CI 1.07-2.1 and HR 1.79, 95% CI 1.16-2.76, respectively). sTK1 predicted the risk at both measurement points also when analyzed as categorical variable. sTK1 was predictive only among men with metastatic disease; sTK1 no longer predicted the risk of castration resistance who started ADT for biochemically recurrent, non-metastatic disease. Conclusions Our findings suggest that sTK1 value can be used to predict the risk of progression to castration resistance during ADT in metastatic prostate cancer. However, these findings need validation from larger datasets. Citation Format: Aino Siltari, Paavo Raittinen, Jarno Riikonen, Juha Koskimäki, Tomi Pakarainen, Mikael Anttinen, Otto Ettala, Teuvo Tammela, Stig Linder, Teemu J. Murtola. Serum thymidine kinase 1 levels as a predictive marker for castration resistance in metastatic prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT233.

Abstract 6428: Transcriptome analysis of tissues and peripheral blood revealed potential biomarkers for chemo/radio-immunotherapy in non-small cell lung cancer

Abstract Background: Combination of anti-PD-(L)1 antibody with chemotherapy has shown promising efficacy in advanced/metastatic non-small cell lung cancer (NSCLC). Dynamics of peripheral blood mononuclear cells (PBMC) might have impact on repertore of immune cells further resulting different immune infiltration in tumor microenvironment. Thus, monitoring changes in PBMC during therapy or measuring tumor microenvironment provides the possibility to predict the efficacy of tumor immunotherapy. Methods: Patients diagnosed with NSCLC (Stage III-IV)were enrolled in this study. Anti-PD-L1 and chemo/radio combination therapy was performed as adjuvant therapy. Tumor samples were obtained prior to adjuvant therapy PBMC samples were obtaind at multiple time points, including prior adjuvant therapy, 3 months after adjuvant therapy, and 3 months after adjuvant therapy. Tumor and PBMC mRNA sequencing were performed by Amoy Diagnostics Co Ltd. (Xiamen, China). Patients who achieved CR/PR/SD and PFS > 6 months were defined as well responders. Pathway enrichment and GSEA analyses were performed by clusterProfiler (version 4.0.5) on GO, KEGG, and from six different gene sets. Correlations between immune cellular signature ES scores and gene expression were estimated using Pearson correlation. Results: 28 patients were enrolled; mean age was 60.38±7.86 years, 27 (96.4%) patients were male. 21 (75.0%) patients were identified as responder and 7 (25.0%) were non-responder. In the baseline tumor samples, immune infiltration was more extensive in responders compared to non-responders. Cytotoxic lymphocytes, activated CD8+ T cell, and NK cells were significantly enriched in responders. High expression of CCL17 and down regulation of CTSG/PLK1/PRTN3, a signaling axis that inhibits histone H3 hydrolysis and promotes monocyte to macrophage differentiation, was significant in responders. Dynamic monitoring of PBMC before and after treatment showed significant upregulation of immune infiltration-related pathways in responders, including effector cells, NK cells and CD8+ T cells. In the non-responder group, the up-regulated pathways after treatment were mainly enriched in tumor growth rate, EMT, and matrix remodeling. Multi-time point analysis showed that CEACAM5/MKI67 level and tumor proliferation rate in non-responders were higher than those in responders at each time point after treatment. Conclusion: Baseline tumor transcripton signatures and dynamic changes in PBMC could be applied to develop novel biomarkers for immune-related therapy. Patients with stronger immune infiltration signals in baseline tumor samples and PBMC after treatment had better immune response. The upregulation of proliferation-related signals in PBMC predicts poor immune response. Citation Format: Jing Hu, Jianguo Zhang, Peng Cheng, Yanhua Chen, Changbin Zhu, Feilin Yi, Conghua Xie. Transcriptome analysis of tissues and peripheral blood revealed potential biomarkers for chemo/radio-immunotherapy in non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6428.

An oncogene regulating chromatin favors response to immunotherapy

ABSTRACT Many biological processes related to cell function and fate begin with chromatin alterations, and many factors associated with the efficacy of immune checkpoint inhibitors (ICIs) are actually downstream events of chromatin alterations, such as genome changes, neoantigen production, and immune checkpoint expression. However, the influence of genes as chromatin regulators on the efficacy of ICIs remains elusive, especially in gastric cancer (GC). In this study, thirty out of 1593 genes regulating chromatin associated with a favorable prognosis were selected for GC. CHAF1A, a well-defined oncogene, was identified as the highest linkage hub gene. High CHAF1A expression were associated with microsatellite instability (MSI), high tumor mutation burden (TMB), high tumor neoantigen burden (TNB), high expressions of PD-L1 and immune effector genes, and live infiltration of immune cells. High CHAF1A expression indicated a favorable response and prognosis in immunotherapy of several cohorts, which was independent of MSI, TMB, TNB, PD-L1 expression, immune phenotype and transcriptome scoring, and improved patient selection based on these classic biomarkers. In vivo, CHAF1A knockdown alone inhibited tumor growth but it impaired the effect of an anti-PD-1 antibody by increasing the relative tumor proliferation rate and decreasing the survival benefit, potentially through the activation of TGF-β signaling. In conclusion, CHAF1A may be a novel biomarker for improving patient selection in immunotherapy.

Exploring the molecular and immune landscape of cellular senescence in lung adenocarcinoma.

The connection between aging and cancer is complex. Previous research has highlighted the association between the aging process of lung adenocarcinoma (LUAD) cells and the immune response, yet there remains a gap in confirming this through single-cell data validation. Here, we aim to develop a novel aging-related prognostic model for LUAD, and verify the alterations in the genome and immune microenvironment linked to cellular senescence. We integrated a comprehensive collection of senescence genes from the GenAge and CellAge databases and employed the least absolute shrinkage and selection operator (LASSO) Cox analysis to construct and validate a novel prognostic model for LUAD. This model was then utilized to examine the relationship between aging, tumor somatic mutations, and immune cell infiltration. Additionally, we explored the heterogeneity of senescence and intercellular communication within the LUAD tumor microenvironment (TME) through single-cell transcriptomic data analysis. By exploring the expression profiles of 586 cellular senescence-related genes in 428 LUAD patients, we constructed an aging-related genes (ARGs) risk model included 10 ARGs and validated it as an independent prognostic predictor for LUAD patients. Notably, patients with low aging scores (LAS group) exhibited better survival, lower tumor mutation burden (TMB), lower somatic mutation frequency, lower tumor proliferation rate, and an immune activated phenotype compared to patients with high aging scores (HAS group). While the HAS group was enriched in tumor cells and showed a lower infiltration of CD8-CCR7, CD8- CXCL13, CD8-GNLY, FCGR3A NK cells, XCL1 NK cells, plasma cell (PC) and other immune subsets. Furthermore, the SPP1 and TENASCIN pathways, associated with tumor immune escape and tumor progression, were also enriched in the HAS group. Additionally, our study also indicated that senescence levels were heterogeneous in the LUAD tumor microenvironment (TME), especially with tumor cells in the LAS group showing higher age scores compared to those in the HAS group. Collectively, our findings underscore that ARRS through ARGs serves as a robust biomarker for the prognosis in LUAD.

Individualized chemotherapy and efficacy analysis of hepatoblastoma in children.

We aimed to assess the clinical utility of the mini patient-derived xenograft (MiniPDX) model in screening individualized chemotherapy regimens for pediatric hepatoblastoma. We included 31 children with hepatoblastoma who had unsatisfactory decreases in alpha-fetoprotein levels during neoadjuvant chemotherapy or poor clinical control of recurrence with or without metastasis. We established a MiniPDX model using surgically resected tumor tissue specimens. The sensitivities of five chemotherapeutic regimens were tested to determine the one with the lowest tumor proliferation rate, which was then set as the experimental group. We compared the clinical characteristics and efficacy with those of conventional chemotherapy regimens. The median follow-up period for the experimental group was 27months, with a complete remission (CR) rate of 80.64%. Among stage IV cases, there was a significant between-group difference in CR rate (experimental [73.68%] vs. control [37.5%]) and 3-year event-free survival rate (79.3% vs. 26.7%). The most effective individualized chemotherapy regimens were ifosfamide + pirarubicin + etoposide + carboplatin (54.84%), followed by pirubicin + cyclophosphamide + cisplatin (16.13%), ifosfamide + carboplatin + etoposide (12.90%), cisplatin + 5-fluorouracil + vincristine + adriamycin (12.90%), and vincristine + irinotecan + cyclophosphamide + cisplatin (3.23%). Using the MiniPDX model to screen individualized chemotherapy regimens for pediatric hepatoblastoma can significantly improve the CR rate.

High pyroptosis activity in pancreatic adenocarcinoma: poor prognosis and oxaliplatin resistance.

Pyroptosis, as a type of inflammatory programmed cell death, has been studied in inflammatory diseases and numerous cancers but its role in pancreatic ductal adenocarcinoma (PDAC) remains further exploration. A TCGA-PDAC cohort was enrolled for bioinformatics analysis to investigate the effect of pyroptosis on the prognosis and drug sensitivity of patients. PA-TU-8988T and CFPAC-1 cells were selected for investigating the role of GSDMC in PDAC. A distinct classification pattern of PDAC mediated by 21 pyroptosis-related genes (PRGs) was identified. It was suggested that higher pyroptosis activity was associated with poor prognosis of patients and higher tumor proliferation rates. We further established a prognostic model based on three PRGs (GSDMC, CASP4 and NLRP1) and the TCGA-PDAC cohort was classified into low and high-risk subgroups. It is noteworthy that the high-risk group showed significantly higher tumor proliferation rates and was proved to be highly correlated with oxaliplatin resistance. Further experiments suggested that overexpression of GSDMC promoted the proliferation and oxaliplatin resistance of PA-TU-8988T cells in vitro and vivo, while downregulation of GSDMC showed opposite effects in CFPAC-1 cells. Finally, we found that the activation of pentose phosphate pathway (PPP) was the mechanism by which GSDMC overexpression promoted the proliferation and oxaliplatin resistance of pancreatic cancer cells. In this study, we found that higher pyroptosis activity is associated with worse prognosis and oxaliplatin resistance of PDAC patients. In addition, as a core effector of pyroptosis, GSDMC promoted proliferation and oxaliplatin resistance of pancreatic cancer cells, which will provide new therapeutic target for PDAC patients.

Frequent upregulation of HER2 protein in hormone-receptor-positive HER2-negative breast cancer after short-term neoadjuvant endocrine therapy.

Endocrine resistant metastatic disease develops in ~ 20-25% of hormone-receptor-positive (HR+) breast cancer (BC) patients despite endocrine therapy (ET) use. Upregulation of HER family receptor tyrosine kinases (RTKs) represent escape mechanisms in response to ET in some HR+ tumors. Short-term neoadjuvant ET (NET) offers the opportunity to identify early endocrine escape mechanisms initiated in individual tumors. This was a single arm, interventional phase II clinical trial evaluating 4weeks (± 1week) of NET in patients with early-stage HR+/HER2-negative (HER2-) BC. The primary objective was to assess NET-induced changes in HER1-4 proteins by immunohistochemistry (IHC) score. Protein upregulation was defined as an increase of ≥ 1 in IHC score following NET. Thirty-seven patients with cT1-T3, cN0, HR+/HER2- BC were enrolled. In 35 patients with evaluable tumor HER protein after NET, HER2 was upregulated in 48.6% (17/35; p = 0.025), with HER2-positive status (IHC 3+ or FISH-amplified) detected in three patients at surgery, who were recommended adjuvant trastuzumab-based therapy. Downregulation of HER3 and/or HER4 protein was detected in 54.2% of tumors, whereas HER1 protein remained low and unchanged in all cases. While no significant volumetric reduction was detected radiographically after short-term NET, significant reduction in tumor proliferation rates were observed. No significant associations were identified between any clinicopathologic covariates and changes in HER1-4 protein expression on multivariable analysis. Short-term NET frequently and preferentially upregulates HER2 over other HER family RTKs in early-stage HR+/HER2- BC and may be a promising strategy to identify tumors that utilize HER2 as an early endocrine escape pathway. Trial registration number: NCT03219476.

Procoagulant genes may affect angiogenesis, epithelial-mesenchymal transition, survival prognosis and tumor immune microenvironment in patients with urothelial carcinoma.

Factors related to coagulation regulation are closely related to angiogenesis, epithelial-mesenchymal transition, tumor proliferation and metastasis, and tumor immune microenvironment remodeling in tumors. To date, there are no quantitative indicators of coagulation associated with urothelial cancer. We classified urothelial cancer into high coagulation and low coagulation subtypes by screening for procoagulant-related molecular features and screened out relevant genes representing the coagulation state of urothelial carcinoma. Tumors with increased procoagulant gene expression were consistently associated with higher T-staging (p < 0.001), lymph node metastasis (p < 0.001), stage (p < 0.001), and grade (p = 0.046). Furthermore, high expression of procoagulant genes predicts a worse prognosis, a higher tumor proliferation rate and increased angiogenesis within the tumor. In addition, according to cibersort algorithm, the increased expression of procoagulant gene was negatively correlated with the degree of T-lymphocyte infiltration and positively correlated with the degree of M2 macrophage infiltration. Increased expression of procoagulant genes in data sets treated with immune checkpoints also predicted worse response and worse prognosis. At the same time, the expression of procoagulant genes in bladder cancer promoted the activation of coagulation, EMT, TGF-β and WNT pathways.

Breast cancer in young women: a rising threat: A 5-year follow-up comparative study.

Breast cancer in young women is usually considered as breast cancer occurring in women younger than 40 years and is the most frequent cancer-related cause of death in these patients. In the past few years, there seems to be an increasing trend in the prevalence of breast cancer in young women, which, associated with poorer prognosis, more aggressive histologic features, and more frequent recurrence rates, makes it a rising threat to young women. This study aimed to evaluate the biological behavior of breast cancer in young women in our institution. A retrospective, unicentric, cohort study was conducted between 2012 and 2016. All consecutive patients with breast cancer were enrolled in the study. Cases were divided into two groups: case group, those younger than 40 years, and control group, those 40 years or older. The exclusion criterion was nonoperative treatment. Several clinical and pathologic parameters were evaluated, as well as were overall survival time and disease-free survival time. The incidence of breast cancer in young women presented a rising tendency over the study period. Significant differences were observed in the comparison of the groups according to body mass index, age at menarche, age at birth of the first child, and proliferation rate. There were no differences in overall survival and disease-free survival rates between the groups. Young women had a more symptomatic presentation, a greater tumor proliferation rate, but similar outcomes compared with older patients. Greater multicentric studies are needed to confirm or refute these results.

MicroRNA-155-5p Targets JADE-1, Promoting Proliferation, Migration, and Invasion in Clear Cell Renal Cell Carcinoma Cells.

Clear cell renal cell carcinoma (ccRCC) incidence has been rising in recent years, with strong association between differential microRNA (miRNA) expression and neoplastic progression. Specifically, overexpression of miR-155-5p has been associated with promoting aggressive cancer in ccRCC and other cancers. In this study, we further investigate the role of this miRNA and one of its protein targets, Jade-1, to better understand the mechanism behind aggressive forms of ccRCC. Jade-1, a tumor suppressor, is stabilized by Von-Hippel Lindau (VHL), which is frequently mutated in ccRCC. Experiments featuring downregulation of miR-155-5p in two ccRCC cell lines (786-O and Caki-1) attenuated their oncogenic potential and led to increased levels of Jade-1. Conversely, knockdown experiments with an anti-Jade-1 shRNA in 786-O and Caki-1 cells showed increased metastatic potential through elevated proliferation, migration, and invasion rates. In a mouse xenograft model, downregulation of miR-155 decreased the rate of tumor implantation and proliferation. Direct interaction between miR-155-5p and Jade-1 was confirmed through a 3'UTR luciferase reporter assay. These findings further elucidate the mechanism of action of miR-155-5p in driving an aggressive phenotype in ccRCC through its role in regulating Jade-1.

Apparent diffusion coefficient values effectively predict cell proliferation and determine oligodendroglioma grade

This study aims to evaluate the value of conventional magnetic resonance imaging (MRI) features and apparent diffusion coefficient (ADC) values in differentiating oligodendroglioma of various grades and explore the correlation between ADC and Ki-67. The preoperative MRI data of 99 patients with World Health Organization (WHO) grades 2 (n = 42) and 3 (n = 57) oligodendroglioma confirmed by surgery and pathology were retrospectively analyzed. Conventional MRI features, ADCmean, ADCmin, and normalized ADC (nADC) were compared between the two groups. A receiver operating characteristic curve was used to evaluate each parameter's diagnostic efficacy in differentiating the two tumor types. Each tumor's Ki-67 proliferation index was also measured to explore its relationship with the ADC value. Compared with WHO2 grade tumors, WHO3 grade tumors had a larger maximum diameter and more significant cystic degeneration/necrosis, edema, and moderate/severe enhancement (all P < 0.05). The ADCmin, ADCmean, and nADC values of the WHO3 and WHO2 grade tumors were significantly different, and the ADCmin value most accurately distinguished the two tumor types, yielding an area under the curve value of 0.980. When 0.96 × 10-3 mm2/s was used as the differential diagnosis threshold, the sensitivity, specificity, and accuracy of the two groups were 100%, 93.00%, and 96.96%, respectively. The ADCmin (r = -0.596), ADCmean (r = - 0.590), nADC (r = - 0.577), and Ki-67 proliferation index values had significantly negative correlations (all P < 0.05). Conventional MRI features and ADC values are beneficial in the noninvasive prediction of the WHO grade and tumor proliferation rate of oligodendroglioma.

Abstract 971: Thymidine Kinase activity - A liquid biomarker reflecting proliferation rate and treatment efficacy in solid tumors provides unique guidance in oncology trials and drug development

Abstract Thymidine Kinase (TK) plays a fundamental role in DNA synthesis and cell proliferation. Expression of the enzyme is highly cell cycle dependent and correlates with cell growth state. TK activity (TKa) is present in all proliferating cells but release into blood circulation is low or absent from quiescent cells. Numerous studies have shown TKa to be elevated in solid tumors as well as in the blood of cancer patients with active disease. DiviTum® TKa, a clinically and analytically validated FDA cleared assay, can measure and quantify TKa in serum or plasma isolated from human and animal blood samples. TKa as a biomarker offers valuable information at all stages of drug development; from drug efficacy and dose response studies in cell culture and tumor xenograft models, to patient selection and treatment monitoring in clinical trials. Using TKa to measure the impact on cell proliferation as a drug evaluation endpoint can confirm mechanism of action efficacy and the minimally effective dose of a new compound rather than a maximally tolerated dose. In both cultured cells and mouse xenografts, a complete shutdown of tumor cell proliferation (assessed by TKa) can be observed well before and at much lower doses than when cell death or toxicity is used as the dose determination endpoint. The TKa-biomarker can also be used as a pharmacodynamic tool in clinical trials to improve study endpoints. Patient baseline levels (BL) of TKa are predictive/prognostic and can be used to identify which patients will respond to the therapy being tested vs those who will not. In metastatic breast cancer, a BL TKa value of &amp;lt;250 DuA is significantly correlated with longer PFS (HR=1.76, p&amp;lt;0.0001) and OS (HR=2.38, p&amp;lt;0.0001) independent of patient and disease characteristics. On-therapy TKa levels and dynamics can be used in clinical trials to evaluate response to a drug as early as two weeks into the first cycle. In patients receiving CDK4/6 inhibitors, TKa levels &amp;gt;140 DuA at cycle 1 day 15 predicts for lack of benefit to the drug (HR=5.65, p&amp;lt;0.0001). TKa can also be used as a predictive biomarker for drugs that cause an immune reaction and increase in cell proliferation such as immune checkpoint inhibitors (ICIs). When effective, ICIs cause an increase in immune cell proliferation which can be detected by elevated levels of TKa. Patients who do not achieve &amp;gt;1.5 fold change in TKa levels as compared to BL, have a significantly shorter duration of response to an ICI (HR=3.70, p=0.002) and patients with high TKa during ICI treatment have significantly longer OS (HR=3.49, p&amp;lt;0.05). In summary, TKa is a translational liquid biomarker that can bridge between preclinical and clinical studies, providing fundamental information for decision making during early and late stage drug development. Data and examples of the utility of TKa as a companion diagnostic for drug development will be presented. Citation Format: Mattias K. Bergqvist, Hanna Ritzén, Amy Williams. Thymidine Kinase activity - A liquid biomarker reflecting proliferation rate and treatment efficacy in solid tumors provides unique guidance in oncology trials and drug development [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 971.

Abstract 4277: Measuring proliferation rates of distinct tumour clones using single-cell DNA sequencing

Abstract Background: Tumour proliferation rate is a key phenotypic feature of cancer, with higher rates linked to poorer clinical outcomes. Thus far, proliferation rates have been measured using pathological or experimental techniques on bulk tumour samples. However, while tumours are heterogeneous compositions of distinct clones with varying levels of fitness, measuring the proliferation of individual clones has not been possible to date. We hypothesise that enabling the identification of the most proliferative clones would reveal genomic hallmarks of aggressive clones, or the prediction of their potential phenotype, e.g., metastatic potential. Methods: We have developed SPRINTER (Single-cell Proliferation Rate Inference in Neoplasms Through Evolutionary Routes), a novel computational method to measure proliferation rates in individual tumour clones using single-cell whole-genome DNA sequencing. To assess the accuracy and power of SPRINTER, we have also developed an experimental approach to DNA sequence &amp;gt;18,000 single cells, accurately separated in different DNA-replication phases. We have sequenced and applied SPRINTER to &amp;gt;10,000 non-small cell lung cancer cells from longitudinal and metastatic tumour samples within the TRACERx study and PEACE autopsy programme. We have further analysed published data from &amp;gt;10,000 breast cancer cells. Results: We demonstrate that SPRINTER can accurately identify subpopulations of cells with different proliferation rates using relatively small numbers of cells, in contrast to previous preliminary approaches. While our estimates are concordant with previous bulk experimental studies (5-40%), we importantly have identified clonal heterogeneity in proliferation rates. Using bulk analysis, we have identified patterns of dissemination of tumour clones in non-small cell lung cancer. Integrating this with single-cell data, our results indicate that more widely disseminating tumour clones have higher proliferation rates, suggesting a link between proliferation and dissemination potential. We additionally find that clones are more proliferative in the metastatic versus the primary setting. Furthermore, we have identified high proliferation clones that may have a selective advantage in a breast tumour, and have inferred that they likely arose recently in cancer evolution. Conclusions: We have developed a novel method that enables accurate identification of proliferation rates of individual tumour clones using single-cell DNA sequencing data, allowing the investigation of genomic hallmarks in highly proliferative clones that might lead to higher fitness. Citation Format: Olivia Lucas, Sophie Ward, Rija Zaidi, Mark Hill, Emilia Lim, Haoran Zhai, Abigail Bunkum, Sonya Hessey, Michelle Dietzen, Andrew Rowan, Cristina Naceur-Lombardelli, Nnenna Kanu, Mariam Jamal-Hanjani, Charles Swanton, Simone Zaccaria. Measuring proliferation rates of distinct tumour clones using single-cell DNA sequencing. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4277.

Systems-based digital twins to help characterize clinical dose-response and propose predictive biomarkers in a Phase I study of bispecific antibody, mosunetuzumab, in NHL.

Phase I oncology clinical trials often comprise a limited number of patients representing different disease subtypes who are divided into cohorts receiving treatment(s) at different dosing levels and schedules. Here, we leverage a previously developed quantitative systems pharmacology model of the anti-CD20/CD3 T-cell engaging bispecific antibody, mosunetuzumab, to account for different dosing regimens and patient heterogeneity in the phase I study to inform clinical dose/exposure-response relationships and to identify biological determinants of clinical response. We developed a novel workflow to generate digital twins for each patient, which together form a virtual population (VPOP) that represented variability in biological, pharmacological, and tumor-related parameters from the phase I trial. Simulations based on the VPOP predict that an increase in mosunetuzumab exposure increases the proportion of digital twins with at least a 50% reduction in tumor size by day 42. Simulations also predict a left-shift of the exposure-response in patients diagnosed with indolent compared to aggressive non-Hodgkin's lymphoma (NHL) subtype; this increased sensitivity in indolent NHL was attributed to the lower inferred values of tumor proliferation rate and baseline T-cell infiltration in the corresponding digital twins. Notably, the inferred digital twin parameters from clinical responders and nonresponders show that the potential biological difference that can influence response include tumor parameters (tumor size, proliferation rate, and baseline T-cell infiltration) and parameters defining the effect of mosunetuzumab on T-cell activation and B-cell killing. Finally, the model simulations suggest intratumor expansion of pre-existing T-cells, rather than an influx of systemically expanded T-cells, underlies the antitumor activity of mosunetuzumab.

Predicting chemosensitivity based on mini patient-derived xenografts in osteosarcoma patients: A retrospective study

The survival of patients diagnosed with osteosarcoma has not improved in the past three decades because of chemoresistance. This study aimed to improve the prognosis of patients with osteosarcoma. From January 1, 2018, to June 30, 2019, a total of 14 patients with osteosarcoma were enrolled who underwent mini patient-derived xenograft (mini-PDX) assay in our hospital. We recruited 14 patients with osteosarcoma having acquirable lesions to establish PDX models and examine the sensitivity of nine drugs, including methotrexate (MTX), ifosfamide (IFO), epirubicin, and etoposide. Drug sensitivity was evaluated using the tumor relative proliferation rate (TRPR), and the patients' responses were assessed according to the RECIST 1.1 guidelines. The difference in TRPR was analyzed using a paired t-test, while progression-free survival (PFS) was analyzed using the Kaplan-Meier method. The mini-PDX results revealed that IFO had a lower tumor proliferation rate than MTX, indicating that IFO was more sensitive in patients with osteosarcoma (38.3% vs. 84.3%, P = 0.031). Thus, the regimen where IFO alternates with doxorubicin and cisplatin was recommended as adjuvant chemotherapy. MTX could replace IFO if the TRPR was better. Finally, 11 patients received adjuvant chemotherapy. A comparison of PFS revealed that sensitive patients with TRPR of <40% had a better prognosis (9.4 months vs. 3.7 months, P = 0.0324). Chemotherapy based on mini-PDX can improve the survival of patients with osteosarcoma whose TRPR was <40%, and that chemotherapy without MTX could be an alternative for osteosarcoma.

Is CCL2 an Important Mediator of Mast Cell-Tumor Cell Interactions in Oral Squamous Cell Carcinoma?

In this study, we aimed to evaluate the influence of interactions between mast cells (MCs) and oral squamous cell carcinoma (OSCC) tumor cells on tumor proliferation and invasion rates and identify soluble factors mediating this crosstalk. To this end, MC/OSCC interactions were characterized using the human MC cell line LUVA and the human OSCC cell line PCI-13. The influence of an MC-conditioned (MCM) medium and MC/OSCC co-cultures on the proliferative and invasive properties of the tumor cells was investigated, and the most interesting soluble factors were identified by multiplex ELISA analysis. LUVA/PCI-13 co-cultures increased tumor cell proliferation significantly (p = 0.0164). MCM reduced PCI-13 cell invasion significantly (p = 0.0010). CC chemokine ligand 2 (CCL2) secretion could be detected in PCI-13 monocultures and be significantly (p = 0.0161) increased by LUVA/PCI-13 co-cultures. In summary, the MC/OSCC interaction influences tumor cell characteristics, and CCL2 could be identified as a possible mediator.

Molecular characterization based on tumor microenvironment-related signatures for guiding immunotherapy and therapeutic resistance in lung adenocarcinoma.

Background: Although the role of tumor microenvironment in lung adenocarcinoma (LUAD) has been explored in a number of studies, the value of TME-related signatures in immunotherapy has not been comprehensively characterized. Materials and Methods: Consensus clustering was conducted to characterize TME-based molecular subtypes using transcription data of LUAD samples. The biological pathways and immune microenvironment were assessed by CIBERSORT, ESTIMATE, and gene set enrichment analysis. A TME-related risk model was established through the algorithms of least absolute shrinkage and selection operator (Lasso) and stepwise Akaike information criterion (stepAIC). Results: Four TME-based molecular subtypes including C1, C2, C3, and C4 were identified, and they showed distinct overall survival, genomic characteristics, DNA methylation pattern, immune microenvironment, and biological pathways. C1 had the worst prognosis and high tumor proliferation rate. C3 and C4 had higher enrichment of anti-tumor signatures compared to C1 and C2. C4 had evidently low enrichment of epithelial-mesenchymal transition (EMT) signature and tumor proliferation rate. C3 was predicted to be more sensitive to immunotherapy compared with other subtypes. C1 is more sensitive to chemotherapy drugs, including Docetaxel, Vinorelbine and Cisplatin, while C3 is more sensitive to Paclitaxel. A five-gene risk model was constructed, which showed a favorable performance in three independent datasets. Low-risk group showed a longer overall survival, more infiltrated immune cells, and higher response to immunotherapy than high-risk group. Conclusion: This study comprehensively characterized the molecular features of LUAD patients based on TME-related signatures, demonstrating the potential of TME-based signatures in exploring the mechanisms of LUAD development. The TME-related risk model was of clinical value to predict LUAD prognosis and guide immunotherapy.

Polyphenols from Prunus mume: extraction, purification, and anticancer activity.

Prunus mume is an ancient medicinal herb and food that are commonly used in Asian countries with high nutritional ingredients and biological activities. Polyphenols are important functional components in Prunus mume. To obtain a more efficient extraction process of Prunus mume polyphenols, a single-factor test and response surface method were used. After extraction and purification, the final polyphenol content of Prunus mume (L1) was up to 90%. Biological experiments showed that L1 had high anticancer activity against HeLa (125.28 μg mL-1), HepG2 (117.24 μg mL-1), MCF-7 (170.19 μg mL-1), and A549 (121.78 μg mL-1) in vitro by MTT assay. The combination of DDP and DOX significantly enhanced the anticancer activity of the four cell lines, especially L1-DOX had the smallest IC50 value of 0.04 μg mL-1 against HepG2 cells, indicating the combination of drugs had synergistic effects. It is further demonstrated that L1 could inhibit cell proliferation by inducing apoptosis with ROS detection and confocal fluorescence images. The relative tumor proliferation rate (T/C) was 40.6%, and the tumor inhibition rate was 57.9%, indicating L1 to have no significant toxicity but high anti-HepG2 activity in vivo. Although the study is very limited, it is anticipated to provide a reference for further exploration of the functionality of the plant.