Modulating Chemosensitivity of Tumors to Platinum-Based Antitumor Drugs by Transcriptional Regulation of Copper Homeostasis.

Platinum (Pt)-based antitumor agents have been effective in treating many human malignancies. Drug importing, intracellular shuffling, and exporting-carried out by the high-affinity copper (Cu) transporter (hCtr1), Cu chaperone (Ato x1), and Cu exporters (ATP7A and ATP7B), respectively-cumulatively contribute to the chemosensitivity of Pt drugs including cisplatin and carboplatin, but not oxaliplatin. This entire system can also handle Pt drugs via interactions between Pt and the thiol-containing amino acid residues in these proteins; the interactions are strongly influenced by cellular redox regulators such as glutathione. hCtr1 expression is induced by acute Cu deprivation, and the induction is regulated by the transcription factor specific protein 1 (Sp1) which by itself is also regulated by Cu concentration variations. Copper displaces zinc (Zn) coordination at the zinc finger (ZF) domains of Sp1 and inactivates its DNA binding, whereas Cu deprivation enhances Sp1-DNA interactions and increases Sp1 expression, which in turn upregulates hCtr1. Because of the shared transport system, chemosensitivity of Pt drugs can be modulated by targeting Cu transporters. A Cu-lowering agent (trientine) in combination with a Pt drug (carboplatin) has been used in clinical studies for overcoming Pt-resistance. Future research should aim at further developing effective Pt drug retention strategies for improving the treatment efficacy.

Cost effectiveness of cancer treatment in Taiwan.

BACKGROUND/PURPOSE: This study aims to examine the cost effectiveness of treating major cancers compared with other major illnesses in Taiwan. METHODS: We collected data on 395,330 patients with cancer, 125,277 patients with end-stage renal disease, and 50,481 patients under prolonged mechanical ventilation during 1998-2007. They were followed for 10-13 years to estimate lifetime survival functions using a semiparametric method. EuroQol five-dimension was used to measure the quality of life for 6189 cancer patients and 1401 patients with other illnesses. The mean utility values and healthcare costs reimbursed by the National Health Insurance were multiplied with the corresponding survival probabilities to estimate quality-adjusted life expectancies and lifetime costs, respectively. Data of 22,344 cancer patients under hospice care (considered as a comparison group) were used to conduct a cost-effectiveness analysis. Sensitivity analysis was conducted by assuming patients without treatment survived for 2 years with a quality of life value of 0.5. RESULTS: The costs of care for patients under prolonged mechanical ventilation and those with end-stage renal disease were US$41,780-53,708 per quality-adjusted life year (QALY) and US$18,222-18,465 per QALY, respectively, which are equivalent to 2.17-2.79 gross domestic product (GDP) per capita per QALY and 1.18-1.25 GDP per capita per QALY. The costs of care for the nine different cancers were less than 1 GDP per capita per QALY, with those of lung, esophagus, and liver cancers being the highest. Sensitivity analysis showed the same conclusion. Lifetime risks of six out of nine cancer sites show an increased trend. CONCLUSION: Cancer care in Taiwan seemed cost effective compared with that of other illnesses, but prevention is necessary to make the National Health Insurance more sustainable.

Regulation of the high-affinity copper transporter (hCtr1) expression by cisplatin and heavy metals.

Platinum-based antitumor agents have been the mainstay in cancer chemotherapy for many human malignancies. Drug resistance is an important obstacle to achieving the maximal therapeutic efficacy of these drugs. Understanding how platinum drugs enter cells is of great importance in improving therapeutic efficacy. It has been demonstrated that human high-affinity copper transporter 1 (hCtr1) is involved in transporting cisplatin into cells to elicit cytotoxic effects, although other mechanisms may exist. In this communication, we demonstrate that cisplatin transcriptionally induces the expression of hCtr1 in time- and concentration-dependent manners. Cisplatin functions as a competitor for hCtr1-mediated copper transport, resulting in reduced cellular copper levels and leading to upregulated expression of Sp1, which is a positive regulator for hCtr1 expression. Thus, regulation of hCtr1 expression by cisplatin is an integral part of the copper homeostasis regulation system. We also demonstrate that Ag(I) and Zn(II), which are known to suppress hCtr1-mediated copper transport, can also induce hCtr1/Sp1 expression. In contrast, Cd(II), another inhibitor of copper transport, downregulates hCtr1 expression by suppressing Sp1 expression. Collectively, our results demonstrate diverse mechanisms of regulating copper metabolism by these heavy metals.

A computed tomography radiomics-based model for predicting osteoporosis after breast cancer treatment.

Many treatments against breast cancer decrease the level of estrogen in blood, resulting in bone loss, osteoporosis and fragility fractures in breast cancer patients. This retrospective study aimed to evaluate a novel opportunistic screening for cancer treatment-induced bone loss (CTIBL) in breast cancer patients using CT radiomics. Between 2011 and 2021, a total of 412 female breast cancer patients who received treatment and were followed up in our institution, had post-treatment dual-energy X-ray absorptiometry (DXA) examination of the lumbar vertebrae and had post-treatment chest CT scan that encompassed the L1 vertebra, were included in this study. Results indicated that the T-score of L1 vertebra had a strongly positive correlation with the average T-score of L1-L4 vertebrae derived from DXA (r = 0.91, p < 0.05). On multivariable analysis, four clinical variables (age, body weight, menopause status, aromatase inhibitor exposure duration) and three radiomic features extracted from the region of interest of L1 vertebra (original_firstorder_RootMeanSquared, wavelet.HH_glcm_InverseVariance, and wavelet.LL_glcm_MCC) were selected for building predictive models of L1 T-score and bone health. The predictive model combining clinical and radiomic features showed the greatest adjusted R2 value (0.557), sensitivity (83.6%), specificity (74.2%) and total accuracy (79.4%) compared to models that relied solely on clinical data, radiomic features, or Hounsfield units. In conclusion, the clinical-radiomic predictive model may be used as an opportunistic screening tool for early identification of breast cancer survivors at high risk of CTIBL based on non-contrast CT images of the L1 vertebra, thereby facilitating early intervention for osteoporosis.

Metformin enhances cisplatin cytotoxicity by suppressing signal transducer and activator of transcription-3 activity independently of the liver kinase B1-AMP-activated protein kinase pathway.

Metformin has been used as first-line treatment in patients with type 2 diabetes, and is reported to reduce cancer risk and progression by activating the liver kinase B1 (LKB1)-AMP-activated protein kinase (AMPK) pathway. Cisplatin remains the main drug for treating advanced non-small-cell lung cancer. However, drug resistance often develops through several mechanisms during the treatment course, including one mechanism mediated by the activation of the IL-6/signal transducer and activator of transcription (STAT)-3 pathway, related to the generation of reactive oxygen species (ROS). This study demonstrated a correlation between STAT3 phosphorylation and cisplatin cytotoxicity, using AS2 (PC14PE6/AS2)-derived cell lines (AS2/S3C) that contained constitutively active STAT3 plasmids as a model. A STAT3 inhibitor (JSI-124) enhanced the cisplatin sensitivity in AS2 cells, whereas metformin inhibited STAT3 phosphorylation and enhanced cisplatin cytotoxicity. By contrast, another AMPK activator (5-aminoimidazole-4-carboxamide-riboside) failed to produce these effects. LKB1-AMPK silencing by small, interfering RNA or mammalian target of rapamycin (mTOR) inhibition by rapamycin or pp242 did not alter the effect of metformin on STAT3 activity suppression, suggesting that metformin can modulate the STAT3 pathway through an LKB1-AMPK-independent and probably mTOR-independent mechanism. Metformin also inhibited cisplatin-induced ROS production and autocrine IL-6 secretion in AS2 cells. Both mechanisms contributed to the ability of metformin to suppress STAT3 activation in cancer cells, which resulted in the decreased secretion of vascular endothelial growth factor by cancer cells. The growth of subcutaneous tumor xenografts was significantly delayed by a combination of cisplatin and metformin. This is the first study to demonstrate that metformin suppresses STAT3 activation via LKB1-AMPK-mTOR-independent but ROS-related and autocrine IL-6 production-related pathways. Thus, metformin helps to overcome tumor drug resistance by targeting STAT3.

Interleukin-17-producing cell infiltration in the breast cancer tumour microenvironment is a poor prognostic factor.

AIMS: Interleukin-17 (IL-17) is a proinflammatory cytokine that is most prominently produced by T-helper type 17 (Th17) cells, a distinct CD4+ T-helper cell subset. The aim of this study was to investigate the level of IL-17-producing cells in the breast cancer tumour microenvironment and its prognostic role. METHODS AND RESULTS: A total of 207 breast carcinoma specimens were assessed by IL-17 immunohistochemistry, and the findings were correlated with clinicopathological parameters. We found that increased numbers of IL-17-producing cells were correlated with high histological grade, negative ER/PR status, and triple-negative molecular subtypes segregated by immunoprofiles. However, they did not correlate with stage, tumour size, nodal status, HER2 status, or histological type. Patients with tumours with high numbers of IL-17-producing cells had shorter disease-free survival (DFS) than patients with tumours with low numbers of IL-17-producing cells (P < 0.01). In multivariate analysis, high IL-17 level [hazard ratio (HR) 2.24; 95% CI 1.06-4.75], advanced T stage (HR 2.73; 95% CI 1.30-5.73), positive HER2 status (HR 4.88; 95% CI 1.47-16.18) and triple-negative subtype (HR 7.46; 95% CI 1.38-40.36) were significant prognostic factors for DFS. CONCLUSIONS: Our results indicate that a high level of IL-17-producing cells in the breast cancer tumour microenvironment is a poor prognostic factor.

The increment in standardized uptake value determined using dual-phase 18F-FDG PET is a promising prognostic factor in non-small-cell lung cancer.

PURPOSE: We aimed to determine whether the increment in the maximal standardized uptake value (SUVmax) of the primary lung tumour between the initial and delayed imaging by dual-phase (18)F-FDG PET has prognostic value in patients with non-small-cell lung cancer (NSCLC). METHODS: We reviewed the records of patients with NSCLC who underwent pretreatment dual-phase (18)F-FDG PET/CT scans acquired at 1 h and 2 h after injection. The SUVmax increment (SUVinc) of the primary lung tumour was the 2-h SUVmax minus the 1-h SUVmax. Univariate and multivariate analyses were used to assess the prognostic significance of SUVinc, retention index, whole-body total metabolic tumour volume, whole-body total lesion glycolysis (TLGwb), 1-h SUVmax, 2-h SUVmax, gender, age, performance status, histological subtype, T stage, N stage and clinical stage. RESULTS: The records of 187 consecutive patients were reviewed. The median follow-up time was 3.9 years. The estimated median progression-free survival (PFS) and overall survival (OS) were 1.3 years and 4.4 years, respectively. An SUVinc cut-off value of >1 had the best discriminative yield for PFS. The 3-year PFS and OS were 61.6 % and 87.8 % in patients with SUVinc ≤ 1 versus 21.1 % and 46.2 % in patients with SUVinc >1 (all P < 0.01). Using the forward stepwise multivariate Cox proportional hazards model, SUVinc, TLGwb, and clinical stage were significant factors for PFS (all P < 0.01). A subgroup analysis of 117 patients treated with surgery showed that SUVinc (P = 0.02) and clinical stage (P < 0.01) were significant prognostic factors for PFS. Furthermore, in stage I patients treated with surgery alone, SUVinc was the only significant prognostic factor (HR 28.07; 95 % CI 2.42 - 326.41). CONCLUSION: SUVinc determined from dual-phase (18)F-FDG PET is a promising prognostic factor for NSCLC. It adds to the value of dual-phase (18)F-FDG PET.

Estimating the lifelong health impact and financial burdens of different types of lung cancer.

BACKGROUND: Owing to the high mortality and rapidly growing costs related to lung cancer, it is worth examining the health benefits of prevention for major types of lung cancer. This study attempts to quantify the quality-adjusted life expectancy (QALE), loss-of-QALE, and lifetime healthcare expenditures of patients with different pathological types of lung cancer. METHODS: A national cohort consisting of 66,535 patients with pathologically verified lung cancer was followed for 13 years (1998-2010) to obtain the survival function, which was further extrapolated to lifetime. Between 2011 and 2012, EuroQol 5-dimension questionnaires were used to measure the quality of life (QoL) for 1,314 consecutive, cross-sectional samples. After multiplying the lifetime survival function by the utility values of QoL, we estimated the QALE and loss-of-QALE. We also collected the monthly healthcare expenditures, which included National Health Insurance-reimbursed and out-of-pocket direct medical costs, for 2,456 patients from 2005 to 2012. These values were multiplied by the corresponding survival probabilities to calculate lifetime healthcare expenditures after adjustments with medical care inflation rates and annual discount rates. RESULTS: The QALE for patients with small cell lung cancer, squamous cell carcinoma, and adenocarcinoma were 1.21, 2.37, and 3.03 quality-adjusted life year (QALY), with the corresponding loss-of-QALE of 13.69, 12.22, and 15.03 QALY, respectively. The lifetime healthcare expenditures were US$ 18,455 ± 1,137, 20,599 ± 1,787, and 36,771 ± 1,998, respectively. CONCLUSIONS: The lifelong health impact and financial burdens in Taiwan are heavier for adenocarcinoma than for squamous cell carcinoma. The cost-effectiveness of prevention programs could be directly compared with that of treatment strategies to improve patient value. And the methodology could be applied to other chronic diseases for resources planning of healthcare services.

HER2 amplification in colorectal cancer with brain metastasis: A propensity score matching study.

BACKGROUND: The association between human epidermal growth factor receptor-2 (HER2) amplification and brain metastasis (BM) in patients having colorectal cancer (CRC) has been suggested but not yet established. This study investigated the expression patterns of HER2, its association with BM, and its prognostic value in patients having CRC. METHODS: We retrospectively identified 99 patients having metastatic CRC (mCRC) and BM (the BM cohort) and compared them with a cohort of 249 patients having mCRC and without BM (the stage IV cohort) by propensity score matching. Immunohistochemical studies of HER2 on all available paraffin-embedded tumour samples, either from the primary tumour, the metastasis (brain and/or extracranial sites) or both, were performed and analysed. HER2 fluorescent in situ hybridisation was applied when necessary. The expression of HER2 was compared and correlated with survival. RESULTS: HER2 amplifications were detected in 16 (18.4%) of 87 and 9 (3.6%) of 249 patients who had specimens available in the BM and stage IV cohorts, respectively (P < .001). After propensity score matching, HER2 amplification was significantly associated with BM (odds ratio: 5.38, P = .003). HER2 heterogeneity was frequently observed not only at the single tumour level but also in paired tumour samples. A marginally significant longer survival since BM was found in patients having HER2-amplified mCRC than in those without (P = .07). CONCLUSIONS: HER2 amplification was significantly associated with BM in patients having mCRC and might have prognostic value for survival since BM. Given the heterogeneity of HER2 expression, the testing of HER2 status on available tissues from both primary and metastatic tumours should be encouraged.

Mitochondrial uncoupling protein 2 regulates the effects of paclitaxel on Stat3 activation and cellular survival in lung cancer cells.

Growing evidence suggests that Stat3 contributes to chemoresistance. However, the impact of chemotherapy on Stat3 activity is unclear. We found that paclitaxel activated Stat3 in the human lung cancer cell lines PC14PE6AS2 (AS2) and H157, whereas it reduced Stat3 activation in A549 and H460 cells. Pretreatment of AS2 and H157 cells with rotenone, an inhibitor of mitochondrially produced reactive oxygen species (ROS), or carbonyl cyanide p-(trifluoromethoxy)-phenylhydrazone (FCCP), a mitochondrial uncoupler, suppressed the paclitaxel-induced activation of Stat3. Uncoupling protein 2 (UCP-2), located in the inner membrane of the mitochondria, can reduce ROS production in conditions of oxidative stress. UCP-2 protein expression in the four cancer cell lines was higher than that in normal lung epithelial cells (NL-20), but its expression was lower in AS2 and H157 cells relative to A549 and H460 cells. Silencing high UCP-2 expression with small interfering RNA (siRNA) in A549 and H460 cells restored paclitaxel-induced Stat3 activation. In addition, paclitaxel-induced Stat3 activation led to the upregulation of survivin and Mcl-1, which in turn facilitated cell survival. Moreover, the CL1-5 subline had lower UCP-2 expression relative to the parental CL1-0 cells. Treatment with paclitaxel activated Stat3 in CL1-5 but not in CL1-0 cells, whereas in CL1-5 cells, the overexpression of UCP-2 with complementary DNA (cDNA) blocked Stat3 activation. In lung cancer patients, low UCP-2 expression in cancer cells was a predictor of a poor response to chemotherapy. Therefore, UCP-2 modulates the ROS/Stat3 signaling pathway and response to chemotherapy treatment in lung cancer cells. Targeting UCP-2, ROS and Stat3 pathways may improve anticancer therapies.

Prognostic value of whole-body total lesion glycolysis at pretreatment FDG PET/CT in non-small cell lung cancer.

PURPOSE: To determine whether whole-body total lesion glycolysis (TLG), which combines volumetric and metabolic information from fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT), can provide a better evaluation of the prognosis for non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: The institutional review board approved this retrospective study, and the requirement to obtain informed consent was waived. The authors identified 105 consecutive patients with NSCLC who underwent staging FDG PET/CT before any therapy. These patients were free of brain metastasis and underwent standard treatment and subsequent clinical follow-up. Metabolic tumor volume (MTV), mean standardized uptake value (SUV), and maximum SUV of each tumor over the whole body were determined. Whole-body MTV and whole-body TLG are the summation of all the MTVs and summation of individual tumor volume multiplied by its mean SUV, respectively. Univariate and multivariate analyses were performed to assess the prognostic significance of whole-body TLG and other factors, including whole-body MTV, lung TLG, lung MTV, maximum SUV, sex, age, performance status, histologic subtype, T stage, N stage, clinical stage, and treatment method. RESULTS: The median follow-up time was 3.1 years. The estimated median progression-free survival (PFS) and overall survival (OS) for the cohort was 10.8 months and 2.8 years, respectively. The 1-year PFS was 0.0% for patients with high whole-body TLG (>655) and 50.0% for those with low whole-body TLG (≤655). The 1-year OS was 58.8% for patients with high whole-body TLG and 84.1% for those with low whole-body TLG. Univariate analysis showed that whole-body TLG, whole-body MTV, lung TLG, lung MTV, maximum SUV, performance status, T stage, N stage, clinical stage, and treatment type (surgery vs other) were significant prognostic factors for PFS (P < .01 for all). With use of the forward stepwise multivariate Cox proportional hazards model, whole-body TLG (hazard ratio = 2.92; 95% confidence interval: 1.62, 5.26; P < .01) and surgical treatment (hazard ratio = 4.24; 95% confidence interval: 2.54, 7.07; P < .01) remained significant in PFS. CONCLUSION: Whole-body TLG is of prognostic value for NSCLC. It may be a promising tool for stratifying patients with NSCLC for risk-adapted therapies.

Impact of Alcohol and Smoking on Outcomes of HPV-Related Oropharyngeal Cancer.

BACKGROUND: The aim of this study was to evaluate the impact of adverse lifestyle factors on outcomes in patients with human papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (OPSCC). METHODS: From 2010 to 2019, 150 consecutive non-metastatic OPSCC patients receiving curative treatment in our institution were retrospectively enrolled. HPV positivity was defined as p16 expression ≥75%. The effects of adverse lifestyle factors on overall survival (OS) and disease-free survival (DFS) on OPSCC patients were determined. RESULTS: The median follow-up duration was 3.6 years. Of the 150 OPSCCs, 51 (34%) patients were HPV-positive and 99 (66%) were HPV-negative. The adverse lifestyle exposure rates were 74.7% (n = 112) alcohol use, 57.3% (n = 86) betel grid chewing, and 78% (n = 117) cigarette smoking. Alcohol use strongly interacted with HPV positivity (HR, 6.00; 95% CI, 1.03-35.01), leading to an average 26.1% increased risk of disease relapse in patients with HPV-positive OPSCC. Heavy smoking age ≥30 pack-years was associated with increased risk of death (HR, 2.05; 95% CI, 1.05-4.00) and disease relapse (HR, 1.99; 95% CI, 1.06-3.75) in OPSCC patients. In stratified analyses, the 3-year absolute risk of disease relapse in HPV-positive OPSCC patients reached up to 50% when alcohol use and heavy smoking for ≥30 pack-years were combined. CONCLUSIONS: Alcohol acted as a significant treatment-effect modifier for DFS in HPV-positive OPSCC patients, diluting the favorable prognostic effect of HPV positivity. Heavy smoking age ≥30 pack-years was an independent adverse prognostic factor of OS and DFS in OPSCC patients. De-intensification treatment for HPV-related OPSCC may be avoided when these adverse lifestyle factors are present.

Accelerated coronary calcium burden in breast cancer patients after radiotherapy: a comparison with age and race matched healthy women.

BACKGROUND: Radiotherapy (RT) might lead to atherosclerotic plaque buildup and coronary artery stenosis of breast cancer (BC) survivors, and coronary artery calcium (CAC) might be a sign of preclinical atherosclerosis. This study explores possible determinants affecting the acceleration of CAC burden in BC patients after adjuvant RT. METHODS: Female BC patients receiving adjuvant RT from 2002 to 2010 were included. All patients received noncontrast computed tomography (NCCT) of thorax before and after adjuvant RT. Their CAC burden was compared with healthy controls from the Multi-Ethnic Study of Atherosclerosis (MESA) cohort. The progression of the CAC burden was manifested by the increment of CAC percentiles (%CACinc). RESULTS: Ninety-four patients, including both left- and right-side BC, were enrolled in this study. From undergoing the first to second NCCT, the %CACinc in BC patients significantly increased rather than non-BC women. In addition, the %CACinc was significantly higher in left-side than right-side BC patients (p < 0.05), and significant differences in most heart outcomes were found between the two groups. Besides, the lower the mean right coronary artery (RCA) dose, the lower the risks of CAC percentiles increase ≥ 50% after adjusting the disease's laterality. CONCLUSIONS: A significantly higher accelerated CAC burden in BC patients than non-BC women represents that BC could affect accelerated CAC. A higher risk of accelerated CAC burden was found in left-side than right-side BC patients after adjuvant RT. A decrease of the mean RCA dose could reduce more than 50% of the risk of accelerated CAC burden in BC patients.

Targeting the Proline-Glutamine-Asparagine-Arginine Metabolic Axis in Amino Acid Starvation Cancer Therapy.

Proline, glutamine, asparagine, and arginine are conditionally non-essential amino acids that can be produced in our body. However, they are essential for the growth of highly proliferative cells such as cancers. Many cancers express reduced levels of these amino acids and thus require import from the environment. Meanwhile, the biosynthesis of these amino acids is inter-connected but can be intervened individually through the inhibition of key enzymes of the biosynthesis of these amino acids, resulting in amino acid starvation and cell death. Amino acid starvation strategies have been in various stages of clinical applications. Targeting asparagine using asparaginase has been approved for treating acute lymphoblastic leukemia. Targeting glutamine and arginine starvations are in various stages of clinical trials, and targeting proline starvation is in preclinical development. The most important obstacle of these therapies is drug resistance, which is mostly due to reactivation of the key enzymes involved in biosynthesis of the targeted amino acids and reprogramming of compensatory survival pathways via transcriptional, epigenetic, and post-translational mechanisms. Here, we review the interactive regulatory mechanisms that control cellular levels of these amino acids for amino acid starvation therapy and how drug resistance is evolved underlying treatment failure.

Targeting the Copper Transport System to Improve Treatment Efficacies of Platinum-Containing Drugs in Cancer Chemotherapy.

The platinum (Pt)-containing antitumor drugs including cisplatin (cis-diamminedichloroplatinum II, cDDP), carboplatin, and oxaliplatin, have been the mainstay of cancer chemotherapy. These drugs are effective in treating many human malignancies. The major cell-killing target of Pt drugs is DNA. Recent findings underscored the important roles of Pt drug transport system in cancer therapy. While many mechanisms have been proposed for Pt-drug transport, the high-affinity copper transporter (hCtr1), Cu chaperone (Atox1), and Cu exporters (ATP7A and ATP7B) are also involved in cDDP transport, highlighting Cu homeostasis regulation in Pt-based cancer therapy. It was demonstrated that by reducing cellular Cu bioavailable levels by Cu chelators, hCtr1 is transcriptionally upregulated by transcription factor Sp1, which binds the promoters of Sp1 and hCtr1. In contrast, elevated Cu poisons Sp1, resulting in suppression of hCtr1 and Sp1, constituting the Cu-Sp1-hCtr1 mutually regulatory loop. Clinical investigations using copper chelator (trientine) in carboplatin treatment have been conducted for overcoming Pt drug resistance due in part to defective transport. While results are encouraging, future development may include targeting multiple steps in Cu transport system for improving the efficacies of Pt-based cancer chemotherapy. The focus of this review is to delineate the mechanistic interrelationships between Cu homeostasis regulation and antitumor efficacy of Pt drugs.

Association of Primary Treatment Modality for Advanced-Stage Oropharyngeal Squamous Cell Carcinoma With Survival Outcomes.

Importance: Definitive chemoradiotherapy and upfront surgical treatment are both accepted as the standard of care for advanced-stage oropharyngeal squamous cell carcinoma. However, the optimal primary treatment modality remains unclear. Objective: To evaluate the comparative effectiveness of definitive chemoradiotherapy and upfront surgical treatment for advanced-stage oropharyngeal cancer. Design, Setting, and Participants: This retrospective comparative effectiveness analysis used data from the population-based Taiwan Cancer Registry. Included patients were diagnosed with clinical stage III or IV oropharyngeal squamous cell carcinoma from 2007 to 2015 and were identified from the registry. Patients with T4b or N3 disease were excluded. Data were analyzed from June 2019 through December 2020. Interventions: Definitive chemoradiotherapy or upfront surgical treatment. Main Outcomes and Measures: The primary outcome was overall survival, for which data were available through December 31, 2018. Secondary outcomes were progression-free survival, locoregional recurrence-free survival, and distant metastasis-free survival. Results: Among 1180 patients, 694 patients (58.8%) were in the definitive chemoradiotherapy group and 486 patients (41.2%) were in the upfront surgical treatment group. The median (interquartile range) follow-up was 3.62 (1.63-5.47) years, and most patients were men (1052 [89.1%] men) with a primary tumor in the tonsils (712 patients [60.3%]), moderately differentiated histology (604 patients [51.2%]), clinical N2 disease (858 patients [72.7%]), and clinical stage IVA disease (938 patients [79.5%]). The mean (SD) age was 54.59 (10.35) years. Primary treatment with an upfront surgical procedure was associated with a decreased risk of death during the study period (hazard ratio [HR], 0.81; 95% CI, 0.69-0.97; P = .02). However, when adjusted for age, subsite, histological grade, and T and N classification, upfront surgical treatment was no longer associated with an increased risk of death during the study period (HR, 0.96; 95% CI, 0.80-1.16; P = .70). Progression-free survival was worse in the group receiving upfront surgical treatment than in the group receiving chemoradiotherapy (HR, 1.64; 95% CI, 1.09-2.46; P = .02), and this difference persisted after adjusting for other factors associated with prognosis (ie, age, tumor subsite, histological grade, and T and N classification) (HR, 1.72; 95% CI, 1.12-2.66; P = .01). Conclusions and Relevance: This study found that definitive chemoradiotherapy was associated with effectiveness that was comparable with that of upfront surgical treatment when adjusted for baseline factors associated with prognosis. These findings suggest that definitive chemoradiotherapy should be considered to avoid accumulating toxic effects associated with surgical treatment and chemoradiotherapy.

Single cell phospho-specific flow cytometry can detect dynamic changes of phospho-Stat1 level in lung cancer cells.

Single cell phospho-specific flow cytometry (SCPFC) enables the investigation of signaling network interactions and the categorization of disease outcome. While this method has been successfully used to study hematologic disorders, its application on solid tumors has not been examined. This study aimed to demonstrate the ability of SCPFC to detect dynamic changes of Tyrosine phospho-Stat1 (pStat1) in solid tumor models and in human tumor samples. In the human lung cancer cell line PC14PE6/AS2, the fluorescence intensity changes of pStat1 after IFN-γ stimulation were compatible to results obtained by Western blot analysis. In metastatic animal models, cancer cells from subcutaneous tumors, malignant ascites, and peritoneal tumors responded to IFN-γ. The pStat1 was activated in these cells after IFN-γ stimulation, with a 1.5- to 2.5-fold increase in fluorescence intensity compared to the unstimulated control. To examine the potential clinical application of SCPFC, cancer cells were collected from malignant pleural effusions (MPEs) of lung cancer patients to observe the activation of pStat1 after IFN-γ stimulation. Cell apoptosis after cisplatin treatment was evaluated by Annexin V staining, which showed that MPE cancer cells with higher pStat1 changes after IFN-γ stimulation were more resistant to cisplatin. In conclusion, there is a preliminary application of SCPFC to solid tumors and links to drug sensitivity are promising.

Collaboration Between RSK-EphA2 and Gas6-Axl RTK Signaling in Arginine Starvation Response That Confers Resistance to EGFR Inhibitors.

Many human malignancies require extracellular arginine (Arg) for survival because the key enzyme for de novo Arg biosynthesis, argininosuccinate synthetase 1 (ASS1), is silenced. Recombinant arginine deiminase (ADI-PEG20), which digests extracellular Arg, has been in clinical trials for treating ASS1-negative tumors. Reactivation of ASS1 is responsible for the treatment failure. We previously demonstrated that ASS1 reactivation is transcriptionally regulated by c-Myc via the upstream Gas6-Axl tyrosine kinase (RTK) signal. Here, we report that another RTK EphA2 is coactivated via PI3K-ERK/RSK1 pathway in a ligand-independent mechanism. EphA2 is also regulated by c-Myc. Moreover, we found that knockdown Axl upregulates EphA2 expression, demonstrating cross-talk between these RTKs. ADIR cell lines exhibits enhanced sensitivities to nutrient deprivation such as charcoal-stripped FBS and multiple RTK inhibitor foretinib but resistance to EGFR inhibitors. Knockdown EphA2, and to lesser extent, Axl, overcomes EGFRi resistance. c-Myc inhibitor JQ1 can also sensitize ADIR cells to ADI-PEG20. This study elucidates molecular interactions of multiple RTKs in Arg-stress response and offers approaches for developing strategies of overcoming ADI-PEG20 resistance.

Prognostic value of volumetric metabolic parameter changes determined by during and after radiotherapy-based 18 F-FDG PET/CT in stage III non-small cell lung cancer.

The aim of this prospective study was to evaluate the prognostic value of volumetric metabolic parameters assessed by during and after radiation-based therapy 18 F-FDG PET/CT in patients with stage III non-small cell lung cancer (NSCLC). We enrolled stage III NSCLC patients who had planned to receive definitive chemo-radiation or radiotherapy (RT) and underwent 18 F-FDG PET/CT before treatment (PET1), during RT (at the fifth week, PET2) and after treatment (3 months later, PET3). By comparing with PET1, percentage changes of metabolic tumor volume (ΔMTV) and tumor total lesion glycolysis (ΔTLG) of PET2 and PET3 were calculated. We used medians of ΔTLG and ΔMTV as cut-off values to stratify patients. Their prognostic values were evaluated by progression-free survival (PFS) and overall survival (OS). Thirty patients were enrolled initially. Five were excluded due to multiple metastases or double cancer. The remaining 25 patients had PET2 at a median of 46 Gy. Data on PET3 were available in 19 patients. During-RT ΔTLG (cut-off: 65%) was a significant prognostic factor for PFS (P = 0.02) and OS (P < 0.01). During-RT ΔMTV (cut-off: 42%) had marginal significance for PFS (P = 0.07) and was significant for OS (P = 0.02). Of the PET3 parameters, neither ΔTLG nor ΔMTV was a significant prognostic factor for PFS and OS. We conclude that ΔTLG of during-RT 18 F-FDG PET/CT may predict treatment response and thus provide opportunities to modify treatment for poor responders.

Transcription factor Sp1 plays an important role in the regulation of copper homeostasis in mammalian cells.

Copper is an essential metal nutrient, yet copper overload is toxic. Here, we report that human copper transporter (hCtr) 1 plays an important role in the maintenance of copper homeostasis by demonstrating that expression of hCtr1 mRNA was up-regulated under copper-depleted conditions and down-regulated under copper-replete conditions. Overexpression of full-length hCtr1 by transfection with a recombinant hCtr1 cDNA clone reduced endogenous hCtr1 mRNA levels, whereas overexpression of N terminus-deleted hCtr1 did not change endogenous hCtr1 mRNA levels, suggesting that increased functional hCtr1 transporter, which leads to increased intracellular copper content, down-regulates the endogenous hCtr1 mRNA. A luciferase assay using reporter constructs containing the hCtr1 promoter sequences revealed that three Sp1 binding sites are involved in the basal and copper concentration-dependent regulation of hCtr1 expression. Modulation of Sp1 levels affected the expression of hCtr1. We further demonstrated that the zinc-finger domain of Sp1 functions as a sensor of copper that regulates hCtr1 up and down in response to copper concentration variations. Our results demonstrate that mammalian copper homeostasis is maintained at the hCtr1 mRNA level, which is regulated by the Sp1 transcription factor.