ZNF689 deficiency promotes intratumor heterogeneity and immunotherapy resistance in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is an aggressive disease characterized by remarkable intratumor heterogeneity (ITH), which poses therapeutic challenges. However, the clinical relevance and key determinant of ITH in TNBC are poorly understood. Here, we comprehensively characterized ITH levels using multi-omics data across our center's cohort (n = 260), The Cancer Genome Atlas cohort (n = 134), and four immunotherapy-treated cohorts (n = 109). Our results revealed that high ITH was associated with poor patient survival and immunotherapy resistance. Importantly, we identified zinc finger protein 689 (ZNF689) deficiency as a crucial determinant of ITH formation. Mechanistically, the ZNF689-TRIM28 complex was found to directly bind to the promoter of long interspersed element-1 (LINE-1), inducing H3K9me3-mediated transcriptional silencing. ZNF689 deficiency reactivated LINE-1 retrotransposition to exacerbate genomic instability, which fostered ITH. Single-cell RNA sequencing, spatially resolved transcriptomics and flow cytometry analysis confirmed that ZNF689 deficiency-induced ITH inhibited antigen presentation and T-cell activation, conferring immunotherapy resistance. Pharmacological inhibition of LINE-1 significantly reduced ITH, enhanced antitumor immunity, and eventually sensitized ZNF689-deficient tumors to immunotherapy in vivo. Consistently, ZNF689 expression positively correlated with favorable prognosis and immunotherapy response in clinical samples. Altogether, our study uncovers a previously unrecognized mechanism underlying ZNF689 deficiency-induced ITH and suggests LINE-1 inhibition combined with immunotherapy as a novel treatment strategy for TNBC.

DNAzyme-based faithful probing and pulldown to identify candidate biomarkers of low abundance

Biomarker discovery is essential for the understanding, diagnosis, targeted therapy and prognosis assessment of malignant diseases. However, it remains a huge challenge due to the lack of sensitive methods to identify disease-specific rare molecules. Here we present MORAC, molecular recognition based on affinity and catalysis, which enables the effective identification of candidate biomarkers with low abundance. MORAC relies on a class of DNAzymes, each cleaving a sole RNA linkage embedded in their DNA chain upon specifically sensing a complex system with no prior knowledge of the system's molecular content. We show that signal amplification from catalysis ensures the DNAzymes high sensitivity (for target probing); meanwhile, a simple RNA-to-DNA mutation can shut down their RNA cleavage ability and turn them into a pure affinity tool (for target pulldown). Using MORAC, we identify previously unknown, low-abundance candidate biomarkers with clear clinical value, including apolipoprotein L6 in breast cancer and seryl-tRNA synthetase 1 in polyps preceding colon cancer.

Abstract GS5-05: ZNF689 deficiency promotes intratumor heterogeneity and resistance to immune checkpoint blockade in triple-negative breast cancer

Background: Triple-negative breast cancer (TNBC) is an aggressive disease characterized by remarkable intratumor heterogeneity (ITH), which poses a significant therapeutic challenge. However, the key determinants and underlying mechanisms of ITH in TNBC remain to be fully elucidated. Methods: We used multi-omics data from our cohort (n = 260) and The Cancer Genome Atlas (n = 134) cohort to comprehensively characterize ITH at the genetic and histologic levels. Transcriptomic differences between high ITH and low ITH tumors were compared to identify the core genes contributing ITH in TNBC. Xenograft models were used to examine the role of key determinants in TNBC ITH. The molecular mechanism was investigated by mass spectrometry, coimmunoprecipitation, pull-down, RNA-seq, long interspersed element-1 (LINE-1) reporter, ATAC-seq, luciferase reporter assays, chromatin immunoprecipitation, flow cytometry and coculture assay. Results: We found that high ITH was associated with poor patient survival and immune checkpoint blockade (ICB) resistance, which were validated in four independent ICB-treated trials. Further analysis indicated zinc finger protein 689 (ZNF689) deficiency as an important determinant of TNBC ITH. Mechanistically, the ZNF689-TRIM28 complex directly bound to the promoter of LINE-1, inducing H3K9me3-mediated transcriptional silencing. ZNF689 deficiency reactivated LINE-1 retrotransposition to exacerbate genomic instability, which promoted ITH. ZNF689 deficiency-induced ITH inhibited antigen presentation and CD8+ T cell infiltration, leading to ICB resistance. Pharmacological inhibition of LINE-1 retrotransposition reduced ITH, augmented antitumor immunity, and eventually sensitized ZNF689-deficient tumors to ICB. Consistently, ZNF689 expression positively correlated with favorable prognosis and ICB responsiveness in clinical samples. Conclusions: Our study uncovers a new mechanism underlying ZNF689 deficiency-induced ITH and suggests LINE-1 inhibition combined with ICB as a novel treatment strategy in TNBC.

Citation Format: Li-Ping Ge, Xi Jin, Gen-Hong Di, Yi-Zhou Jiang, Zhi-Ming Shao. ZNF689 deficiency promotes intratumor heterogeneity and resistance to immune checkpoint blockade in triple-negative breast cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr GS5-05.

Deposition of resistant bacteria and resistome through FMT in germ-free piglets

Faecal microbiota transplantation (FMT) has received considerable attention in recent years due to its remarkable efficacy in restoring a normal gut microbiome. Here, we established the groups of post-FMT recipient piglets using germ-free piglets during early life to characterize the colonization of gut microbiota composition and the enrichment of resistance gene acquisition. By metagenomic analysis, we identified 115 bacterial phyla and 2111 bacterial genera that were acquired by the FMT recipients. We found that early-life microbial colonization and the spread of resistomes in recipient piglets were age dependent. A total of 425, 425 and 358 AR genes primarily belonging to 114, 114 and 102 different types were detected in the donors, post-FMT recipients in the FMT-3D group and post-FMT recipients in the FMT-15D group respectively. Genes that encoded tetracycline, macrolide and chloramphenicol resistance proteins were the most dominant AR genes, and the results corresponded with the exposure of antibiotic consumption at farm. Bacteroides, Escherichia, Clostridium, Parabacteroides, Treponema, Lactobacillus and Enterococcus were significantly correlated with the distribution of AR genes. More importantly, the relative abundance of AR genes was positively correlated with the levels of mobile genetic elements. Our results indicate that early-life microbial colonization can persistently shape the gut microbiota and antibiotic resistome.

The plastome of Phaius hainanensis (Orchidaceae): an endangered species endemic to Hainan province, China

Phaius hainanensis C. Z. Tang et S. J. Cheng is a species with extremely small populations and is endemic to China. Genetic data of this orchid species is minimal. With the aim to identify appropriate chloroplast markers for the use in conservation biology studies, the plastome of P. hainanenisis was assembled. The plastome of P. hainanensis is 158,314 bp in length and contains a large single copy region of 86,700 bp in length, a small single copy region of 18,452 bp, and a pair of inverted repeats of 26,581 bp. The annotation predicted 114 unique genes, including 80 protein-coding, 30 tRNAs, and four rRNAs. Seventeen genes contained a single intron and two genes (clpP and ycf3) have two introns. The GC content of P. hainanensis is 36.9%. Phylogenetic analysis indicated P. hainanensis is closely related to P. tancarvilleae, and it also supported that Phaius and Calanthe are sister groups. The plastome data reported in this study will contribute to further studies of phylogeny and conservation of Phaius species.

Tektin4 loss promotes triple-negative breast cancer metastasis through HDAC6-mediated tubulin deacetylation and increases sensitivity to HDAC6 inhibitor

Progression of triple-negative breast cancer (TNBC) constitutes a major unresolved clinical challenge, and effective targeted therapies are lacking. Because microtubule dynamics play pivotal roles in breast cancer metastasis, we performed RNA sequencing on 245 samples from TNBC patients to characterize the landscape of microtubule-associated proteins (MAPs). Here, our transcriptome analyses revealed that low expression of one MAP, tektin4, indicated poor patient outcomes. Tektin4 loss led to a marked increase in TNBC migration, invasion, and metastasis and a decrease in microtubule stability. Mechanistically, we identified a novel microtubule-associated complex containing tektin4 and histone deacetylase 6 (HDAC6). Tektin4 loss increased the interaction between HDAC6 and α-tubulin, thus decreasing microtubule stability through HDAC6-mediated tubulin deacetylation. Significantly, we found that tektin4 loss sensitized TNBC cells, xenograft models, and patient-derived organoid models to the HDAC6-selective inhibitor ACY1215. Furthermore, tektin4 expression levels were positively correlated with microtubule stability levels in clinical samples. Together, our findings uncover a metastasis suppressor function of tektin4 and support clinical development of HDAC6 inhibition as a new therapeutic strategy for tektin4-deficient TNBC patients.

The complete chloroplast genome of an endangered orchid Paphiopedilum spicerianum

Paphiopedilum spicerianum (H. G. Reichenbach) Pfitzer is an endangered and threatened orchid species in China. The genetic and molecular data of this orchid species is deficient. With the aim to identify appropriate chloroplast markers for the use in a conservation biology study, the complete chloroplast genome of P. spicerianum was reported. We found that the chloroplast genome of P. spicerianum is 157,292 bp in length, containing a large single-copy region of 87,252 bp, a small single-copy region of 1828 bp, and a pair of inverted repeats of 34,106 bp. Genome annotation predicted 105 unique genes, including 71 protein-coding genes, 30 tRNAs, and four rRNAs. Fourteen genes contained one intron and two genes (clpP and ycf3) had two introns. The GC content of the P. spicerianum was 35.8%. Phylogenetic analysis indicated P. spicerianum was closely related to P. purpuratum.

Randomized phase II clinical trial and biomarker analysis of paclitaxel plus epirubicin versus vinorelbine plus epirubicin as neoadjuvant chemotherapy in locally advanced HER2-negative breast cancer with TEKT4 variations

PURPOSE

Resistance to paclitaxel remains a major challenge in treating breast cancer. Our preclinical study suggested that TEKT4 germline variations in breast cancer are associated with paclitaxel resistance and increase vinorelbine sensitivity. This clinical trial compared the efficacy of paclitaxel and vinorelbine in breast cancer neoadjuvant chemotherapy.

METHODS

In this open-label, single-center, phase II trial, female patients with human epidermal growth factor receptor 2 (HER2)-negative, stage IIB-IIIC breast cancer harboring TEKT4 germline variations were randomly assigned to the paclitaxel plus epirubicin (PE) or vinorelbine plus epirubicin (NE). The primary endpoint was the pathologic complete response (pCR) rate, and the secondary endpoints were the objective response rate (ORR) and safety. Targeted sequencing of a panel comprising 484 breast-related genes was performed to identify pCR-associated somatic mutations in each group.

RESULTS

91 Patients were assigned to PE (46 patients) or NE (45 patients). NE numerically increased the pCR rate (22.2% versus 8.7%, P = 0.074). The ORRs for NE and PE were 82.2% and 76.1%, respectively. Interestingly, NE (15.4%) showed a significantly higher pCR rate than PE (0%) in the hormone receptor (HR)-positive subgroup (P = 0.044). Both regimens were well tolerated, with grade 3 and 4 toxicities reported at the expected levels. The biomarker analysis showed that UNC13D mutation predicted the pCR rate in NE (P = 0.011).

CONCLUSIONS

Although the primary endpoint was not met, NE might bring clinical benefit to HR-positive patients or patients simultaneously carrying UNC13D mutations.

SYTL4 downregulates microtubule stability and confers paclitaxel resistance in triple-negative breast cancer

Background: Taxanes are frontline chemotherapeutic drugs for patients with triple-negative breast cancer (TNBC); however, chemoresistance reduces their effectiveness. We hypothesized that the molecular profiling of tumor samples before and after neoadjuvant chemotherapy (NAC) would help identify genes associated with drug resistance.

Methods: We sequenced 10 samples by RNA-seq from 8 NAC patients with TNBC: 3 patients with a pathologic complete response (pCR) and the other 5 with non-pCR. Differentially expressed genes that predicted chemotherapy response were selected for in vitro functional screening via a small-scale siRNAs pool. The clinical and functional significance of the gene of interest in TNBC was further investigated in vitro and in vivo, and biochemical assays and imaging analysis were applied to study the mechanisms.

Results: Synaptotagmin-like 4 (SYTL4), a Rab effector in vesicle transport, was identified as a leading functional candidate. High SYTL4 expression indicated a poor prognosis in multiple TNBC cohorts, specifically in taxane-treated TNBCs. SYTL4 was identified as a novel chemoresistant gene as validated in TNBC cells, a mouse model and patient-derived organoids. Mechanistically, downregulating SYTL4 stabilized the microtubule network and slowed down microtubule growth rate. Furthermore, SYTL4 colocalized with microtubules and interacted with microtubules through its middle region containing the linker and C2A domain. Finally, we found that SYTL4 was able to bind microtubules and inhibit the in vitro microtubule polymerization.

Conclusion: SYTL4 is a novel chemoresistant gene in TNBC and its upregulation indicates poor prognosis in taxane-treated TNBC. Further, SYTL4 directly binds microtubules and decreases microtubule stability.

LncRNA TROJAN promotes proliferation and resistance to CDK4/6 inhibitor via CDK2 transcriptional activation in ER+ breast cancer

Background

Estrogen receptor-positive (ER+) breast cancers represent approximately two-thirds of all breast cancers and have a sustained risk of late disease recurrence. Cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors have shown significant efficacy in ER+ breast cancer. However, their effects are still limited by drug resistance. In this study, we aim to explore the role of long noncoding RNA TROJAN in ER+ breast cancer.

Methods

The expression level of TROJAN in breast cancer tissue and cell lines was determined by quantitative real-time PCR. In vitro and in vivo assays as well as patient derived organoid were preformed to explore the phenotype of TROJAN in ER+ breast cancer. The TROJAN-NKRF-CDK2 axis were screened and validated by RNA pull-down, mass spectrometry, RNA immunoprecipitation, microarray, dual-luciferase reporter and chromatin immunoprecipitation assays.

Results

Herein, we showed that TROJAN was highly expressed in ER+ breast cancer. TROJAN promoted cell proliferation and resistance to a CDK4/6 inhibitor and was associated with poor survival in ER+ breast cancer. TROJAN can bind to NKRF and inhibit its interaction with RELA, upregulating the expression of CDK2. The inhibition of TROJAN abolished the activity of CDK2, reversing the resistance to CDK4/6 inhibitor. A TROJAN antisense oligonucleotide sensitized breast cancer cells and organoid to the CDK4/6 inhibitor palbociclib both in vitro and in vivo.

Conclusions

TROJAN promotes ER+ breast cancer proliferation and is a potential target for reversing CDK4/6 inhibitor resistance.

Finding a resveratrol analogue as potential anticancer agent with apoptosis and cycle arrest

Resveratrol has been extensively studied as the anti-cancer agent. A variety of resveratrol analogues have been developed with structural modification to improve its bioactivity. In this work, resveratrol analogues, compound 1-4, were designed and synthesized with the Stille-Heck reaction. These results showed compound 1-4 had better anticancer effect than that of parent resveratrol. Especially compound 1 ((E)-4,4'-(ethene-1,2-diyl)bis(3-methylphenol)) displayed the excellent cytotoxicity and high selectivity. The mechanism research indicated compound 1 inhibited cell proliferation by binary paths of cell cycle arrest in S phase regulated by cyclin A1/A2 and apoptosis induction mediated by Bax/Bcl2 in a prooxidant manner.

Finding an efficient tetramethylated hydroxydiethylene of resveratrol analogue for potential anticancer agent

With the improvement and advance in cancer diagnosis and treatment, the cancer is still a major cause of morbidity and mortality throughout the world. Obviously, new breakthroughs in therapies remain be urgent needed. In this work, we designed and synthesized the compound 1-4, namely resveratrol analogues with methylation of hydroxy distyrene, to further explore its new anti-cancer potential. Encouragingly, compound 1 ((E)-4,4'-(ethene-1,2-diyl)bis(3,5-dimethylphenol)) exhibited cytotoxicity superior to resveratrol in MCF 7 cells. More importantly, the compound 1 showed greater toxicity to tumor cells than that to normal cells, which proved that it could selectively kill tumor cells. The favorable results encouraged us to explore the inhibitory mechanism of compound 1 on MCF 7 cells. The research finding indicated the compound 1 inhibited tumor cell proliferation by both arresting cell cycle in S phase and apoptosis via a prooxidant manner. In addition, the results further verified compound 1 caused cell cycle arrest in S phase and apoptosis by down-regulation of the cycling A1/cycling A2 expression and the rise of Bax/Bcl-2 ratio in a p21-dependant pathway in MCF 7 cells. Therefore, these results are helpful for the effective design of anticancer reagents and the better understanding of their mechanism of action.

Clinicopathological characteristics and treatment outcomes of occult breast cancer: a SEER population-based study

Background

Occult breast cancer (OBC) is a rare type of breast cancer that has not been well studied. The clinicopathological characteristics and treatment recommendations for OBC are based on a limited number of retrospective studies and thus remain controversial.

Patients and methods

We identified 479 OBC patients and 115,739 non-OBC patients from 2004 to 2014 in and the Surveillance, Epidemiology, and End Results (SEER) database. The clinicopathological characteristics and survival outcomes were compared between OBC and non-OBC patients. We used the propensity score 1:1 matching analysis to evaluate OBC vs non-OBC comparison using balanced groups with respect to the observed covariates. We further divided the OBC population into four groups based on different treatment strategies. Univariable and multivariable analyses were used to calculate and compare the four treatment outcomes within the OBC population.

Results

OBC patients were older, exhibited a more advanced stage, a higher rate of negative estrogen receptor and progesterone receptor status, a higher rate of HER2-positive status, and a higher rate of ≥10 positive lymph nodes, and were less likely to undergo surgical treatment than non-OBC patients. After adjustments for clinicopathological factors, the OBC patients exhibited a significantly better survival than the non-OBC patients (P<0.001). This result was confirmed in a 1:1 matched case–control analysis. Within the four OBC treatment groups, we observed no difference in survival among the mastectomy group, the breast-conserving surgery (BCS) group, and the axillary lymph node dissection (ALND)-only group. The multivariable analysis revealed that the sentinel lymph node dissection-only group had the worst prognosis (P<0.001). Conclusion: OBC has unique clinicopathological characteristics and a favorable prognosis compared with non-OBC. BCS plus ALND and radiotherapy showed a survival benefit that was similar to that of mastectomy for OBC patients.

A near-infrared fluorescent probe for direct and selective detection of cysteine over homocysteine and glutathione

In this work, we have designed and synthesized the fluorescent probe 1, which showed a highly selective and sensitive response to Cys over Hcy/GSH in the test. Moreover, the color of probe solution has changed dramatically from colorless to pink with the addition of Cys within 10 min. Meanwhile, the fluorescence intensity exhibited perfectly positive correlation with concentration of Cys from 0 to 200 μM, which offered the important condition for quantitative analysis. Finally, the bioimaging and fluorescence response of probe 1 for fetal calf serum are a powerful safeguard for practical detection of Cys. Therefore, this near-infrared probe will be of great benefit for detecting Cys in the biological systems.

Selective Fluorescent Detection of Cysteine over Homocysteine and Glutathione by a Simple and Sensitive Probe

A simple fluorescent probe able to selectively and sensitively detect cysteine (Cys) with an excellent dose-dependent relationship between fluorescence intensity and concentration of Cys from 0 to 100 μM has been designed and synthesised.

Chain elongation analog of resveratrol as potent cancer chemoprevention agent

Resveratrol is identified as a natural cancer chemoprevention agent. There has been a lot of interest in designing and developing resveratrol analogs with cancer chemoprevention activity superior to that of parent molecule and exploring their action mechanism in the past several decades. In this study, we have synthesized resveratrol analogs of compounds A-C via conjugated chain elongation based on isoprene unit retention strategy. Remarkably, cytotoxic activity analysis results indicated that compound B possesses the best proliferation inhibition activity for NCI-H460 cells in all the test compounds. Intriguingly, compound B displayed a higher cytotoxicity against human non-small cell lung cancer cells (NCI-H460) compared to normal human embryonic lung fibroblasts (MRC-5). Afterward, flow cytometry analysis showed that compound B would induce cell apoptosis. We further researched the action mechanism. When NCI-H460 cells were incubated by compound B for 6 or 9 h, respectively, the intracellular reactive oxygen species (ROS) level was enhanced obviously. With elevation of intracellular ROS level, flow cytometry measurement verified mitochondrial transmembrane potential collapse, which was accompanied by the up-regulation of Bax and down-regulation of Bcl-2. More interestingly, compound B increased the expression of caspase-9 and caspase-3, which induced cell apoptosis. Moreover, compound B arrested cell cycle in G0/G1 phase. These are all to provide useful information for designing resveratrol-based chemoprevention agent and understanding the action mechanism.

Survivin mRNA expression in blood as a predictor of the response to EGFR-tyrosine kinase inhibitors and prognosis in patients with non-small cell lung cancer

The epidermal growth factor receptor (EGFR) mutations have been proven to be a reliable predictive marker for the response to EGFR-tyrosine kinase inhibitors (TKIs) in patients with non-small cell lung cancer (NSCLC). However, the responses to EGFR-TKIs vary even among patients with EGFR mutation. Recent study showed that survivin overexpression attenuated EGFR-TKI-induced apoptosis and inhibited the antitumor effect of EGFR-TKIs on EGFR mutation NSCLC cells. We investigated the role of survivin mRNA expression in peripheral blood on predicting response and prognosis in NSCLC patients treated with EGFR-TKIs. Survivin mRNA expression levels in blood was detected using quantitative real-time-PCR assay in 62 patients with advanced NSCLC before (D0) and 4 weeks after treatment of EGFR-TKIs (D4w). The associations between survivin mRNA expression in blood and tumor response to treatment, time to progression (TTP), and overall survival (OS) were analyzed. Blood survivin mRNA levels at D0 and D4w were significantly higher in patients with progressive disease than in those with partial response and stable disease. The detections of blood survivin mRNA positivity at D0 and D4w were associated with unfavorable response to EGFR-TKIs treatment and shorter TTP and OS. Multivariate Cox analysis showed that blood survivin mRNA positivity before and 4 weeks after EGFR-TKIs treatment were independent predictor for worse TTP and OS. In conclusion, Blood survivin mRNA positivity was strongly related to a poor treatment outcome of EGFR-TKIs and may be a potential non-invasive biomarker for NSCLC treatment.

LUNX mRNA-positive cells at different time points predict prognosis in patients with surgically resected nonsmall cell lung cancer

LUNX is a lung-specific gene whose messenger ribonucleic acid (mRNA) expression is strictly limited to normal lung tissue and nonsmall cell lung cancer (NSCLC) tissue. The aim of this study was to investigate whether the detection of LUNX mRNA-positive circulating tumor cells (CTC)s in peripheral blood at different time points is useful for predicting disease recurrence, disease-free survival (DFS), and overall survival (OS) in NSCLC patients undergoing surgery. Serial blood samples from 68 patients with stage I-IIIA NSCLC were examined by real-time quantitative polymerase chain reaction assay targeting LUNX mRNA before (T0) and after surgery (T1) and after the completion of adjuvant chemotherapy (T2). Results showed that LUNX mRNA-positive CTCs were detected in 40 of 68 NSCLC patients (58.8%) before surgery; the detection rates of LUNX mRNA-positive CTCs at T1 and T2 time points were 32.4% (22/68) and 33.3% (20/60), respectively. The detection of LUNX mRNA-positive CTC at 3 time points was associated with lymph node status and pathologic stage. During the follow-up period, patients with LUXN mRNA-positive CTC at 3 time points had a higher relapse rate and a shorter DFS and OS than those without. Multivariate analysis revealed that presence of LUNX mRNA-positive CTC at T1 and T2 time points was an independent unfavorable factor for DFS and OS. In conclusion, detection of LUNX mRNA-positive CTC after surgery and the completion of adjuvant chemotherapy in patients with stage I-IIIA NSCLC are highly predictive for DFS and OS. This technique could aid in the prediction of prognosis and design of tailored treatment.

Survivin and Smac gene expressions but not livin are predictors of prognosis in non-small cell lung cancer patients treated with adjuvant chemotherapy following surgery

OBJECTIVE

Survivin and livin, which are members of the inhibitor of apoptosis protein family, regulate both programmed cell death and proliferation. Second mitochondria-derived activator of caspase is thought to regulate apoptosis by antagonizing inhibitor of apoptosis protein. These gene expressions are regarded as prognostic markers in some malignancies. However, result in previous studies of the association of these gene expressions with prognosis of patients with non-small cell lung cancer remains contradictory.

METHODS

Survivin, livin and second mitochondria-derived activator of caspase mRNA was detected by semi-quantitative reverse transcriptase-polymerase chain reaction in surgical resected tumor specimen from 66 non-small cell lung patients who received adjuvant platinum-based chemotherapy.

RESULTS

Results showed that patients with survivin high expression had significantly shorter tumor-free survival (P = 0.012) and overall survival (P = 0.007) than those with survivin low expression. There was a significant association of second mitochondria-derived activator of caspase high expression in non-small cell lung cancer tissue with longer tumor-free survival (P = 0.021) and overall survival (P = 0.0013). However, livin mRNA expression level had no impact on the tumor-free survival and overall survival of the patients. In multivariate analyses, survivin mRNA high expression (P = 0.033 and P = 0.024) and advanced pathologic stage (P = 0.009 and P = 0.008) were the factors which independently predicted a worse tumor-free survival and overall survival.

CONCLUSIONS

Our data suggest that assessment of survivin and second mitochondria-derived activator of caspase mRNA expression may be useful for predicting survival in non-small cell lung cancer patients receiving platinum-based chemotherapy after surgical resection and can provide valuable information for deciding better therapy strategy.

Dichlorodiphenyltrichloroethane usage in the former Soviet Union

DDT (Dichlorodiphenyltrichloroethane), an organochlorine pesticide (OCP), is one of 12 persistent organic pollutants (POPs) that is being proposed for elimination or control under the Stockholm Convention on POPs. This paper presents historical DDT usage in the Former Soviet Union (FSU) from different sources. Although the data from different sources do not agree with each other, the data clearly show that the usage of DDT in the FSU were intensive in the 1950s and 1960s, and the use of DDT continued until early 1990s although DDT was officially banned in 1969/1970 by the FSU government. Two estimations (high and low) are made for the historical annual DDT usage in the FSU. The total DDT usage in the FSU from 1946 and 1990 was 520 kt for the high estimation and 250 kt for the low estimation. Gridded DDT usage inventories in the FSU on a 1 degree longitude by 1 degree latitude grid system are created by using the gridded distribution of cropland density for the FSU, and show that DDT usage varied considerably across the FSU. Most DDT was applied in southern regions of the FSU where agricultural activity was greatest, such as in Moldova and Ukraine followed by the Northern Caucasus region of Russia and the Central Asian republics.