Sine oculis homeobox homolog 1 promotes α5ß1-mediated invasive migration and metastasis of cervical cancer cells.

Sine oculis homeobox homolog 1 (SIX1) has been supposed to be correlated with the metastasis and poor prognosis of several malignancies. However, the effect of SIX1 on the metastatic phenotype of tumor cells and the underlying mechanisms were still unclear to date. Here we report that SIX1 can promote α5ß1-mediated metastatic capability of cervical cancer cells. SIX1 promoted the expression of α5ß1 integrin to enhance the adhesion capacity of tumor cells in vitro and tumor cell arrest in circulation in vivo. Moreover, higher expression of SIX1 in tumor cells resulted in the increased production of active MMP-2 and MMP-9, up-regulation of anti-apoptotic genes (BCL-XL and BCL2) and down-regulation of pro-apoptotic genes (BIM and BAX), thus promoting the invasive migration and anoikis-resistance of tumor cells. Importantly, blocking α5ß1 abrogated the regulatory effect of SIX1 on the expression of these genes, and also abolished the promotional effect of SIX1 on invasive capability of tumor cells. Furthermore, knock-down of α5 could abolish the promoting effect of SIX1 on the development of metastatic lesions in both experimental and spontaneous metastasis model. Therefore, by up-regulating α5ß1 expression, SIX1 not only promoted the adhesion capacity, but also augmented ECM-α5ß1-mediated regulation of gene expression to enhance the metastatic potential of cervical cancer cells. These results suggest that SIX1/α5ß1 might be considered as valuable marker for metastatic potential of cervical cancer cells, or a therapeutic target in cervical cancer treatment.

Genetic Analysis of Two Novel GPI Variants Disrupting H Bonds and Localization Characteristics of 55 Gene Variants Associated with Glucose-6-phosphate Isomerase Deficiency.

OBJECTIVE: Glucose-6-phosphate isomerase (GPI) deficiency is a rare hereditary nonspherocytic hemolytic anemia caused by GPI gene variants. This disorder exhibits wide heterogeneity in its clinical manifestations and molecular characteristics, often posing challenges for precise diagnoses using conventional methods. To this end, this study aimed to identify the novel variants responsible for GPI deficiency in a Chinese family. METHODS: The clinical manifestations of the patient were summarized and analyzed for GPI deficiency phenotype diagnosis. Novel compound heterozygous variants of the GPI gene, c.174C>A (p.Asn58Lys) and c.1538G>T (p.Trp513Leu), were identified using whole-exome and Sanger sequencing. The AlphaFold program and Chimera software were used to analyze the effects of compound heterozygous variants on GPI structure. RESULTS: By characterizing 53 GPI missense/nonsense variants from previous literature and two novel missense variants identified in this study, we found that most variants were located in exons 3, 4, 12, and 18, with a few localized in exons 8, 9, and 14. This study identified novel compound heterozygous variants associated with GPI deficiency. These pathogenic variants disrupt hydrogen bonds formed by highly conserved GPI amino acids. CONCLUSION: Early family-based sequencing analyses, especially for patients with congenital anemia, can help increase diagnostic accuracy for GPI deficiency, improve child healthcare, and enable genetic counseling.

Case report: Genetic analysis of a novel intronic inversion variant in the SPTB gene associated with hereditary spherocytosis.

Background: Hereditary spherocytosis (HS) is a congenital haemolytic anaemia attributed to dysregulation or abnormal quantities of erythrocyte membrane proteins. Currently, the most common erythrocytic gene, spectrin ß (SPTB), variants are located in exons and give rise to mRNA defects. However, the genetic characteristics and pathogenic mechanisms of SPTB intronic variants are not completely understood. This study aimed to analyse a rare intronic inversion variant in the SPTB gene associated with HS, and explore the impact of the variant on SPTB mRNA splicing. Method: The clinical manifestations of the patient were summarised and analysed for spherocytosis phenotype diagnosis. The pathogenic variant was identified in the proband using targeted next-generation and Sanger sequencing. RNA sequencing was performed to analyse whether SPTB gene splicing and expression were affected. Results: Targeted next-generation sequencing identified a novel disease-associated intronic inversion variant of the SPTB gene in the proband. The inversion variant was located between intron 19 and 20, and contained the entire exon 20 and partial sequences of adjacent introns. Sanger sequencing confirmed that the intronic inversion variant only appeared in the genome of the proband, not in his parents. RNA sequencing revealed that the variant could result in the skipping of exon 20 and reduced expression of SPTB mRNA. Conclusion: This study identifies a rare intronic inversion variant in the SPTB gene associated with hereditary spherocytosis. The pathogenic variant can lead to exon 20 skipping and decreased SPTB gene expression. This finding has not been previously reported in any literature. This study can expand the intronic variant spectrum of the SPTB gene, deepen our understanding of HS pathogenesis, and contribute to the genetic diagnosis and clinical management of patients.

Case Report: Is Surgical Treatment Beneficial for Intracranial Basal Ganglia Cunninghamellamycosis Following Haematopoietic Stem Cell Transplantation?

Cunninghamellamycosis is an unusual but often highly fatal mucormycosis caused by Cunninghamella bertholletiae, which belongs to the basal lineage order Mucorales. It is especially fatal when the central nervous system is involved. So far, there are few reported cases of surgical treatment for intracranial mucormycosis in children after allogeneic haematopoietic stem cell transplantation (HSCT). The surgical management of deep-seated basal ganglia fungal lesions remains controversial, and its clinical benefits are not yet well established. Herein, we present a rare case of disseminated mucormycosis caused by C. bertholletiae involving the lung and intracranial basal ganglia after homologous leucocytic antigen-matched sibling donor HSCT. The patient was successfully treated for intracranial cunninghamellamycosis with neuroendoscopic surgery and systemic wide-spectrum antifungal treatment and achieved pulmonary recovery without recurrent C. bertholletiae infection or neurologic sequelae. Over the follow-up period of 13 months, there were no adverse events associated with the intracranial surgical debridement, and the patient remained in good health.

Application of Next-Generation Sequencing in Infections After Allogeneic Haematopoietic Stem Cell Transplantation: A Retrospective Study.

This retrospective study aimed to determine the characteristics of infection and diagnostic efficacy of next-generation sequencing (NGS) in patients with fever after allogeneic hematopoietic stem cell transplantation (allo-HSCT). A total of 71 patients with fever after HSCT were enrolled in this study. Compared with conventional microbiological test (CMT), we found that the sensitivity of NGS versus CMT in peripheral blood samples was 91.2% vs. 41.2%, and that NGS required significantly less time to identify the pathogens in both monomicrobial infections (P=0.0185) and polymicrobial infections (P= 0.0027). The diagnostic performance of NGS was not affected by immunosuppressant use. Viruses are the most common pathogens associated with infections. These results indicated that the sensitivity, timeliness, and clinical significance of NGS are superior for the detection of infections. Although NGS has the advantage of identifying a wide range of potential pathogens, the positive rate is related closely to the sample type. Therefore, we recommend that, in the clinical application of NGS to detect pathogens in patients after allo-HSCT, an appropriate sample type and time should be selected and submitted to improve the positive rate and accuracy of NGS. NGS holds promise as a powerful technology for the diagnosis of fever after HSCT.

Mechanisms of Senescence-Related NKG2D Ligands Release and Immune Escape Induced by Chemotherapy in Neuroblastoma Cells.

Chemotherapy-induced senescence promotes immunocyte aggregation in the tumor microenvironment by upregulating the surface expression of activating ligands in cancer cells. However, these senescent tumor cells cannot be completely cleared and can induce tumor recurrence. Previous studiesshowed that soluble natural killer (NK) group 2D (NKG2D) ligands impair the recognition of multiple immune cells. In this study, we established an in vitro senescence model using neuroblastoma cells subjected to low-dose Chemotherapeutic drug doxorubicin or the Aurora A inhibitor MLN8237. The results showed that different neuroblastoma cell lines showed increased secretion of the NKG2D ligand MHC class I polypeptide-related sequence A/B (MICA/B) following proteolysis after treatment, with MICA/B subsequently recruited to exosomes to downregulate NKG2D expression in NK cells. Interestingly, disintegrin and metalloproteinase domain-containing 10 (ADAM10) was upregulated in senescent tumor cells, and combined treatment with the ADAM10 inhibitor GI254023X and chemotherapeutic drugs inhibited MICA/B secretion and enhanced recognition and killing by NK cells. Additionally, we found that expression of the long noncoding RNA MALAT1 was significantly increased in senescent neuroblastoma cells, and that MALAT1 served as a sponge for microRNA (miR)-92a-3p to counteract miR-92a-3p-mediated repression of ADAM10 levels. Furthermore, administration of a MALAT1 inhibitor or an miR-92a-3p mimic reduced the MICA/B shedding and enhanced recognition and killing by NK cells. These results confirmed that low-dose chemotherapy induces senescence in neuroblastoma cells, and that senescent tumor cells promote the shedding of the NKG2D ligand MICA/B through the MALAT1/miR-92a/ADAM10 axis, thereby contributing to the formation of a suppressive immune microenvironment and promoting immune escape.

W-Compound can be used as a Biomarker for Fetal Thyroid Function and a Potential Tool for Screening Congenital Hypothyroidism.

Sulfoconjugation is the major pathway for thyroid hormone (TH) metabolism, converting T4 to inactive metabolites, T4S, rT3S, and T3S in fetus, via sulfotransferases (SULT) and type 3 deiodinase in gestation. Consistent with high production rate of T4S and rT3S, there are high serum sulfated iodothyronine analogs, including T4S, T3S, rT3S, and 3,3'-T2S (T2S), in ovine and human fetal and preterm infants. Fetal TH metabolic pathways predict T2S as the major TH metabolite in the fetus. Since maternal T2S appears to be quantitatively derived from fetal T3 (the active TH), the amount of T2S in the maternal compartment correlates with fetal thyroid function in sheep. In humans, maternal serum contains high levels of radioimmunoassayable T2S; however, it displays as a peak adjacent to but unidentical to synthetic T2S on HLPC and we named it the W-Compound. Levels of W-Compound increase during pregnancy and peak as high as 20-fold to that of nonpregnant women. Maternal serum levels of W-Compound significantly correlate with fetal T4 and W-compound concentrations but not maternal serum T4 in euthyroid or hyperthyroid women, showing a distinct difference between fetal and maternal in TH metabolism. Fetal T2S is actively transferred to the mother via placenta and the quantity of T2S or its metabolite (W-Compound) in maternal compartment reflects fetal thyroid function. Thus, maternal serum W-Compound may be a biomarker for monitoring fetal thyroid function in utero, although more investigations are needed to determine if it can be used as an alternative strategy for screening/managing congenital hypothyroidism due to dysregulated thyroid hormone metabolism.

Successful low-dose chemotherapy for refractory Epstein-Barr virus-related post-transplant lymphoproliferative disorder following hematopoietic stem cell transplantation in a child with Wiskott-Aldrich syndrome.

We report the first case of a 12-year-old boy with Wiskott-Aldrich syndrome who developed CD20-weakly expressed and CD30-highly expressed Epstein-Barr virus-related post-transplant lymphoproliferative disorder refractory to rituximab treatment. The patient was effectively and safely treated with personalized low-dose chemotherapy and subsequently remained in complete remission for 1 year.

Advanced glycation end products of DNA: quantification of N2-(1-Carboxyethyl)-2'-deoxyguanosine in biological samples by liquid chromatography electrospray ionization tandem mass spectrometry.

Methylglyoxal (MG) and related alpha-oxoaldehydes react with proteins, lipids, and DNA to give rise to covalent adducts known as advanced glycation end products (AGEs). Elevated levels of AGEs have been implicated in the pathological complications of diabetes, uremia, Alzheimer's disease, and possibly cancer. There is therefore widespread interest in developing sensitive methods for the in vivo measurement of AGEs as prognostic biomarkers and for treatment monitoring. The two diastereomeric MG-DNA adducts of N(2)-(1-carboxyethyl)-2'-deoxyguanosine (CEdG) are the primary glycation products formed in DNA; however, accurate assessment of their distribution in vivo has not been possible since there is no readily available quantitative method for CEdG determination in biological samples. To address these issues, we have developed a sensitive and quantitative liquid chromatography electrospray ionization tandem mass spectrometry assay using the stable isotope dilution method with an (15)N(5)-CEdG standard. Methods for CEdG determination in urine or tissue extracted DNA are described. Changes in urinary CEdG in diabetic rats in response to oral administration of the AGE inhibitor LR-90 are used to demonstrate the potential utility of the method for treatment monitoring. Both stereoisomeric CEdG adducts were detected in a human breast tumor and normal adjacent tissue at levels of 3-12 adducts/10(7) dG, suggesting that this lesion may be widely distributed in vivo. Strategies for dealing with artifactual adduct formation due to oxoaldehyde generation during DNA isolation and enzymatic workup procedures are described.

Phase I trial of intraperitoneal gemcitabine in the treatment of advanced malignancies primarily confined to the peritoneal cavity.

PURPOSE: To determine the maximally tolerated dose, toxicity, and pharmacokinetics of i.p. gemcitabine. EXPERIMENTAL DESIGN: Patients had peritoneal carcinomatosis. Gemcitabine (40, 80, 120, or 160 mg/m(2)) was administered into the peritoneal cavity in 2 L of warmed saline on days 1, 4, 8, and 12 of a 28-day cycle. RESULTS: Thirty patients received 63 (median, 2; range, 0-6) courses. Tumors included ovary (14), uterus (2), colon (6), pancreas (3), and others (5). Dose-limiting toxicity included nausea, vomiting, diarrhea, dyspnea, fatal respiratory failure, and grade 3 elevation of alanine aminotransferase in three patients. Hematologic toxicity and pain were

C/EBPß enhances platinum resistance of ovarian cancer cells by reprogramming H3K79 methylation.

Chemoresistance is a major unmet clinical obstacle in ovarian cancer treatment. Epigenetics plays a pivotal role in regulating the malignant phenotype, and has the potential in developing therapeutically valuable targets that improve the dismal outcome of this disease. Here we show that a series of transcription factors, including C/EBPß, GCM1, and GATA1, could act as potential modulators of histone methylation in tumor cells. Of note, C/EBPß, an independent prognostic factor for patients with ovarian cancer, mediates an important mechanism through which epigenetic enzyme modifies groups of functionally related genes in a context-dependent manner. By recruiting the methyltransferase DOT1L, C/EBPß can maintain an open chromatin state by H3K79 methylation of multiple drug-resistance genes, thereby augmenting the chemoresistance of tumor cells. Therefore, we propose a new path against cancer epigenetics in which identifying and targeting the key regulators of epigenetics such as C/EBPß may provide more precise therapeutic options in ovarian cancer.

Oblimersen and alpha-interferon in metastatic renal cancer: a phase II study of the California Cancer Consortium.

PURPOSE: Oblimersen is an 18-base oligodeoxynucleotide encoding antisense to the gene for bcl-2, an anti-apoptotic protein that is upregulated in renal and other cancers. This study was designed to evaluate the combination of oblimersen with alpha-Interferon in advanced renal cancer. Trial endpoints were antitumor efficacy and toxicity, pharmacokinetics, and evidence of apoptosis in peripheral blood mononuclear cells. METHODS: Patients with measurable advanced renal cancer and 0-1 prior therapy were eligible. Treatment consisted of oblimersen, 7 mg/kg/day, as a continuous intravenous infusion 7 days of every 14 day cycle, plus alpha-IFN, 5 million units/m(2) subcutaneously, days 4 and 6 of the first oblimersen infusion, then thrice weekly. Blood for laboratory correlates was collected before treatment, during oblimersen, and during therapy with both agents. RESULTS: Twenty-three patients were enrolled, five of whom had prior systemic therapy (three with prior high-dose interleukin-2). The median number of treatment cycles was 4 (range 1-12). One patient had a partial response lasting 2.5 months. The Grade 3-4 toxicities were fatigue, fever, myelosuppression, hepatic enzyme and metabolic abnormalities. Laboratory analyses of CD3+ lymphocyte apoptotic markers demonstrated no change between pre-treatment and on-treatment levels of bcl-2 or Annexin/PI positivity by flow cytometry. Mean oblimersen steady-state plasma concentration and clearance was 2.3 +/- 0.9 microg/ml and 0.15 +/- 0.07 l/h/kg, respectively. CONCLUSIONS: Oblimersen given in this dose and schedule with alpha-IFN does not appear sufficiently active to warrant further study in advanced renal cancer. Combinations with newer targeted agents may show greater promise.

Prognostic and therapeutic value of disruptor of telomeric silencing-1-like (DOT1L) expression in patients with ovarian cancer.

BACKGROUND: Epigenetics has been known to play a critical role in regulating the malignant phenotype. This study was designed to examine the expression of DOT1L (histone 3 lysine 79 methyltransferase) and H3K79 methylation in normal ovarian tissues and ovarian tumors and to explore the function of DOT1L and its underline mechanisms in ovarian cancer. METHODS: The expression of DOT1L and H3K79 methylation in 250 ovarian tumor samples and 24 normal ovarian samples was assessed by immunohistochemistry. The effects of DOT1L on cell proliferation in vitro were evaluated using CCK8, colony formation and flow cytometry. The DOT1L-targeted genes were determined using chromatin immune-precipitation coupled with high-throughput sequencing (ChIP-seq) and ChIP-PCR. Gene expression levels were measured by real-time PCR and immunoblotting. The effects of DOT1L on tumor growth in vivo were evaluated using an orthotopic ovarian tumor model. RESULTS: DOT1L expression and H3K79 methylation was significantly increased in malignant ovarian tumors. High DOT1L expression was associated with International Federation of Gynecology and Obstetrics (FIGO) stage, histologic grade, and lymphatic metastasis. DOT1L was an independent prognostic factor for the overall survival (OS) and progression-free survival (PFS) of ovarian cancer, and higher DOT1L expression was associated with poorer OS and PFS. Furthermore, DOT1L regulates the transcription of G1 phase genes CDK6 and CCND3 through H3K79 dimethylation; therefore, blocking DOT1L could result in G1 arrest and thereby impede the cell proliferation in vitro and tumor growth in vivo. CONCLUSIONS: Our findings first demonstrate that DOT1L over-expression has important clinical significance in ovarian cancer and also clarify that it drives cell cycle progression through transcriptional regulation of CDK6 and CCND3 through H3K79 methylation, suggesting that DOT1L might be potential target for prognostic assessment and therapeutic intervention in ovarian cancer.

In vitro characterization of enzymatic properties and inhibition of the p53R2 subunit of human ribonucleotide reductase.

p53R2 is a newly identified subunit of ribonucleotide reductase (RR) and plays a crucial role in supplying precursors for DNA repair in a p53-dependent manner. In our current work, all three human RR subunit proteins (p53R2, hRRM2, and hRRM1) were prokaryotically expressed and highly purified. Using an in vitro [(3)H]CDP reduction assay, the activity of RR reconstituted with either p53R2 or hRRM2 was found to be time, concentration, and hRRM1 dependent. The kinetic activity of p53R2-containing RR was about 20-50% lower than that of hRRM2-containing RR. Using a synthetic heptapeptide to inhibit RR activity, it was shown that p53R2 bound to hRRM1 through the same COOH-terminal heptapeptide as hRRM2. However, hRRM2 had a 4.76-fold higher binding affinity for hRRM1 than p53R2, which may explain the reduced RR activity of p53R2 relative to hRRM2. Of interest, p53R2 was 158-fold more susceptible to the iron chelator deferoxamine mesylate than hRRM2, although the iron content of the two proteins determined by atomic absorption spectrometer was almost the same. To the contrary, p53R2 was 2.50-fold less sensitive than hRRM2 to the radical scavenger hydroxyurea, whereas EPR showed similar spectra of the tyrosyl radical in two proteins. Triapine, a new RR inhibitor, was equally potent for p53R2 and hRRM2. These inhibition studies showed that the iron center and tyrosyl radical are involved in RR activity for both p53R2 and hRRM2. The susceptibility differences to RR inhibitors between p53R2 and hRRM2 may lead to a new direction in drug design for human cancer treatment.

A dityrosyl-diiron radical cofactor center is essential for human ribonucleotide reductases.

Ribonucleotide reductase catalyzes the reduction of ribonucleotides to deoxyribonucleotides for DNA biosynthesis. A tyrosine residue in the small subunit of class I ribonucleotide reductase harbors a stable radical, which plays a central role in the catalysis process. We have discovered that an additional tyrosine residue, conserved in human small subunits hRRM2 and p53R2, is required for the radical formation and enzyme activity. Mutations of this newly identified tyrosine residue obliterated the stable radical and the enzymatic activity of human ribonucleotide reductases shown by electron paramagnetic resonance spectroscopy and enzyme activity assays. Three-dimensional structural analysis reveals for the first time that these two tyrosines are located at opposite sides of the diiron cluster. We conclude that both tyrosines are necessary in maintaining the diiron cluster of the enzymes, suggesting that the assembly of a dityrosyl-diiron radical cofactor center in human ribonucleotide reductases is essential for enzyme catalytic activity. These results should provide insights to design better ribonucleotide reductase inhibitors for cancer therapy.

SIX1 coordinates with TGFß signals to induce epithelial-mesenchymal transition in cervical cancer.

Epithelial-mesenchymal transition (EMT) plays a critical role in promoting tumor invasion and metastasis. However, the key cofactors that modulate the signal transduction to induce EMT have note been fully explored to date. The present study reports that sine oculis homeobox homolog 1 (SIX1) is able to promote EMT of cervical cancer by coordinating with transforming growth factor (TGF)ß-SMAD signals. The expression of SIX1 was negatively correlated with the expression of the epithelial marker E-cadherin in two independent groups of cervical cancer specimens. SIX1 could promote the transition of mesenchymal phenotype in the presence of active TGFß signals in vitro and in vivo. TGFß-SMAD signals were required for the SIX1-mediated promotion of EMT and metastatic capacity of cervical cancer cells. Together, SIX1 and TGFß cooperated to induce more remarkable changes in the transition of phenotype than each of them alone, and coordinated to promote cell motility and tumor metastasis in cervical cancer. These results suggest that the coordination of SIX1 and TGFß signals may be crucial in the EMT program, and that SIX1/TGFß may be considered a valuable marker for evaluating the metastatic potential of cervical cancer cells, or a therapeutic target in the treatment of cervical cancer.

Renoprotective and lipid-lowering effects of LR compounds, novel advanced glycation end product inhibitors, in streptozotocin-induced diabetic rats.

The accelerated formation of advanced glycation/lipoxidation end products (AGEs/ALEs) has been implicated in the pathogenesis of various diabetic complications. Several natural and synthetic compounds have been proposed and advanced as inhibitors of AGE/ALE formation. We examined the effects of two new AGE/ALE inhibitors, LR-9 and LR-74, on the prevention of early renal disease and dyslipidemia in streptozotocin (STZ)-induced diabetic rats. Diabetic rats were treated with either LR-9 or LR-74 for 32 weeks. Progression of renal disease was evaluated by measurements of urinary albumin and plasma creatinine concentrations. AGE-induced chemical modification of the tail tendon collagen and levels of Nepsilon-(carboxymethyl)- and (carboxyethyl)- lysines (CML and CEL) in skin collagen were measured. AGE/ALE levels in kidneys were determined by immunohistochemistry. Plasma lipids and their lipid hydroperoxide concentrations were also determined. Treatment of either LR-9 or LR-74 significantly inhibited the increase in albuminuria, plasma creatinine, hyperlipidemia, and plasma lipid peroxidation in diabetic rats without any effects on hyperglycemia. Both compounds also reduced CML-AGE accumulation in kidney glomeruli and tubules, AGE-linked fluorescence and cross-linking of tail collagen, and levels of CML and CEL in skin collagen. These results suggest that both LR compounds can inhibit the progression of renal disease and also prevent dyslipidemia in experimental diabetes. These compounds may have an additional beneficial effect as an antioxidant against lipid peroxidation, and thus may provide alternative therapeutic options for the treatment of various diabetic macrovascular complications.

Pharmacodynamics (PD) and pharmacokinetics (PK) of E7389 (eribulin, halichondrin B analog) during a phase I trial in patients with advanced solid tumors: a California Cancer Consortium trial.

BACKGROUND: The California Cancer Consortium completed a phase I trial of E7389 (eribulin mesylate), an analog of the marine natural product halichondrin B. This trial was to determine the pharmacodynamics, pharmacokinetics, and MTD of E7389 administered by bolus injection weekly for 3 weeks out of four. METHODS: This trial included a rapid titration design. Real-time pharmacokinetics were utilized to guide dose escalation. Initially, single-patient cohorts were enrolled with intra- and inter-patient dose doubling. The second phase was a standard 3 + 3 dose escalation schedule. At the MTD, a cohort of patients was enrolled for target validation studies (separate manuscript). The starting dose was 0.125 mg/m(2), and doses were doubled within and between patients in the first phase. Blood and urine sampling for E7389 pharmacokinetics was performed on doses 1 and 3 of cycle 1. Levels were determined using a LC/MS/MS assay. RESULTS: Forty patients were entered. Thirty-eight were evaluable for toxicity and 35 for response. The rapid escalation ended with a grade 3 elevation of alkaline phosphatase at 0.5 mg/m(2)/week. The second phase ended at 2.0 mg/m(2)/week with dose-limiting toxicities of grades 3 and 4 febrile neutropenia. Other toxicities included hypoglycemia, hypophosphatemia, and fatigue. The MTD was 1.4 mg/m(2)/week. Responses included four partial responses (lung cancer [2], urothelial [1], and melanoma [1]). CONCLUSIONS: E7389 was well tolerated in this trial with the major toxicity being myelosuppression. PD shows that E7389 induces significant morphologic changes (bundle formation) in the microtubules of peripheral blood mononuclear cells and tumor cells in vivo. The data suggest that lower intra-tumoral levels of ß-tubulin III or higher intra-tumoral levels of MAP4 may correlate with response to E7389, while lower intra-tumoral levels of stathmin may be associated with progression. PK data reveal that E7389 exhibits a tri-exponential elimination from the plasma of patients receiving a rapid i.v. infusion. At sub-toxic doses, plasma concentrations of E7389 are maintained well above the levels required for activity in vitro for >72 h.

Sine oculis homeobox homolog 1 promotes DNA replication and cell proliferation in cervical cancer.

Malignant proliferation is the fundamental trait of tumor cells. The initiation of DNA replication represents a key process for cell proliferation, and has a marked impact on tumorigenesis and progression. Here we report that Sine oculis homeobox homolog 1 (SIX1) functions as a master regulator in DNA replication of cervical cancer cells. The expression of SIX1 was induced by the E7 oncoprotein of human papillomaviruses in cervical intraepithelial neoplasia and cervical cancer. The increase of SIX1 expression resulted in the upregulation of multiple genes related to the initiation of DNA replication, including the genes coding for the proteins in minichromosome maintenance complex (MCM2, MCM3, MCM6), DNA polymerase α-primase complex (POLA1, PRIM1, PRIM2), clamp loader (RFC3, RFC4, RFC5), DNA polymerase δ complex (POLD3) and DNA polymerase ε complex (POLE2). In line with this, the increase of SIX1 expression enhanced DNA synthesis, accelerated G1 to S phase progression, and promoted the proliferation of cervical cancer cells and the growth of cervical cancer. Consistently, knockdown of SIX1 could hamper DNA synthesis, slow down G1 to S phase progression, and suppress tumor cell proliferation and tumor growth. Importantly, SIX1 could more efficiently promote anchorage-independent cell growth. These results suggest that the increase of SIX1 expression could promote tumorigenesis, progression and invasive growth of cervical cancer by promoting DNA replication, and that targeting SIX1 may have significant therapeutic value in cervical cancer treatment.

SIX1 promotes tumor lymphangiogenesis by coordinating TGFß signals that increase expression of VEGF-C.

Lymphatic vessels are one of the major routes for the dissemination of cancer cells. Malignant tumors release growth factors such as VEGF-C to induce lymphangiogenesis, thereby promoting lymph node metastasis. Here, we report that sine oculis homeobox homolog 1 (SIX1), expressed in tumor cells, can promote tumor lymphangiogenesis and lymph node metastasis by coordinating with TGFß to increase the expression of VEGF-C. Lymphangiogenesis and lymph node metastasis in cervical cancer were closely correlated with higher expression of SIX1 in tumor cells. By enhancing VEGF-C expression in tumor cells, SIX1 could augment the promoting effect of tumor cells on the migration and tube formation of lymphatic endothelial cells (LEC) in vitro and lymphangiogenesis in vivo. SIX1 enhanced TGFß-induced activation of SMAD2/3 and coordinated with the SMAD pathway to modulate VEGF-C expression. Together, SIX1 and TGFß induced much higher expression of VEGF-C in tumor cells than each of them alone. Despite its effect in promoting VEGF-C expression, TGFß could inhibit lymphangiogenesis by directly inhibiting tube formation by LECs. However, the increased production of VEGF-C not only directly promoted migration and tube formation of LECs but also thwarted the inhibitory effect of TGFß on LECs. That is, tumor cells that expressed high levels of SIX1 could promote lymphangiogenesis and counteract the negative effects of TGFß on lymphangiogenesis by increasing the expression of VEGF-C. These findings provide new insights into tumor lymphangiogenesis and the various roles of TGFß signaling in tumor regulation. Our results also suggest that SIX1/TGFß might be a potential therapeutic target for preventing lymph node metastasis of tumor.