Matrix metalloproteinases as attractive therapeutic targets for chronic pain: A narrative review

Chronic pain constitutes an abnormal pain state that detrimentally affects the quality of life, daily activities, occupational performance, and stability of mood. Despite the prevalence of chronic pain, effective drugs with potent abirritation and minimal side effects remain elusive. Substantial studies have revealed aberrant activation of the matrix metalloproteinases (MMPs) in multiple chronic pain models. Additionally, emerging evidence has demonstrated that the downregulation of MMPs can alleviate chronic pain in diverse animal models, underscoring the unique and crucial role of MMPs in different stages and types of chronic pain. This review delves into the mechanistic insights and roles of MMPs in modulating chronic pain. The aberrant activation of MMPs has been linked to neuropathic pain through mechanisms involving myelin abnormalities in peripheral nerve and spinal dorsal horn (SDH), hyperexcitability of dorsal root ganglion (DRG) neurons, activation of N-methyl-d-aspartate receptors (NMDAR) and Ca2+-dependent signals, glial cell activation, and proinflammatory cytokines release. Different MMPs also contribute significantly to inflammatory pain and cancer pain. Furthermore, we summarized the substantial therapeutic potential of MMP pharmacological inhibitors across different types of chronic pain. Overall, our findings underscore the promising therapeutic prospects of MMPs targeting for managing chronic pain.

Targeting the JAK2/STAT3 signaling pathway for chronic pain

Chronic pain is a notable health concern because of its prevalence, persistence, and associated mental stress. Drugs targeting chronic pain with potent abirritation, and minimal side effects remain unidentified. Substantial evidence indicates that the Janus Kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway plays a distinct and critical role in different stages of chronic pain. Aberrant activation of the JAK2/STAT3 signaling pathway is evident in multiple chronic pain models. Moreover, an increasing number of studies have demonstrated that the downregulation of JAK2/STAT3 can attenuate chronic pain in different animal models. In this review, we investigated the mechanism and role of the JAK2/STAT3 signaling pathway in modulating chronic pain. The aberrant activation of JAK2/STAT3 can trigger chronic pain by interacting with microglia and astrocytes, releasing proinflammatory cytokines, inhibiting anti-inflammatory cytokines, and regulating synaptic plasticity. We also retrospectively reviewed current reports on JAK2/STAT3 pharmacological inhibitors that demonstrated their significant therapeutic potential in different types of chronic pain. In summary, our results provide strong evidence that the JAK2/STAT3 signaling pathway is a promising therapeutic target for chronic pain.

Interleukin-17: A Putative Novel Pharmacological Target for Pathological Pain

Pathological pain imposes a huge burden on the economy and the lives of patients. At present, drugs used for the treatment of pathological pain have only modest efficacy and are also plagued by adverse effects and risk for misuse and abuse. Therefore, understanding the mechanisms of pathological pain is essential for the development of novel analgesics. Several lines of evidence indicate that interleukin-17 (IL-17) is upregulated in rodent models of pathological pain in the periphery and central nervous system. Besides, the administration of IL-17 antibody alleviated pathological pain. Moreover, IL-17 administration led to mechanical allodynia which was alleviated by the IL-17 antibody. In this review, we summarized and discussed the therapeutic potential of targeting IL-17 for pathological pain. The upregulation of IL-17 promoted the development of pathological pain by promoting neuroinflammation, enhancing the excitability of dorsal root ganglion neurons, and promoting the communication of glial cells and neurons in the spinal cord. In general, the existing research shows that IL-17 is an attractive therapeutic target for pathologic pain, but the underlying mechanisms still need to be investigated.

Inhibition of Brd4 alleviates osteoarthritis pain via suppression of neuroinflammation and activation of Nrf2-mediated antioxidant signalling

BACKGROUND AND PURPOSE

Osteoarthritis (OA) pain remains a major clinical problem. It is urgent to identify novel therapeutic approaches for OA pain states. Bromodomain and extra-terminal (BET) protein inhibitors have robust anti-inflammatory effects in several pain models. However, the underlying mechanisms of these inhibitors in OA pain have not been determined. We, therefore, investigated the effects and the underlying mechanism(s) of BET inhibition on pain-related behaviours in a rat model of OA.

EXPERIMENTAL APPROACH

The OA model was established by intra-articular injection of monosodium iodoacetate (MIA) in rat knees. Pain behaviours were assessed in rats by hindlimb weight-bearing asymmetry, mechanical allodynia and thermal hyperalgesia. Possible mechanisms underlying BET inhibition were explored in the MIA-induced OA pain model in the spinal cord and dorsal root ganglia (DRG).

KEY RESULTS

Inhibiting bromodomain-containing protein 4 (Brd4) with either JQ1 or MS417, or using AAV2/9-shRNA-Brd4-EGFP-mediated knockdown of Brd4 genes, significantly attenuated MIA-induced pain behaviours. Brd4 inhibition suppressed NF-κB and NF-κB-mediated inflammatory cytokines in both the spinal cord and DRG in rats with MIA-induced OA pain. Brd4 inhibition also attenuated the oxidative stress and promoted nuclear factor erythroid-2-related factor 2 (Nrf2)-dependent antioxidant genes in both the spinal cord and DRG in our odel of MIA-induced OA pain.

CONCLUSIONS AND IMPLICATIONS

In conclusion, Brd4 inhibition alleviated MIA-induced OA pain in rats, via suppression of neuroinflammation and activation of Nrf2-mediated antioxidant signalling. Although our model does not perfectly represent how OA develops in humans, inhibition of Brd4 may provide novel insights into possible treatments for OA pain.

[Three cases of occupational acute trimethyltin chloride poisoning]

Trimethyltin chloride is a highly toxic substance, which is absorbed through respiratory tract, skin and digestive tract, with central nervous system injury as the main clinical manifestations, and can be accompanied by damage to various organs. In this paper, the treatment process of 3 patients with acute trimethyltin chloride poisoning was reviewed, and their clinical manifestations, auxiliary examination, diagnosis and treatment were analyzed. Three patients were misdiagnosed as mental abnormality, encephalitis, and hepatic encephalopathy in different hospitals in the early stage of medical treatment, suggesting that clinicians should pay attention to the occupational contact history of poisoned patients and conduct toxicant detection in time to avoid misdiagnosis and mistreatment.

STING/NF-κB/IL-6-Mediated Inflammation in Microglia Contributes to Spared Nerve Injury (SNI)-Induced Pain Initiation

Innate immune response acts as the first line of host defense against damage and is initiated following the recognition of pathogen-associated molecular patterns (PAMPs). For double-stranded DNA (dsDNA) sensing, interferon gene stimulator (STING) was discovered to be an integral sensor and could mediate the immune and inflammatory response. Selective STING antagonist C-176 was administered and pain behaviors were assessed following spared nerve injury (SNI)-induced neuropathic pain. The level of serum dsDNA following neuropathic pain was assessed using Elisa analysis. STING signaling pathway, microglia activation, and proinflammatory cytokines were assessed by qPCR, western blots, Elisa, and immunofluorescence staining. STING agonist DMXAA was introduced into BV-2 cells to assess the inflammatory response in microglial cells. dsDNA was significantly increased following SNI and STING/TANK-binding kinase 1 (TBK1)/nuclear factor-kappa B (NF-κB) pathway was activated in vivo and vitro. Early but not the late intrathecal injection of C-176 attenuated SNI-induced pain hypersensitivity, microglia activation, proinflammatory factors, and phosphorylated JAK2/STAT3 in the spinal cord dorsal horn, and the analgesic effect of C-176 was greatly abolished by recombinant IL-6 following SNI. We provided evidence clarifying dsDNA mediated activation of microglia STING signaling pathway, after which promoting expression of proinflammatory cytokines that are required for hyperalgesia initiation in the spinal cord dorsal horn of SNI model. Further analysis showed that microglial STING/TBK1/NF-κB may contribute to pain initiation via IL-6 signaling. Pharmacological blockade of STING may be a promising target in the treatment of initiation of neuropathic pain.

Targeting the nitric oxide/cGMP signaling pathway to treat chronic pain

Nitric oxide (NO)/cyclic guanosine 3',5'-monophosphate (cGMP) signaling has been shown to act as a mediator involved in pain transmission and processing. In this review, we summarize and discuss the mechanisms of the NO/cGMP signaling pathway involved in chronic pain, including neuropathic pain, bone cancer pain, inflammatory pain, and morphine tolerance. The main process in the NO/cGMP signaling pathway in cells involves NO activating soluble guanylate cyclase, which leads to subsequent production of cGMP. cGMP then activates cGMP-dependent protein kinase (PKG), resulting in the activation of multiple targets such as the opening of ATP-sensitive K⁺ channels. The activation of NO/cGMP signaling in the spinal cord evidently induces upregulation of downstream molecules, as well as reactive astrogliosis and microglial polarization which participate in the process of chronic pain. In dorsal root ganglion neurons, natriuretic peptide binds to particulate guanylyl cyclase, generating and further activating the cGMP/PKG pathway, and it also contributes to the development of chronic pain. Upregulation of multiple receptors is involved in activation of the NO/cGMP signaling pathway in various pain models. Notably the NO/cGMP signaling pathway induces expression of downstream effectors, exerting both algesic and analgesic effects in neuropathic pain and inflammatory pain. These findings suggest that activation of NO/cGMP signaling plays a constituent role in the development of chronic pain, and this signaling pathway with dual effects is an interesting and promising target for chronic pain therapy.

Dimethyl Fumarate Attenuates Pain Behaviors in Osteoarthritis Rats via Induction of Nrf2-Mediated Mitochondrial Biogenesis

AIMS

Osteoarthritis (OA), a chronic degenerative disease, leads to pain and loss of function. Existing treatments for OA pain have limited efficacy and show significant side effects. Dimethyl fumarate, a robust nuclear factor erythroid 2-related factor 2 (Nrf2) activator, could alleviate pain behaviors in chronic pain. This study aims to investigate the role of dimethyl fumarate in a rat model of OA and its underlying mechanisms.

METHODS

We used von Frey filaments to assess the mechanical allodynia. Weight-bearing apparatus was employed to assess the hindlimb weight distribution. Western blot was employed to investigate the protein expressions of mitochondrial biogenesis markers. RT-qPCR was employed to examine the copy number of mitochondrial DNA (mtDNA).

RESULTS

Dimethyl fumarate upregulated mechanical paw withdrawal threshold (MIA + Vehicle, 1.6 ± 0.13g [mean ± SEM]; MIA + DMF, 10.5 ± 0.96g; P ＜ 0.0001). Hindlimb weight distribution was alao upregulated by dimethyl fumarate (MIA + Vehicle, 38.17 ± 0.72g; MIA + DMF, 43.59 ± 1.01g; P ＜ 0.01). Besides, activation of Nrf2 remarkably upregulated the protein levels of PGC-1α (MIA + Vehicle, 0.69 ± 0.07; MIA + DMF, 1.08 ± 0.09; P = 0.0037), NRF1 (MIA + Vehicle, 0.69 ± 0.04; MIA + DMF, 1.00 ± 0.11; P = 0.0114), TFAM (MIA + Vehicle, 0.62 ± 0.11; MIA + DMF, 1.02 ± 0.12; P = 0.0147), and the copy number of mtDNA(MIA + Vehicle, 0.52 ± 0.05; MIA + DMF, 3.81 ± 0.21; P ＜ 0.0001) Conclusions: Taken together, these results show that dimethyl fumarate alleviated pain-related behaviors in a rat model of OA through activation of Nrf2-induced mitochondrial biogenesis.

Notch signaling activation contributes to paclitaxel-induced neuropathic pain via activation of A1 astrocytes

Paclitaxel-induced neuropathic pain (PINP) is a progressive and refractory side effect of chemotherapy with few effective treatments at present. It is well-established that astrocytes activation contributes to the development of PINP. Recent reports showed astrocytes can be divided into A1 and A2 phenotypes. However, whether the transformation of astrocytes participates in PINP and the underlying mechanisms remain unknown. As Notch signaling pathway have shown to be involved in neuropathic pain, we aimed to investigate the relationship between Notch signaling pathway and A1 astrocytes in PINP. Herein we found that both A1 astrocytes and Notch signaling were markedly activated in the spinal cord of PINP rats and the downstream molecules of Notch signaling were colocalized with A1 astrocytes. DAPT (an inhibitor of Notch signaling) not only suppressed the mechanical allodynia of PINP rats, but also inhibited the activation of Notch signaling pathway and A1 astrocytes. Furthermore, Jagged1 (a ligand of Notch1 receptors) dose-dependently induced mechanical hyperalgesia in naïve rats and simultaneously led to Notch signaling activation and A1 astrocytes transformation, all of which were inhibited by DAPT. Taken together, these results demonstrate Notch signaling activation contributes to PINP via A1 astrocytes activation, which provides a promising therapeutic target for PINP.

DKK3 ameliorates neuropathic pain via inhibiting ASK-1/JNK/p-38-mediated microglia polarization and neuroinflammation

BACKGROUND

Neuropathic pain is a common and severely disabling state that affects millions of people worldwide. Microglial activation in the spinal cord plays a critical role in the pathogenesis of neuropathic pain. However, the mechanisms underlying spinal microglial activation during neuropathic pain remain incompletely understood. Here, we investigated the role of Dickkopf (DKK) 3 and its interplay with microglial activation in the spinal cord in neuropathic pain.

METHODS

In this study, we investigated the effects of intrathecal injection of recombinant DKK3 (rDKK3) on mechanical allodynia and microglial activation in the spinal cord after spared nerve injury (SNI) in rats by western blot (WB), immunofluorescence (IF), quantitative polymerase chain reaction (qPCR), and enzyme-linked immunosorbent assay (ELISA).

RESULTS

We found that SNI induced a significant decrease in the levels of DKK3, Kremen-1 and Dishevelled-1 (DVL-1) and up-regulated the expression of phosphorylated apoptosis signal-regulating kinase 1 (p-ASK1), phosphorylated c-JUN N-terminal kinase (p-JNK), phosphorylated p38 (p-p38) in the spinal cord. Moreover, our results showed that exogenous intrathecal administration of rDKK3 inhibited expression of p-ASK1, p-JNK, p-p38, promoted the transformation of microglia from M1 type to M2 type, and decreased the production of pro-inflammatory cytokines compared to the rats of SNI + Vehicle. However, these effects were reversed by intrathecal administration of Kremen-1 siRNA or Dishevelled-1 (DVL-1) siRNA.

CONCLUSIONS

These results suggest that DKK3 ameliorates neuropathic pain via inhibiting ASK-1/JNK/p-38-mediated microglia polarization and neuroinflammation, at least partly, by the Kremen-1 and DVL-1 pathways.

Adipocytokines: Emerging therapeutic targets for pain management

Although pain has lower mortality rates than cancer, diabetes and stroke, pain is a predominate source of distress and disability. However, the management of pain remains an enormous problem. Many drugs used to pain treatment have more or less side effects. Therefore, the development of novel therapeutic target is critical for the treatment of pain. Notably, studies have shown that adipocytokines have a dual role in pain. Growing shreds of evidence shows that the levels of adipocytokines are upregulated or downregulated in the development of pain. In addition, substantial evidence indicates that regulation of adipocytokines levels in models of pain attenuates or promotes pain behaviors. In this review, we summarized and discussed the effect of adipocytokines in pain. These evidence indicates that adipocytokines attenuate or promote pain behaviors through interacting with their receptors, activating serotonin pathway, interacting with μ-opioid receptor, activating microglia, infiltrating macrophage and so on. Overall, adipocytokines have some potential in treating pain, but the underlying mechanisms remain unclear and need to be further studied.

5-HT1F Receptor Agonist Ameliorates Mechanical Allodynia in Neuropathic Pain via Induction of Mitochondrial Biogenesis and Suppression of Neuroinflammation

Neuropathic pain is a devastating disease that affects millions of people worldwide. Serotonin (5-hydroxytryptamine, 5-HT) is involved in pain modulation. Several lines of evidence have indicated that 5-HT1F receptor agonists are potent inducers of mitochondrial biogenesis. In this study, we tested the hypothesis that 5-HT1F receptor agonists ameliorate mechanical allodynia in neuropathic pain via the induction of mitochondrial biogenesis and suppression of neuroinflammation. Male Sprague–Dawley rats were used to establish a neuropathic pain model via spared nerve injury (SNI). The paw withdrawal threshold (PWT) was used to evaluate mechanical allodynia. Real-time polymerase chain reaction was used to examine the mitochondrial DNA (mtDNA) copy number. Western blotting and immunofluorescence were used to examine the expression of target proteins. Our results showed that mitochondrial biogenesis was impaired in the spinal cord of rats with SNI. Moreover, activation of PGC-1α, the master regulator of mitochondrial biogenesis, attenuates established mechanical allodynia in rats with neuropathic pain. In addition, the neuronal 5-HT1F receptor is significantly downregulated in the spinal cord of rats with neuropathic pain. Furthermore, the selective 5-HT1F receptor agonist lasmiditan attenuated established mechanical allodynia in rats with neuropathic pain. Finally, lasmiditan (Las) treatment restored mitochondrial biogenesis and suppressed neuroinflammation in the spinal cord of rats with SNI. These results provide the first evidence that lasmiditan ameliorates mechanical allodynia in neuropathic pain by inducing mitochondrial biogenesis and suppressing neuroinflammation in the spinal cord. Inducers of mitochondrial biogenesis may be an encouraging therapeutic option for the management of neuropathic pain.

Nrf2 Activation Attenuates Chronic Constriction Injury-Induced Neuropathic Pain via Induction of PGC-1α-Mediated Mitochondrial Biogenesis in the Spinal Cord

BACKGROUND

Neuropathic pain is a debilitating disease with few effective treatments. Emerging evidence indicates the involvement of mitochondrial dysfunction and oxidative stress in neuropathic pain. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a potent regulator of the antioxidant response system. In this study, we investigated whether RTA-408 (RTA, a novel synthetic triterpenoid under clinical investigation) could activate Nrf2 and promote mitochondrial biogenesis (MB) to reverse neuropathic pain and the underlying mechanisms.

METHODS

Neuropathic pain was induced by chronic constriction injury (CCI) of the sciatic nerve. Pain behaviors were measured via the von Frey test and Hargreaves plantar test. The L4-6 spinal cord was collected to examine the activation of Nrf2 and MB.

RESULTS

RTA-408 treatment significantly reversed mechanical allodynia and thermal hyperalgesia in CCI mice in a dose-dependent manner. Furthermore, RTA-408 increased the activity of Nrf2 and significantly restored MB that was impaired in CCI mice in an Nrf2-dependent manner. Peroxisome proliferator-activated receptor-gamma coactivator-1alpha (PGC-1α) is the key regulator of MB. We found that the PGC-1α activator also induced a potent analgesic effect in CCI mice. Moreover, the antinociceptive effect of RTA-408 was reversed by the preinjection of the PGC-1α inhibitor.

CONCLUSIONS

Nrf2 activation attenuates chronic constriction injury-induced neuropathic pain via induction of PGC-1α-mediated mitochondrial biogenesis in the spinal cord. Our results indicate that Nrf2 may be a potential therapeutic strategy to ameliorate neuropathic pain and many other disorders with oxidative stress and mitochondrial dysfunction.

[Venetoclax with low-dose cytarabine for patients with untreated acute myeloid leukemia ineligible for intensive chemotherapy: results from the Chinese cohort of a phase three randomized placebo-controlled trial]

Objective: To investigate the safety and efficacy of venetoclax with low-dose cytarabine (LDAC) in Chinese patients with acute myeloid leukemia (AML) who are unable to tolerate intensive induction chemotherapy. Methods: Adults ≥ 18 years with newly diagnosed AML who were ineligible for intensive chemotherapy were enrolled in this international, randomized, double-blind, placebo-controlled trial. Globally, patients (n=211) were randomized 2∶1 to either venetoclax with LDAC or placebo with LDAC in 28-d cycles, with LDAC on days 1-10. The primary endpoint was OS; the secondary endpoints included response rates, event-free survival, and adverse events. Results: A total of 15 Chinese patients were enrolled (venetoclax arm, n=9; placebo arm, n=6) . The median age was 72 years (range, 61-86) . For the primary analysis, the venetoclax arm provided a 38% reduction in death risk compared with the placebo[hazard ratio (HR) , 0.62 (95%CI 0.12-3.07) ]. An unplanned analysis with an additional 6 months of follow-up demonstrated a median OS of 9.0 months for venetoclax compared with 4.1 months for placebo. The complete remission (CR) rates with CR with incomplete blood count recovery (CRi) were 3/9 (33%) and 0/6 (0%) , respectively. The most common non-hematologic adverse effects (venetoclax vs placebo) were hypokalemia[5/9 (56%) vs 4/6 (67%) ], vomiting[4/9 (44%) vs 3/6 (50%) ], constipation[2/9 (22%) vs 4/6 (67%) ], and hypoalbuminemia[1/9 (11%) vs 4/6 (67%) ]. Conclusion: Venetoclax with LDAC demonstrated meaningful efficacy and a manageable safety profile in Chinese patients consistent with the observations from the global VIALE-C population, making it an important treatment option for patients with newly diagnosed AML who are otherwise ineligible for intensive chemotherapy.

Effects of probiotics on intestinal flora, inflammation and degree of liver cirrhosis in rats with liver cirrhosis by regulating Wnt/β-catenin signaling pathway

We aimed to explore the effects of probiotics on intestinal flora, inflammation and degree of liver cirrhosis in rats with liver cirrhosis, and to verify the Wnt/β-catenin signaling pathway that regulates this process. A total of 30 SD rats were randomly divided into 3 groups, namely, control group (n=10), model group (n=10) and probiotic group (n=10). Rats in the model group were used to construct liver cirrhosis models using carbon tetrachloride (CCL4) method, and those in the probiotic group were administered with probiotic preparations by gavage for 8 weeks. Then the feces of rats in each group were taken to detect the composition of intestinal flora, and changes in the content of inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), monocyte chemotactic protein 1 (MCP-1) and interferon-gamma (IFN-γ), in peripheral blood collected were examined by enzyme-linked immunosorbent assay (ELISA). Next, changes in the degree of liver cirrhosis were analyzed by hematoxylin and eosin (H&E) staining, and the expression levels of the Wnt/β-catenin signaling pathway-related molecules, including β-catenin, glycogen synthase kinase (GSK)-3β and Frizzled-2, in liver tissues in each group were detected via polymerase chain reaction (PCR) and Western blotting (WB). Compared with rats in the control group, those in the model group had a disordered structure of hepatic lobule and hyperplasia of a large number of fibrous tissues. In contrast to those in the model group, the liver lobule structure was greatly improved, the edema cells were obviously reduced, and the hyperplasia of collagen fibers was remarkably alleviated in the probiotic group. Moreover, the degree of liver cirrhosis in the probiotic group was significantly reduced compared with that in the model group. Moreover, the rats in the model group exhibited a higher Bifidobacterium level in the intestinal tract, while those in the probiotic group displayed higher levels of microorganisms in the intestinal tract, such as Lachnospiraceae, Ruminococcaceae, Actinbacteria, Slackia and Pasteurellaceae. In comparison with that in the control group, the level of salt-tolerant Lactobacillus in the intestinal tract of rats in the model group was significantly decreased, while that in the probiotic group was partially increased (P=0.023). Meanwhile, some intestinal flora of rats in the control group, model group and probiotic group were closely correlated. Specifically, highly positive correlations were found between Bacteroidetes and Paraeggerthella (r=0.423, P=0.034) and between Firmicutes and Lactobacillus (r=0.318, P=0.027), but strongly negative associations were detected between Firmicutes and Paraeggerthella (r=-0.691, p=0.004) and between Paraeggerthella and Lactobacillus (r=-0.384, P=0.047). In addition, the levels of inflammatory cytokines TNF-α IL-6, MCP-1 and IFN-γ in the plasma of rats in the model group were markedly higher than those in the control group (P<0.05), whereas such levels in the probiotic group were decreased compared with those in the model group (P<0.05). PCR results revealed that the expression levels of β-catenin and Frizzled-2 in the model group were higher than those in the control group, whereas they were lower in the probiotic group than those in the model group (P<0.05). Furthermore, the model group had a decreased level of GSK-3β in comparison with the control group, but the probiotic group had a higher level of GSK-3β than the model group (P<0.05). WB results were consistent with PCR results. Probiotics can affect intestinal flora, inflammation and degree of liver cirrhosis in rats with liver cirrhosis, and its mechanism may be related to the Wnt/β-catenin signaling pathway.

[The prognostic significance of dynamic monitoring of minimal residual disease (MRD) status in patients with newly-diagnosed multiple myeloma]

Objective: To evaluate the prognostic value of kinetic changes in minimal residual disease (MRD) status, as well as its relationship with risk stratification, therapeutic response and treatment in patients with newly-diagnosed multiple myeloma (MM) . Methods: A total of 135 patients with newly-diagnosed MM were screened, and 105 patients who achieved VGPR or more as the best responses were included into this study. The MRD status was determined by multiparameter flow cytometry (MFC) at multiple intervals after two cycles of treatment until clinical relapse, death, or last follow-up. The statistical methods included Kaplan-Meier analysis, Cox regression, etc. Results: ①In all 135 patients, 57.8% (78/135) patients achieved MRD negativity (MRD(-)) after treatment. In 105 patients who achieved VGPR and thus included in this study, the MRD(-) rate was 72.4% (76/105) , with a median interval of 3 months from starting treatment to achievement of MRD(-) status. ②The 2-year PFS rate of patients with MRD(-) status was significantly higher than that of MRD(+) status (62.2% vs 41.3%, P=0.001) , while MRD persistence (MRD(+)) was an independent factor for poor prognosis (multivariate analysis for PFS: P=0.044, HR=3.039, 95%CI 1.029-8.974) . ③Loss of MRD(-) status (i.e., MRD reappearance) showed inferior outcomes compared with MRD sustained negative ones, the PFS was 18 months versus not reach (P<0.001) and the OS was not reach for both (P=0.002) . ④The 2-year PFS and OS rates of patients with duration of MRD(-)status≥12 months were significantly higher than those of the control group (PFS: 77.7% vs 36.7%, P<0.001; OS: 96.4% vs 57.9%, P<0.001 respectively) . Duration of MRD(-) status was associated with a marked reduction in risk of relapse or death (univariate analysis for PFS: P<0.001, HR=0.865, 95%CI 0.815-0.918; for OS: P=0.001, HR=0.850, 95%CI 0.741-0.915 respectively) . ⑤Moreover, even in patients carrying high-risk cytogenetic abnormalities (CA) or ineligible for ASCT, MRD negativity remained its prognostic value to predict PFS (high-risk CA medianPFS: not reach vs 19 months, P=0.006; ineligible for ASCT medianPFS: not reach vs 25 months, P=0.052 respectively) . ⑥Last, treatment with the bortezomib-based regimens contributed to prolonged MRD(-) duration (median MRD(-) duratio: 25 months vs 10 months, P=0.034) . Conclusion: Our findings supported MRD(+) status as an independent poor prognostic factor in MM patients, which implicated that duration of MRD(-) status also played a significant role in evaluation of prognosis, while loss of MRD(-)status might serve as an early biomarker for relapse. Therefore, monitoring of MRD kinetics might more precisely predict prognosis, as well as guide treatment decision, especially for when to start retreatment in relapsed patients.

[Prognostic analysis of 182 newly diagnosed multiple myeloma patients with high risk cytogenetic abnormalities]

Objectives: To evaluate the clinical characteristics and prognosis of high risk cytogenetic abnormalities (HRCA) and various combinations of cytogenetic abnormality in patients with newly-diagnosed multiple myeloma (NDMM) . Methods: This retrospective study collected 182 NDMM patients in the First Affiliated Hospital of Jilin University between Nov. 2009 and May 2018. HRCA included 1q+, del (17p) , t (4;14) , and t (14;16) detected by FISH, and non-HRCA included del (13q) , t (11;14) detected by FISH. The clinical characteristics among three groups, including cases who carrying a single HRCA, 1 HRCA in combination with non-HRCA and cases carrying two or more HRCAs (double/triple-hit) were observed. Kaplan-Meier curve was used to analyze both progression-free survival (PFS) and overall survival (OS) for the three groups. Results: The survivals of patients with 1 HRCA in combination with non-HRCA were similar to those with two or more HRCAs (double/triple-hit) , the median PFS (mPFS) was 19.1 m vs 12.1 m (P=0.248) and median OS (mOS) was 29.6 m vs 29.3 m (P=0.774) . Furthermore, the prognosis of these two groups were both inferior to patients with a single HRCA, respectively. (mPFS: 32.2 m, P=0.040, P=0.001; mOS: 42.3 m, P=0.021, P=0.041) . Strikingly, both the mPFS and the mOS of patients with 1 HRCA in combination with non-HRCA (regardless of high risk or not) were significantly shorter than that of cases with a single HRCA (mPFS: 15.1 m vs 32.2 m, HR=2.126, 95%CI 1.176-3.843, P=0.005; mOS: 29.3 m vs 42.3 m, HR=1.442, 95%CI 0.705-2.950, P=0.011) . Conclusion: It is of prognostic significance value for detecting double/triple-hit based on FISH cytogenetics in NDMM.

[A retrospective study of the BiRd regimen in the treatment of relapsed/ refractory multiple myeloma]

Objective: To evaluate efficacy of the BiRd regimen, a combination of clarithromycin, lenalidomide, and dexamethasone, in the treatment of patients with relapsed/refractory multiple myeloma (RRMM) . Methods: Patients with RRMM treated with BiRd between September 11, 2013 and August 1, 2016 at six centers were included to evaluate overall survival rate (ORR) , clinical benefit rate (CBR) , progression-free survival (PFS) , overall survival (OS) , as well as adverse events. Results: Of 30 patients with RRMM, 27 patients were evaluable, and ORR and CBR were 51.9% (14/27) and 66.7% (18/27) respectively, including 1 sCR (3.7%) , 3 CR (11.1%) , 3 VGPR (11.1%) , and 7 PR (25.6%) . In 13 patients with prior Rd, ORR and CBR were 38.5% (5/13) and 61.5% (8/13) respectively, of which 5 patients with ≥MR carried high-risk cytogenetic[ (e.g.17p- or t (4;14) ] together with at least one of other adverse-prognostic cytogenetic (e.g.13q- and/or 1q21+) . In 24 patients with prior bortezomib-based therapy, ORR and CBR were 45.8 and 62.5%, respectively. With a median follow-up time of 14.9 (range 1.0-33.8) months, the median PFS and OS were 12.0 (95%CI 11.6-12.4) and 27.6 (95%CI 15.1-40.1) months, respectively. The BiRd regimen was well tolerated. Conclusion: The BiRd regimen is an effective and safety protocol for RRMM, including those carrying high-risk cytogenetic markers.

[Efficacy and safety of IA regimen containing different doses of idarubicin in de-novo acute myeloid leukemia for adult patients]

目的

探讨含不同剂量去甲氧柔红霉素（IDA 8、10、12 mg/m²）的IA方案诱导治疗成人初发急性髓系白血病（AML）（非急性早幼粒细胞白血病）的临床疗效和安全性。

方法

采用多中心、单盲、非随机、临床对照研究，纳入2011年5月至2015年3月苏州大学附属第一医院及其他36家单位收治的1 215例成人初发AML患者，根据诱导化疗方案中IDA的剂量对患者进行分组，分析不同剂量IDA联合阿糖胞苷（100 mg/m²）组成的IA方案在成人初发AML诱导治疗中的完全缓解（CR）率、血液学及非血液学不良事件。

结果

可纳入缓解率分析的AML患者共1 207例，IDA 8 mg/m²、10 mg/m²和12 mg/m²组的CR率分别为73.6%（215/292）、84.1%（662/787）和86.7%（111/128），差异有统计学意义（P<0.001）；以IDA 8 mg/m²组为参照组，在调整了年龄、骨髓原始细胞比例、FAB分型、危险度分层后，IDA 10 mg/m²和IDA 12 mg/m²为影响患者CR的有利因素[OR=0.49（95% CI 0.34~0.70），P<0.001；OR=0.36（95%CI 0.18~0.71），P=0.003]。在中、低危组中三组CR率分别为76.5%（163/213）、86.9%（506/582）和86.1%（68/79），差异有统计学意义（P=0.007）；在调整了年龄、骨髓原始细胞比例、FAB分型因素后，IDA 10 mg/m²为影响患者CR的有利因素[OR=0.47（95% CI 0.31~0.71），P<0.001]。在高危组中，三组CR率分别为50.0%（18/36）、60.6%（43/71）和81.8%（18/22），差异无统计学意义（P=0.089），但在调整了年龄、骨髓原始细胞比例、FAB分型因素后，IDA 12 mg/m²为影响患者CR的有利因素[OR=0.22（95% CI 0.06~0.80），P=0.022]。8 mg/m²、10 mg/m²和12 mg/m²组中性粒细胞≤0.5×10⁹/L的中位持续时间分别为14（11~18）、15（11~20）和18（14~22）d，差异有统计学意义（P=0.012）；三组PLT≤20×10⁹/L的中位持续时间分别为14（7~17）、15（11~20）和17（15~21）d，差异有统计学意义（P=0.001）；三组肺部感染发生率分别为9.8%、13.5%和25.2%，差异有统计学意义（P<0.001）。

结论

在中国成人（18~60岁）初发AML中，建议中、低危组患者采用含IDA 10 mg/m²的IA方案进行诱导治疗；而高危组AML建议选择含IDA 12 mg/m²的IA方案进行诱导治疗。

[Clinical significance of loop electrosurgical excisional procedure in diagnosis and treatment of cervical adenocarcinoma in situ and invasive cervical adenocarcinoma]

Objective: To evaluate the accuracy of colposcopic biopsy on diagnosis of cervical adenocarcinoma in situ (AIS) and the clinical significance of loop electrosurgical excisional procedure (LEEP) on diagnosis and treatment of AIS and invasive adenocarcinoma. Methods: All medical records of 193 patients diagnosed as AIS by colposcopic biopsy and (or) AIS or invasive adenocarcinoma diagnosed by LEEP conization from Jan. 2015 to Dec. 2016 in Obstetrics and Gynecology Hospital of Fudan University were retrospectively reviewed. The final diagnosis was based on colposcopic biopsy or LEEP or the highest grade of pathological diagnosis after hysterectomy. Results: In the 193 patients, 155 cases were finally diagnosed as AIS and 38 cases as invasive adenocarcinoma by histopathologic examination. Among the 155 AIS patients, 21.9% (34/155) had positive cone margins, in which 26 patients had hysterectomy, 30.8% (8/26) had residual disease in hysterectomy specimens; 78.1% (121/155) had negative cone margins, 68 patients with negative margins had hysterectomy and 5.9% (4/68) had residual disease, which was significantly lower than that with positive margins (χ(2)=10.46, P=0.001) . One hundred and twenty from one hundred ninty-three (62.3%, 120/193) with AIS were detected by colposcopy. Pathological diagnosis of 50.8% (98/193) cases were upgraded after LEEP conization. Conclusions: Colposcopy is indispensable for the diagnosis of AIS, but accurate diagnosis should be made by LEEP. LEEP is capable of detecting AIS or cervical adenocarcinoma that was misdiagnosed by colposcopy, which is a pivotal method for accurate diagnosis. The margin status of LEEP is important for patients in choosing further hysterectomy, but the presence of cervical adenocarcinoma should always be aware of.

Decitabine treatment for acute myeloid leukemia relapse after allogeneic hematopoietic stem cell transplantation

Therapeutic options for patients with relapse of acute myeloid leukemia (AML) after allo-SCT are limited. Here, we present a case of a 49-year female with AML who underwent myeloablative allo-SCT from a matched sibling donor. Seven months after transplantation she developed cGVHD and suffered from extramedullary plus concurrent medullary relapse. The presence of CNS extramedullary disease is unique. Our patient was treated with decetabine. After one cycle the patient achieved complete remission and full donor chimerism without severe side effects or the occurrence of GVHD. Our case report, together with previous studies, provides strong evidence that decitabine may be a suitable treatment option for AML relapse after allogeneic transplantation, especially in patients who developed GVHD.

[Mid- to long-term outcomes of cervical disc arthroplasty for symptomatic cervical disc disease: a meta-analysis]

Objective: To compare the benefits and harms of cervical disc arthroplasty (CDA) with anterior cervical discectomy and fusion(ACDF) for symptomatic cervical disc disease at mid- to long-term follow-up. Methods: Electronic searches were made in PubMed, EMBASE, and the Cochrane Library for randomized controlled trials with at least 48 moths follow-up.Outcomes were reported as relative risk or standardized mean difference.Meta-analysis was carried out using Revman version 5.3 and Stata version 12.0. Results: Seven trials were included, involving 2 302 participants.The results of this meta-analysis indicated that CDA brought about fewer secondary surgical procedures, lower neck disability index (NDI) scores, lower neck and arm pain scores, greater SF-36 Physical Component Summary (PCS) and Mental Component Summary(MCS) scores, greater range of motion (ROM) at the operative level and less superior adjacent-segment degeneration(P<0.05) than ACDF.CDA was not statistically different from ACDF in inferior adjacent-segment degeneration, neurological success, and adverse events (P>0.05). Conclusions: CDA can significantly reduce the rates of secondary surgical procedures compared with ACDF.Meanwhile, CDA is superior or equivalent to ACDF in other aspects.As some studies without double-blind are included and some potential biases exites, more randomized controlled trials with high quality are required to get more reliable conclusions.

CIAPIN1 gene silencing enhances chemosensitivity in a drug-resistant animal model in vivo

Overexpression of cytokine-induced apoptosis inhibitor 1 (CIAPIN1) contributes to multidrug resistance (MDR) in breast cancer. This study aimed to evaluate the potential of CIAPIN1 gene silencing by RNA interference (RNAi) as a treatment for drug-resistant breast cancer and to investigate the effect of CIAPIN1 on the drug resistance of breast cancer in vivo. We used lentivirus-vector-based RNAi to knock down CIAPIN1 in nude mice bearing MDR breast cancer tumors and found that lentivirus-vector-mediated silencing of CIAPIN1 could efficiently and significantly inhibit tumor growth when combined with chemotherapy in vivo. Furthermore, Western blot analysis showed that both CIAPIN1 and P-glycoprotein expression were efficiently downregulated, and P53 was upregulated, after RNAi. Therefore, we concluded that lentivirus-vector-mediated RNAi targeting of CIAPIN1 is a potential approach to reverse MDR of breast cancer. In addition, CIAPIN1 may participate in MDR of breast cancer by regulating P-glycoprotein and P53 expression.

Cloning and bioinformatic analysis of an acidophilic beta-mannanase gene, Anman5A, from Aspergillus niger LW-1

Using 3' and 5' rapid amplification of cDNA ends (RACE) techniques, the full-length cDNA sequence of the AnmanSA, a gene that encodes an acidophilic beta-mannanase of Aspergillus niger LW-1 (abbreviated to AnMan5A), was identified from the total RNA. The cDNA sequence was 1417 bp in length, harboring 5'- and 3'-untranslated regions, as well as an open reading frame (ORF) which encodes a 21-aa signal peptide, a 17-aa propeptide and a 345-aa mature peptide. Based on the topology of the phylogenetic tree of beta3-mannanases from glycoside hydrolase (GH) family 5, the AnMan5A belongs to the subfamily 7 of the GH family 5. Its 3D structure was modeled by the bitemplate-based method using both MODELLER 9.9 and SALIGN programs, based on the known beta-mannanase crystal structures of Trichoderma reesei (1QNO) and Lycopersicon esculentum (1RH9) from the GH family 5. In addition, the complete DNA sequence of the Anman5A was amplified from the genomic DNA using the pUCm-T vector-mediated PCR and conventional PCR methods. The DNA sequence was 1825 bp in length, containing a 5'-flanking regulatory region, 2 introns and 3 exons when compared with the full-length cDNA.

CNS gene transfer mediated by a novel controlled release system based on DNA complexes of degradable polycation PPE-EA: a comparison with polyethylenimine/DNA complexes

Nonviral gene delivery systems based upon polycation/plasmid DNA complexes are quickly gaining recognition as an alternative to viral gene vectors for their potential in avoiding immunogenicity and toxicity problems inherent in viral systems. We investigated in this study the feasibility of using a controlled release system based on DNA complexed with a recently developed polymeric gene carrier, polyaminoethyl propylene phosphate (PPE-EA), to achieve gene transfer in the brain. A unique feature of this gene delivery system is the biodegradability of PPE-EA, which can provide a sustained release of DNA at different rates depending on the charge ratio of the polymer to DNA. PPE-EA/DNA complexes, naked DNA, and DNA complexed with polyethylenimine (PEI), a nondegradable cationic polymer known to be an effective gene carrier, were injected intracisternally into the mouse cerebrospinal fluid. Transgene expression mediated by naked DNA was mainly detected in the brain stem, a region close to the injection site. With either PPE-EA or PEI as a carrier, higher levels of gene expression could be detected in the cerebral cortex, basal ganglia, and diencephalons. Transgene expression in the brain mediated by PPE-EA/DNA complexes at an N/P ratio of 2 persisted for at least 4 weeks, with a significant higher level than that produced by either naked plasmid DNA or PEI/DNA at the 4-week time point. Furthermore, PPE-EA displayed much lower toxicity in cultured neural cells as compared to PEI and did not cause detectable pathological changes in the central nervous system (CNS). The results established the potential of PPE-EA as a new and biocompatible gene carrier to achieve sustained gene expression in the CNS.

Repeated intrathecal administration of plasmid DNA complexed with polyethylene glycol-grafted polyethylenimine led to prolonged transgene expression in the spinal cord

Gene delivery into the spinal cord provides a potential approach to the treatment of spinal cord traumatic injury, amyotrophic lateral sclerosis, and spinal muscular atrophy. These disorders progress over long periods of time, necessitating a stable expression of functional genes at therapeutic levels for months or years. We investigated in this study the feasibility of achieving prolonged transgene expression in the rat spinal cord through repeated intrathecal administration of plasmid DNA complexed with 25 kDa polyethylenimine (PEI) into the lumbar subarachnoid space. With a single injection, DNA/PEI complexes could provide transgene expression in the spinal cord 40-fold higher than naked plasmid DNA. The transgene expression at the initial level persisted for about 5 days, with a low-level expression being detectable for at least 8 weeks. When repeated dosing was tested, a 70% attenuation of gene expression was observed following reinjection at a 2-week interval. This attenuation was associated with apoptotic cell death and detected even using complexes containing a noncoding DNA that did not mediate any gene expression. When each component of the complexes, PEI polymer or naked DNA alone, were tested in the first dosing, no reduction was found. Using polyethylene glycol (PEG)-grafted PEI for DNA complexes, no attenuation of gene expression was detected after repeated intrathecal injections, even in those rats receiving three doses, administered 2 weeks apart. Lumbar puncture is a routine and relatively nontraumatic clinical procedure. Repeated administration of DNA complexed with PEG-grafted PEI through this less invasive route may prolong the time span of transgene expression when needed, providing a viable strategy for the gene therapy of spinal cord disorders.

Polyethylene glycol modified polyethylenimine for improved CNS gene transfer: effects of PEGylation extent

Poor solubility of polycation complexes with DNA is one drawback for their in vivo use as gene delivery systems. PEGylation often can improve the solubility of the complexes, minimize their aggregation and reduce their interaction with proteins in the physiological fluid. We investigated in vivo application of polyethylene glycol (PEG) modified polyethylenimine (PEI) for gene expression in the central nervous system. Varied numbers of linear PEG (2 kDa) were grafted to branched PEI (25 kDa) from the average number of PEG per one PEI macromolecule at 1-14.5. While higher degrees of PEG grafting did not improve gene expression, a PEI conjugate with one segment of PEG was able to mediate transgene expression in the spinal cord up to 11-fold higher than PEI homopolymer after intrathecal administration of its DNA complexes into the lumbar spinal cord subarachnoid space. Improved gene expression with this conjugate was observed as well in the brain after the lumbar injection. As assessed in in vitro studies, the PEI conjugate with a low degree of PEG grafting was able to reduce the size of polymer DNA complexes, prevent the aggregation of complexes, decrease the interactions of the complexes with serum proteins, counter the inhibition of serum to gene transfer, and enhance transfection efficiency, although not significant in affecting complex formation and reducing in vitro cell toxicity of PEI. The study provides the in vivo evidence that an appropriate degree of PEG modification is decisive in improving gene transfer mediated by PEGylated polymers.

Reverse transcription slippage over the mRNA secondary structure of the LIP1 gene

The secondary structures in mRNA often cause early termination during the synthesis of cDNA. In an attempt to determine the 5'-untranslated region (UTR) of the gene LIP1 using the RNA ligase-mediated rapid amplification of cDNA ends (RLM-RACE), we found that reverse transcriptases skipped over the LIP1 RNA secondary structures and continued the DNA synthesis through RNA adapter sequences without early termination. A fragment of only three nucleotides upstream of the LIP1 translation initiation codon was obtained from the initial RACE-PCR, which was much shorter than the 57-nucleotide fragment obtained from the cDNA library screening. Analysis of the 5' end sequence indicates the presence of high G+C content and stem-loop secondary structures. Therefore, optimizations of the reaction with high temperature (70 degrees C) and a thermostable reverse transcriptase were performed to synthesize the first-strand cDNA, which was determined to have 73 nucleotides in the 5'-UTR. These results suggest that, under cDNA synthesis conditions at 42 degrees C and 60 degrees C, the reverse transcriptases skipped over the stem-loop structures of LIP1 mRNA and continued the cDNA synthesis until they reached the RNA adapter sequences. Thisfinding draws attention to adopting optimized conditions for cDNA synthesis on G+C-rich RNA templates.

Seroprevalence of Kaposi's sarcoma-associated herpesvirus infection among blood donors from Texas

PURPOSE

Kaposi's sarcoma-associated herpesvirus (KSHV), a gammaherpesvirus recently discovered among AIDS patients with Kaposi's sarcoma, is a potential candidate for screening in blood and plasma donors. While a number of studies have assessed KSHV infection among U.S. blood donors, larger-scale population-based studies would be necessary to develop more refined estimates of the magnitude and variation of KSHV infection across different geographic regions of the U.S. blood supply. The goal of the present study, therefore, was to determine the seroprevalence of KSHV infection and to assess demographic correlates of KSHV infection among south Texas blood donors.

METHODS

KSHV infection was determined using specific serologic assays that measure antibodies to KSHV latent and lytic antigens.

RESULTS

The overall seroprevalence of KSHV in Texas blood donors (15.0%) is substantially higher than previously reported among blood donor and general population samples in the United States. This high rate of KSHV infection persisted across most of the sociodemographic subgroups under study but was particularly elevated among participants with less than a high school education. The infection rate also increased linearly with age.

CONCLUSIONS

The elevated infection rate reported in the present study suggests that screening methods to detect KSHV infection in blood donors should be considered. In view of the etiologic role of KSHV for several malignancies, it would be important for future studies to directly assess the risk of KSHV transmission via blood transfusion.

Transgene Expression in the Brain Stem Effected by Intramuscular Injection of Polyethylenimine/DNA Complexes

Gene delivery into the CNS without tissue destruction is challenging. As neurons are capable of taking up exogenous particulates from the muscles that they innervate, we investigated the feasibility of achieving gene transfer in CNS neurons by peripheral intramuscular injection of plasmid DNA complexed with the cationic polymer polyethylenimine (PEI) in the rat hypoglossal system. Using the luciferase reporter gene driven by a Rous sarcoma virus promoter, transgene expression of up to 4 x 10(6) RLU per brain stem at 20 microg of plasmid DNA was achieved after tongue injection. Using lacZ as a reporter gene, transgene expression in the brain stem was detected in hypoglossal motor neurons, a group of neurons that innervate tongue muscles. The plasmid DNA was detected by PCR analysis in the brain-stem samples, demonstrating that the PEI/DNA complexes had migrated by retrograde axonal transport to neuronal cell bodies in the brain stem after being internalized by nerve terminals in the tongue muscle. Using a therapeutic bcl-2 gene driven by a cytomegalovirus promoter and Western blotting, transgene expression was detectable in the brain stem as early as 18 h after tongue injection and lasted for at least 2 weeks. Two lipid transfection agents, GenePORTER and TransFast, mediated a weak gene expression in the hypoglossal system, but not two polymers, poly-l-lysine and chitosan. The nonviral neuronal gene delivery method established in this study bypasses the blood-brain barrier and suggests a possible therapeutic strategy for noninvasive CNS gene transfer.

Suppression of oncogenic viral interferon regulatory factor (vIRF) of Kaposi's sarcoma-associated herpesvirus by ribozyme-mediated cleavage

Kaposi's sarcoma-associated herpesvirus/human herpesvirus 8 (KSHV/HHV8) has been etiologically associated with several malignancies including Kaposi's sarcoma and primary effusion lymphoma. Oncogenic viral interferon regulatory factor (vIRF) encoded by KSHV ORF-K9 is a homologue of cellular interferon regulatory factor (IRF), and has been demonstrated to inhibit type I/II interferon signal transduction and transform NIH3T3 cells through the interactions with IRF-1, IRF-3, and CBP/p300 proteins. To counteract vIRF's pathogenic role, we have developed five ribozymes targeting ORF-K9 mRNA to suppress vIRF expression. The vIRF RNA substrates were cleaved up to 80% in a substrate-specific manner in transcript cleavage assays in vitro. In a transient transfection assay, two of the ribozymes efficiently suppressed the expression of vIRF protein measured by dual-color immunofluorescence assay that simultaneously detects the expression of both vIRF protein and ribozyme. Flow cytometry analysis showed that these ribozymes reduced vIRF expression up to 76%. A mutant ribozyme had no cleavage activity in vitro, but exhibited antisense effect in vivo. These results suggest that the ribozymes may provide a new approach for functional knockout of vIRF gene, and are potential candidates of antiviral therapy for KSHV-related malignancies.

Characterization of the promoter region of the viral interferon regulatory factor encoded by Kaposi's sarcoma-associated herpesvirus

Viral interferon regulatory factor (vIRF) encoded by Kaposi's sarcoma-associated herpesvirus (KSHV) inhibits the expression of interferon-responsive genes, causes cellular transformation and transactivates KSHV genes. In the present study, we characterized the mRNA expression pattern of the vIRF gene and its promoter. A vIRF transcript of 1.7 kb in size was detected in low level in uninduced KSHV-infected cells and its expression was inducible by 12-O-tetradecanoylphorbol-13-acetate (TPA), sensitive to cycloheximide and resistant to phosphonoacetic acid. The transcription start site was mapped to 79 nt upstream of the ATG initiation site by 5'-RACE. Mutagenesis analysis identified a region between -56 and the transcription start site (+1) as the minimal promoter region that contains a functional TATA box at -27. A region between -337 and -125 contains a repressor domain negated by sequence from -991 to -499 in BCBL-1 cells, a region which was also identified to be responsive to TPA induction. These results demonstrate vIRF as a KSHV early gene, identify its promoter and define the promoter regions that contain regulatory elements controlling vIRF transcription.

Distinct distribution of rare US genotypes of Kaposi's sarcoma-associated herpesvirus (KSHV) in South Texas: implications for KSHV epidemiology

Genotypes of Kaposi's sarcoma (KS)-associated herpesvirus (KSHV) from patients with KS in South Texas were examined. Open-reading frame (ORF)-K1 and ORF-K15 DNA segments from 16 KSHV isolates were amplified by polymerase chain reaction, and KSHV subtypes were assigned on the basis of sequence variations. K1 genotyping showed that 75% exhibited C subtype and 25% exhibited A subtype. K15 genotyping showed that 56% exhibited M form, of which 89% exhibited C3 K1 subtype and 44% exhibited P form. A unique isolate was found and was classified as C6 clade. All of the M KSHV isolates had been obtained from human immunodeficiency virus-negative classic KS patients >50 years of age, of whom 78% were Hispanic. Conversely, all KS patients with AIDS were <36 years of age and exhibited P form KSHV. These findings indicate that C3/M KSHV genotypes are more prevalent in South Texas (50%) than in other US regions (3%) and that M form KSHV likely existed in this region long before the AIDS epidemic.

Evaluation of human herpesvirus type 8 infection in childhood langerhans cell histiocytosis

The etiology of Langerhans cell histiocytosis (LCH) is unknown. Viral causes, including human herpesvirus type 6 (HHV6), have been suggested but remain unproved. The recently discovered human herpesvirus type 8 (HHV8), the cause of Kaposi's sarcoma, infects dendritic cells in the bone marrow associated with multiple myeloma. Evidence for an association of HHV8 infection with LCH in children was studied by two approaches: indirectly by HHV8-specific serologic assays and directly by detection of HHV8 sequences using polymerase chain reaction in affected bone marrow samples. Using three different assays specific for HHV8 antibodies, 3 of 10 (30%) children with LCH had detectable HHV8 antibodies, which was not different from the prevalence of 5 of 30 (17%) in healthy controls of similar age (P = 0.65). Of bone marrow samples from three additional children with LCH, all had amplifiable DNA but were negative for HHV8 sequences. These studies of a small number of patients do not demonstrate an increased prevalence of HHV8 infection in children with LCH, and they do not suggest a causal role for HHV8 in the etiology of LCH.

Kaposi's sarcoma-associated herpesvirus gene sequences are detectable at low copy number in primary amyloidosis

Primary amyloidosis (AL), like multiple myeloma (MM), results from a clonal proliferation of plasma cells. Recent detection of Kaposi's sarcoma-associated herpesvirus (KSHV) gene sequences in MM patients, although controversial, suggested that KSHV may also be present in AL. In the present study, we assayed for KSHV gene sequences in patients with primary AL independently in 2 laboratories. Nested polymerase chain reaction (PCR) was performed on DNA isolated from 21 bone marrow (BM) core biopsy samples to amplify orf26 and orf72, 2 regions of the KSHV genome. Eighteen of 21 (86%) BM core biopsy samples were KSHV PCR positive. BM aspirates from 16 of these 21 AL patients were cultured for 4-6 weeks to generate long term bone marrow stromal cells (LT-BMSCs), and 13 of 16 (81%) LT-BMSCs were also KSHV PCR positive. Results in all but 1 sample were consistent in the 2 laboratories. Sequencing of the PCR products in the 2 laboratories confirmed 94-98% and 95-98% homology to the published orf 26 and orf 72 KSHV gene sequences respectively, with interpatient base pair differences. Despite the presence of KSHV gene sequences, only 4/18 (22%) KSHV PCR positive patients demonstrated KSHV lytic antibodies by immunoblot assay. A sensitive assay performed on the BCBL-1 cell line confirmed the presence of KSHV at a very low copy number in AL. PCR using patient specific light chain gene primers also amplified DNA isolated from 2 AL BM core biopsies and 3 AL LT-BMSCs which were KSHV PCR positive, suggesting the presence of clonotypic cells. Our results therefore demonstrate KSHV gene sequences albeit at a very low copy number in the majority of BM core biopsies and LT-BMSCs from AL patients, and serological responses in only a minority of cases. Ongoing studies to identify viral transcripts and gene products will determine the biological relevance of KSHV in AL disease pathogenesis.

Absence of herpesvirus DNA sequences in the 5T murine model of human multiple myeloma

Kaposi's sarcoma-associated herpesvirus (KSHV, also known as HHV-8) has been found in patients with multiple myeloma (MM) and postulated to be aetiologically associated with the development of this common plasma cell malignancy. A murine model of MM was previously established in which intravenous transfer of 5T myeloma cells into C57BL/KaLwRij mice resulted in characteristic features of human MM. In the present study, we sought to identify herpesvirus DNA sequences in this murine model of MM through polymerase chain reaction (PCR) analysis using primers specific for KSHV, murine herpesvirus 68 (MHV68) and murine cytomegalovirus (MCMV) as well as consensus primers designed from the highly conserved DNA polymerase genes of the Herpesviridae family. None of the DNA samples from whole bone marrow (n = 6) or dendritic cells enriched by long-term culture (n = 8) of 5T myeloma-bearing mice as well as the 5T myeloma cell lines (n = 3) maintained in long-term culture yielded specific amplification products in any of the PCR assays. Two KSHV-specific serological assays measuring antibodies to KSHV latent and lytic antigens also failed to detect the presence of anti-KSHV antibodies in mice that developed MM. These results suggest that the development of 5T murine MM is unlikely to be involved with KSHV or a KSHV-like murine herpesvirus.

Epidemiology of herpesvirus papio infection in a large captive baboon colony: similarities to Epstein-Barr virus infection in humans

The epidemiology of herpesvirus papio, a lymphocryptovirus similar to Epstein-Barr virus (EBV), was studied in a captive colony of >1900 baboons. Herpesvirus papio IgG antibody titers were measured by IFA. In total, 438 specimens from 296 baboons were assessed, including 116 serial specimens from 52 juveniles and 6 infants studied monthly for 1 year following birth and at age 18 months. Maternally derived antibody reached a nadir at 4 months of age. About 75% of animals at 12 months of age and >95% of animals after age 24 months demonstrated serologic evidence of herpesvirus papio infection. After age 3 years, the geometric mean titer was 1:60-75. The epidemiology of herpesvirus papio infection in baboons closely parallels that of EBV infection in humans. An animal model of lymphocryptovirus infection will facilitate investigations of human lymphocryptovirus biology.

Molecular polymorphism of Kaposi's sarcoma-associated herpesvirus (Human herpesvirus 8) latent nuclear antigen: evidence for a large repertoire of viral genotypes and dual infection with different viral genotypes

Molecular polymorphism was found in Kaposi's sarcoma-associated herpesvirus (KSHV) latent nuclear antigen (LNA), mapped to the internal repeat domain of the encoding orf73 gene, and used to develop a novel genotyping technique, KSHV LNA genotyping (KVNAtyping). KVNAtype was stable during latent and lytic viral replication in cell culture and in humans. Diverse KVNAtypes were identified in 43 specimens: 6 KSHV cell lines and 6 Kaposi's sarcoma (KS) and 4 primary effusion lymphoma (PEL) tumor samples from the United States, 15 KS tumor samples from Italy, and 12 KS tumor samples from Zambia. A single KVNAtype was detected in each of 41 specimens, and 2 KVNAtypes were detected in each of 2 KS specimens. Multifocal KS from 3 patients showed the same single KVNAtype at all sites in each patient. These results demonstrate a large repertoire of KSHV genotypes and suggest that the development of most KSs and PELs is associated with a single viral genotype.

Kaposi's sarcoma-associated herpesvirus: a sexually transmissible infection?

We examined sexual behavior as a risk factor for Kaposi's sarcoma-associated herpesvirus (KSHV) infection and examined the relation between KSHV seropositivity and development of KS in cross-sectional and cohort studies of 130 homosexual men diagnosed with AIDS in Sydney, Australia during the period from 1991 to 1993. KSHV serology was measured using antibody tests to latency-associated nuclear antigen (LANA) and lytically expressed open reading frame (ORF) 65.2. In the cross-sectional analysis, 52% (68) of study subjects were KSHV-seropositive by either assay. KSHV-seropositive men were significantly more likely to be seropositive to both herpes simplex type 2 (odds ratio [OR] 3.0; 95% confidence interval [CI], 1.2-7.5 for LANA and OR 2.8; 95% CI, 1.3-6.0 for ORF 65) and hepatitis A virus (OR 2.2; 95% CI, 1.1-4.5 for ORF 65). KSHV-seropositive men reported nonsignificantly more casual sexual partners and were nonsignificantly more likely to report insertive oroanal contact with casual partners. These data suggest that KSHV might be sexually transmitted among homosexual men. Men were observed until October 1996 for development of KS. Those seropositive to either KSHV assay at baseline were more likely than the seronegative to develop KS during follow-up (rate ratio [RR] 4.4; 95% CI, 1.9-10.2). Of those seropositive for KSHV, 53% developed KS.

Human herpesvirus-8 (HHV-8) associated with small non-cleaved cell lymphoma in a child with AIDS

The association of human herpesvirus-8 (HHV-8) with a small non-cleaved cell lymphoma is described in a child with the acquired immunodeficiency syndrome (AIDS) who developed a malignant pleural effusion and radiologic evidence of multiple solid tumors. HHV-8 DNA and Epstein-Barr virus DNA were identified in pleural fluid cells by polymerase chain reaction (PCR) amplification. The serum antibody titer against lytic HHV-8 proteins was 1:640; antibodies to latent HHV-8 proteins were not detected. Cytogenetic analysis of malignant cells revealed three abnormal karyotypes sharing the common finding of a t(8;14) translocation. Rearrangement of c-myc was demonstrated by PCR analysis. Oligoclonal JH immunoglobulin bands were found. Insufficient pleural fluid cells were available to permit localization of HHV-8 to malignant cells by in situ hybridization. This malignancy contrasts with HHV-8-associated lymphomas reported in adult patients with AIDS with respect to cell morphology, c-myc translocation, and oligoclonal immunoglobulin gene rearrangement. HHV-8 is associated with a wider spectrum of malignancies than recognized previously.

Antibodies to Kaposi's sarcoma-associated herpesvirus (human herpesvirus 8) in patients with multiple myeloma

Kaposi's sarcoma-associated herpesvirus (KSHV) serologic assays were used to detect specific antibodies to KSHV lytic and latent antigens in 27 patients with multiple myeloma, 27 control patients with other cancers, and 50 random blood donors. Antibodies to KSHV recombinant minor capsid antigen orf65 were found in 81% of patients with multiple myeloma, 22% of control patients with other cancers, and 6% of the blood donors. Antibodies to KSHV latent nuclear antigens were found in 52% of patients with multiple myeloma, 26% of control patients with other cancers, and 2% of the blood donors. All of the 11 patients with progressive multiple myeloma were KSHV-seropositive. Antibodies to Epstein-Barr virus nuclear antigen 1 were present in 89% of patients with multiple myeloma, 93% of control patients with other cancers, and 88% of the blood donors. These data support the possible association of KSHV infection with multiple myeloma, particularly with progressive disease.

Artificial imitation of glutathione peroxidase with 6-selenium-bridged beta-cyclodextrin

On the basis of cyclodextrin, 6-selenium bridged beta-cyclodextrin (6-beta-CD-Se-Se-beta-CD, known as 6-SeCD) was synthesized by the selective tosylation of beta-cyclodextrin and nucleophilic displacement by sodium hydroselenide to imitate glutathione peroxidase (GPX). The GPX activity of diselenide 6-SeCD is 4.3 times that of PZ51. The structure of the mimic 6-SeCD was characterized by means of laser mass spectroscopy, elemental analysis, IR and 1H NMR. The selenium content and its valence in 6-SeCD were determined by means of X-ray photoelectron spectra. Kinetics of the mimic showed that its enzymatic behavior was similar to that of native GPX.