FIH-1-modulated HIF-1α C-TAD promotes acute kidney injury to chronic kidney disease progression via regulating KLF5 signaling

Incomplete recovery from episodes of acute kidney injury (AKI) can predispose patients to develop chronic kidney disease (CKD). Although hypoxia-inducible factor-1α (HIF-1α) is a master regulator of the response to hypoxia/ischemia, the role of HIF-1α in CKD progression following incomplete recovery from AKI is poorly understood. Here, we investigated this issue using moderate and severe ischemia/reperfusion injury (I/RI) mouse models. We found that the outcomes of AKI were highly associated with the time course of tubular HIF-1α expression. Sustained activation of HIF-1α, accompanied by the development of renal fibrotic lesions, was found in kidneys with severe AKI. The AKI to CKD progression was markedly ameliorated when PX-478 (a specific HIF-1α inhibitor, 5 mg· kg-1·d-1, i.p.) was administered starting on day 5 after severe I/RI for 10 consecutive days. Furthermore, we demonstrated that HIF-1α C-terminal transcriptional activation domain (C-TAD) transcriptionally stimulated KLF5, which promoted progression of CKD following severe AKI. The effect of HIF-1α C-TAD activation on promoting AKI to CKD progression was also confirmed in in vivo and in vitro studies. Moreover, we revealed that activation of HIF-1α C-TAD resulted in the loss of FIH-1, which was the key factor governing HIF-1α-driven AKI to CKD progression. Overexpression of FIH-1 inhibited HIF-1α C-TAD and prevented AKI to CKD progression. Thus, FIH-1-modulated HIF-1α C-TAD activation was the key mechanism of AKI to CKD progression by transcriptionally regulating KLF5 pathway. Our results provide new insights into the role of HIF-1α in AKI to CKD progression and also the potential therapeutic strategy for the prevention of renal diseases progression.

Synergisms of genome and metabolism stabilizing antitumor therapy (GMSAT) in human breast and colon cancer cell lines: a novel approach to screen for synergism

BACKGROUND

Despite an improvement of prognosis in breast and colon cancer, the outcome of the metastatic disease is still severe. Microevolution of cancer cells often leads to drug resistance and tumor-recurrence. To target the driving forces of the tumor microevolution, we focused on synergistic drug combinations of selected compounds. The aim is to prevent the tumor from evolving in order to stabilize disease remission. To identify synergisms in a high number of compounds, we propose here a three-step concept that is cost efficient, independent of high-throughput machines and reliable in its predictions.

METHODS

We created dose response curves using MTT- and SRB-assays with 14 different compounds in MCF-7, HT-29 and MDA-MB-231 cells. In order to efficiently screen for synergies, we developed a screening tool in which 14 drugs were combined (91 combinations) in MCF-7 and HT-29 using EC25 or less. The most promising combinations were verified by the method of Chou and Talalay.

RESULTS

All 14 compounds exhibit antitumor effects on each of the three cell lines. The screening tool resulted in 19 potential synergisms detected in HT-29 (20.9%) and 27 in MCF-7 (29.7%). Seven of the top combinations were further verified over the whole dose response curve, and for five combinations a significant synergy could be confirmed. The combination Nutlin-3 (inhibition of MDM2) and PX-478 (inhibition of HIF-1α) could be confirmed for all three cell lines. The same accounts for the combination of Dichloroacetate (PDH activation) and NHI-2 (LDH-A inhibition). Our screening method proved to be an efficient tool that is reliable in its projections.

CONCLUSIONS

The presented three-step concept proved to be cost- and time-efficient with respect to the resulting data. The newly found combinations show promising results in MCF-7, HT-29 and MDA-MB231 cancer cells.

Inhibition of HIF-1α enhances anti-tumor effects of dendritic cell-based vaccination in a mouse model of breast cancer

Considerable evidence shows that the tumor microenvironment is an active participant in preventing immunosurveillance and limiting the efficacy of anticancer therapies. Hypoxia is a prominent characteristic of the solid tumor microenvironment. The transcription factor hypoxia-inducible factor-1α (HIF-1α) is an important mediator of hypoxic response of tumor cells that modulates the expression of specific genes involved in tumor immunosuppression. Using a 4T1 breast cancer model, we show that in vivo administration of PX-478, an inhibitor of oxygen-sensitive HIF-1α, led to reduced expression of Foxp3 and VEGF transcript and/or protein, molecules that are directly controlled by HIF-1. When combined with dendritic cell (DC)-based vaccination, HIF-1α inhibition resulted in an augmented cytotoxic T lymphocyte effector function, improved proliferation status of T cells, increased production of inflammatory cytokine IFN-γ, as well as reduced regulatory function of T cells in association with slower tumor growth. Taken together, our findings indicate that the use of HIF-1α inhibition provides an immune adjuvant activity, thereby improves the efficacy of tumor antigen-based DC vaccine.

Small Molecule-Mediated Anti-Cancer Therapy via Hypoxia Inducible Factor-1 Blockade

Despite reservations regarding potential toxicities, small molecule-mediated blockade of the hypoxia-inducible factor-1 transcription factor has emerged as a viable anti-cancer strategy in vivo. Recent experiments by Welsh et al. revealed unprecedented anti-tumor responses of various aggressive solid tumors to the HIF-1-inhibitory small molecule drug PX-478. Compared with other anti-cancer drugs, PX-478 had markedly improved regression, growth delay and log10 cell kill profiles, particularly against large tumors that are normally refractory to small molecule drug therapy. Importantly, pharmacokinetic and toxicity profiles were within acceptable limits, providing rationale for the clinical development of HIF-1 inhibitors in general. Though the mechanism of action for PX-478 is not completely understood, inhibition of glycolysis rather than angiogenesis appeared to be the primary mode of anti-cancer activity.

Chronic hyperpigmentation from a heated mustard compress burn: a case report

This is a case study of a woman who sustained a second-degree, partial-thickness burn of the midchest and medial breast distribution after the application of a heated mustard compress as a naturopathic remedy for a recent bout of pneumonia. This case study demonstrates the potential for hyperpigmentation and hypertrophic scarring associated with heated mustard burns. A photograph of the presenting burn with the region of hyperpigmentation 3 days after the injury is provided.

Antitumor effects of an antibody-carboxypeptidase G2 conjugate in combination with a benzoic acid mustard prodrug

The F(ab')2 fragment of the antitumor monoclonal antibody, A5B7, was covalently linked to the bacterial enzyme carboxypeptidase G2 (CPG2). The resulting conjugate was used in combination with a prodrug of a benzoic acid mustard alkylating agent to treat human colon tumor xenografts in a two-step targeting strategy, antibody-directed enzyme prodrug therapy (ADEPT). The prodrug, 4-[(2-chloroethyl) (2-mesyloxyethyl)amino]-benzoyl-L-glutamic acid is rapidly converted by CPG2 to a drug that is at least 15x more toxic in vitro against LS174T colorectal tumor cells than the prodrug. Optimal tumor/blood ratios of the A5B7-CPG2 were achieved 72 h after administration of the conjugate to athymic mice bearing established LS174T tumor xenografts. Significant antitumor activity was seen in LS174T tumor-bearing mice treated with the conjugate followed 3 d later by the prodrug. In contrast, prodrug, conjugate, or active drug alone did not result in any antitumor activity in this tumor model. These studies demonstrate the advantage of a two-step ADEPT system for the treatment of colorectal cancer.

[Treatment of psoriasis with dichlorodiethyl sulfide]

A report is given of the use of dichlorodiethyl-sulfide (ypérite) in ointment form in a concentration of 1: 20,000 in the treatment of psoriasis. The effect of the treatment was followed in 59 patients. Healing or marked improvement occurred in 44. In in-patients the average duration of treatment was 16 days and in out-patients 48 days. When compared with other methods of treatment the method of application is very simple and its effect rapid. So that with a shorter average duration of treatment a higher percentage of patients is healed.

Phase II trail of PCNU in refractory advanced breast cancer

An evaluation of PCNU was carried out in 28 patients with extensively treated refractory breast cancer. The starting dose was 60 mg/m2 in 13 patients and 90 mg/m2 in 15 patients given intravenously every 6 weeks. The major side effect was myelosuppression, manifested mainly as thrombocytopenia. Nonhematologic side effects were minimal, consisting mainly of transient nausea. One mixed response was seen. Four patients had stable disease. PCNU demonstrated limited activity in advanced breast cancer and was not effective in the treatment of central nervous system metastases.

Comparative pharmacokinetics of 1-(2-chloroethyl)-3-(2,6-dioxo-1-piperidyl)-1-nitrosourea in rats and patients and extrapolation to clinical trials

The plasma pharmacokinetics of 1-(2-chloroethyl)-3-(2,6-dioxo-1-piperidyl)1-nitrosourea (PCNU) were determined in ambulatory rats and in patients receiving PCNU chemotherapy in Phase 1 and II studies. After derivativization to the methyl carbamate, both rat and human PCNU plasma levels were measured by gas chromatography-mass spectrometry. Comparison of the tolerated dose levels and pharmacokinetics of PCNU to the values determined for 1,3-bis(2-chloroethyl)-1-nitrosourea in humans indicated that PCNU has a lower plasma drug area under the curve at equitoxic doses. We conclude that PCNU may show less clinical efficacy than 1,3-bis(2-chloroethyl)-1-nitrosourea in the treatment of solid tumors.

[Therapy-induced osteosarcoma in Hodgkin's disease]

Patients treated for Hodgkin's disease are exposed to increased risk for second malignancies, a fact which has been well documented in the past decade. Most of these malignancies are hematologic neoplasms, and only rarely have radiation induced sarcomas of the soft tissues or bone been reported. A case with a complication of this kind is described and the implications are discussed.

[Treatment of psoriasis vulgaris with external sulfur mustard gas with particular reference to its potential carcinogenic risk. III. Clinical and experimental studies on the extent of percutaneous and inhalational uptake of sulfur mustard gas]

Concerning the often discussed carcinogenic risk of psoriasis treatment with 0.005% S-mustard-vaseline (so-called Russian Ointment) -- especially by inhalation -- 19 patients were treated with a radioactive labeled S-mustard-ointment and examined. The patients' whole bodies were inuncted for 1--2 days with about 50 g of radioactive S-mustard vaseline (U14C, 3 muCi/g). Afterwards the radioactivity was determined in the patients' expired air, blood, urine, and in their surrounding air. In three patients punch biopsy material from normal and psoriatic skin was assayed for radioactivity after combustion. In the skin, radioactivity distinctly decreased from the epidermis (13.1 pCi/mg) to the subcutis (0.77 pCi/mg) without significant differences between normal skin and psoriatic lesions as confirmed by autoradiography. In all samples of air, body fluids and tissue, definitive amounts of radioactivity were found, which, however, were far below the US-American MAK-values. Between skin surface and shirt, the values varied from 1.5 to 13.7 nCi/20 l air, at a distance of 2 meters by 0.3 nCi/100 l air, in the breath by 0.5 nCi/20 l. The radioactivity decreased to 1/10 of the maximum values after 1--2 hours. In blood the activity was at the limit of detection and was parallelled by the activity of the urine. Generally, 1--7% of the radioactivity applied to the skin was eliminated with the urine within one week. Thus, the carcinogenic risk may be very low in the external S-mustard therapy of psoriasis and other skin diseases.

[Therapy of non-Hodgkin lymphomas]

The survey is introduced by references to the relations between special diagnostic findings and life expectancy. Also the contribution of the clinician to the diagnostics of the non-Hodgkin-lymphomas is dealt with. Five standpoints are to be regarded in the new management of chemotherapy: 1. The polychemotherapy is more effective than the monotherapy. 2. Massive-dose therapies of middle degree are more favourable than frequent, low-dosed cytostatic dosages. 3. Connection of the polychemotherapy with the radiotherapy in stage III and IV. 4. Particularly in the lymphomas with a high degree of malignancy polychemotherapy already in stage II following the radiation. 5. Especially intensive polychemotherapy in the lymphomas with a high degree of malignancy. The hitherto got findings in the polychemotherapy of the non-Hodgkin-lymphomas are reported. Here particularly the COP-scheme proved to be favourable, if necessary in connection with bleomycin, adriamycin or methotrexat; also BCNU or dakarbacin are possible. Own propositions, separated for lymphomas for low and high malignancy, respectively, take into consideration also the GDR-preparation Cytostasan.

[Therapy of lymphogranulomatosis]

A survey is given on the therapy of lymphogranulomatosis. Keystones of the treatment are radiotherapy, antineoplastic chemotherapy and supportive measures of treatment. A therapy referred to diagnosis and stages including a clinical and pathological staging proves to be necessary in every case. The initial treatment consists in a radiotherapy in the stages I, II and III A, in a polychemotherapy according to the scheme MOPP and COPP, respectively, or CVPP in the stages III B and IV as well as possibly in a combined treatment in histomorphologically unfavourable forms also already in the early stages. The problems of the MOPP alternative programmes in primary failures, of the programmes of the post-MOPP-therapy in secondary failures and recidivations as well as of the remission-keeping long-term therapy need a further clarification. It is referred to the dangers and side-effects of an aggressive radio- and chemotherapy.

Chemoimmunotherapy of cancer

The preparation of a series of water-soluble mustard haptens for chemoimmunotherapy of cancer is described. Preliminary screening data are given, indicating some activity against P388 lymphocytic leukemia for those compounds containing the most potent immunogenic functional groups.

Imidazole carboxamide (DTIC) in the treatment of advanced lymphomas. Efficacy of DTIC in cases which fail to respond to conventional chemotherupetic combinations

15 patients with malignant lymphomas (stage III B or IV) who had become resistant to previous combination chemotherapy were treated with DTIC. The drug was administered intravenously as a single agent in doses of 300 mg/m2 on 5 consecutive days, once a month. The results demonstrate good responses in Hodgkin's disease, while in non-Hodgkin's lymphomas only incomplete and short remissions or failures were recorded. The only untoward side effects were nausea, vomiting and pain in the vein during the injection.

Abnormal spleen scan following MOPP therapy in a patient with Hodgkin's disease: case report

A patient with Stage IV-A nodular sclerosing Hodgkin's disease is described who, at initial presentation, demonstrated an apparent large filling defect in the spleen by 99mTc-sulfur colloid scan. Following a 6-month course of MOPP therapy, the patient was clinically free of disease although the spleen scan remained unchanged. After laparotomy, the spleen was found to be entirely normal histologically.