Anti-Tumor Effects of Direct Current (DC) Application

Medical Hypotheses (1997) 49, pg 297-300
Targeting a key enzyme in cell growth: A novel therapy for cancer
http://www.cancer-treatment.net/TheArticlePg1.htm

Abstract --- The enzyme ribonucleotide reductase (RR) controls the synthesis of DNA precursors and thus plays a pivotal role in cell growth. Since the free-radical-containing active-site of this enzyme can be disabled by a lone electron, low-level direct electric current should have an inhibitory effect on RR and, thus, on uncontrolled cell proliferation. This hypothesis is strongly supported by the results of several cancer electrotherapy studies reported over the years.

Introduction
Cancer is uncontrolled cell growth. For a cell to divide, it must replicate its DNA strand. The building blocks of this strand are in short supply in a healthy, resting cell. However, the building blocks of a related molecule RNA are always in great abundance since RNA is needed for many cellular functions. When a cell is ready to divide, an enzyme called ribonucleotide reductase (RR) converts building blocks of RNA into those of DNA. The enzyme RR is, thus, pivotal for cell growth. Not surprisingly, the activity of this enzyme is tightly linked, much more than that of any other enzyme, to neoplastic transformation and progression (1).
A whole class of anti-cancer chemotherapeutic drugs, hydroxy-urea being best known, is aimed at blocking the enzyme RR (2). However, utility of such drugs is limited since inhibition of the enzymic activity is only partial and undesirable side-effects are many.

Hypothesis
A novel way of arresting the activity of this pivotal enzyme in cell growth is suggested by the fact that the active site of RR contains a stable tyrosyl free radical which is essential for its activity (13). Such free radicals can be neutralized/destroyed by free-floating electrons -- easily available in the form of direct electric current. Thus DC electrotherapy should result in inhibition of RR and cessation of malignant cell proliferation. Low-level surface DC electrotherapy would act selectively on cancerous growth since the concentration of the target enzyme RR is exponentially higher in cancerous cells, as compared to healthy quiescent cells (1). Metastasized cancer should also be treatable by direct current electrotherapy since even in the metastatic state, irrespective of the organ micro-environment, the biochemical mechanism of cell division involving the enzyme RR, remains the same.

Experimental evidence
The connection between low-level DC electrotherapy and deactivation of enzyme RR is being proposed for the first time. However, use of low-level direct electric currents to treat tumor -- without any clear understanding of the underlying mechanism -- has been reported in scientific literature about ten times during the last four decades (4-13). Three of these papers - the last one in 1985 - reported very encouraging results. For example, in some experiments, there was total regression in 60% of mice (4), an average of 88% tumor necrosis [destruction] in hamsters (5), and 98% reduction in tumor mass, also in hamsters (7). (It is strange that none of these studies had any proper follow-ups.) The outcome of other studies was less positive -- almost certainly due to poor choice of parameters.

Following is a summary of these ten reports. (The electrode near the tumor is termed as 'active', the other one being called 'passive'.)

1. Humphrey et al, 1959 (4)
ACTIVE Electrode: Copper or Zinc plate with saline-solution-saturated sponge on unbroken skin over tumor.
PASSIVE Electrode: Same, over ventral area.
BEST RESULTS (Total regression in 60% mice): at cathode, with 3 milliamperes at 3 V, 4.8 hours per day for 21 days.

2. Schauble et al, 1977 (5)
ACTIVE Electrode: Silicone covered steel needle - exposed tip implanted.
PASSIVE Electrode: Wire-mesh with electrode paste and saline-dampened sponge - over chest skin.
BEST RESULTS (88% Necrosis): at positive electrode with 3 mA at 1.5 V, 1 hour per day for 4 days.
NOTE: Necrosis was also observed when active electrode was made negative.

3. Habal 1980 (6)
Poor results with 0.5 æA at 1.5 V, for 12 days continuous, using an implanted device.

4. David et al, 1985 (7)
ACTIVE Electrode: Silicone covered Steel or Platinum-Iridium (70:30) needle - exposed tip implanted.
PASSIVE Electrode: Aluminum foil plate with conducting paste - over shaved underbelly.
BEST RESULTS (98% Reduction in tumor mass): at either electrode, with 2.4 mA at less than 3 V, for 1 hour per day for 5 days.

5. Marino and Morris et al, 1986 (8)
Both Electrodes ACTIVE: Insulated Platinum - except for the implanted tips - at foci of tumor.
BEST RESULTS (Total regression in 43% of primary tumors): with 2 mA at about 3 V, 1 hour per day for 3 intermittent days.

6. Morris and Marino et al, 1992 (9)
Both Electrodes ACTIVE: Platinum needles - implanted in tumor.
BEST RESULTS (Reduction in tumor mass without improved survival): with 20 mA at 8-10 V, for 15 minutes once.

7. Miklavki et al, 1993 (10)
ACTIVE Electrode: Platinum-Iridium (90:10), Gold, Silver or Titanium needle tip implanted.
PASSIVE Electrode: Same, placed subcutaneously the whole length, near tumor.
BEST RESULTS (About 70% necrosis): at cathode, with 0.6 mA at unspecified volts, for 1 hour once.
NOTE: "Field" electrotherapy, by placing both electrodes subcutaneously for their entire length, on either side of tumor, also produced similar necrosis.

8. Griffin et al, 1994 (11)
ACTIVE Electrode: Gold needle - implanted.
PASSIVE Electrode: Copper plate with conducting gel - beneath the animal.
BEST RESULTS (Regression proportional to charge passed): at anode, with 1-4 mA at 1-16 V, for 30-90 min. once.

9. Taylor et al, 1994 (12)
ACTIVE Electrode: 4 parallel brass plates, vertically mounted, in a specially designed oesophageal tube.
PASSIVE Electrode: Large plate with saline-soaked pad on human patients back.
BEST RESULTS (Oesophagus tumor of one patient regressed completely at the primary site): with 20 mA at 7 V, at each of four anodes, for 1 hour. Three treatments over 4+1/2 month period.

10. Miklavki et al, 1994 (13)
ACTIVE/PASSIVE Electrodes: Gold needles, placed subcutaneously the whole length, on either side of tumor.
BEST RESULTS (Tumor growth slowed by a factor of 3): with 1.0 mA at unspecified volts, for 1 hour, applied once.
NOTE: No correlation was observed between the amount of deposited electrode material (gold) and anti-tumor effect.

Discussion and conclusion
Both positive and negative results of the published low-level electrotherapy studies can be adequately explained by the posited enzyme-mediated mechanism. Various aspects of these reports is being discussed in these sections:

Positioning & Polarity of Electrodes
If deactivation of the enzyme RR is the dominant mechanism underlying the efficacy of electrotherapy, then it should not matter whether electrodes are implanted or on the surface -- as long as the tumor is in the path of the current. Only in study #1 (4) were both electrodes placed on unbroken skin, and it reported one of the better results. Beside being non-invasive, surface electrodes also minimize electrochemistry and its attendant toxicity. Similar reasoning would suggest that the polarity of the electrodes is inconsequential. Almost all electrotherapy studies where beneficial results were obtained, confirm this. Results of "field" electrotherapy experiments, where electrodes were implanted on either side of tumor (10,13) also show that polarity of electrodes is immaterial, and that electrode-electrolyte interactions are of little significance.

Electrode Metal Dissolution
If the primary mechanism of electrotherapy involves inhibition of enzyme RR, then electrode metal deposition should have little or no influence on the beneficial outcome. Study 10 (13) has clearly shown that this is so. The fact that different electrode materials produce very similar results, further indicates that electrodes act merely as electron conductors. Thus, virtually all the observed facts are in accord with the proposed mechanism involving the deactivation of the free-radical-containing active site of RR. Furthermore, a recent experiment has shown that the concentration of enzyme RR decreases and cell growth ceases when direct electric current is passed through the tumor (15). The proposed hypothesis, thus, is on the verge of being proved.
This novel way of arresting cell growth can be the foundation of a cancer therapy that is non-toxic, non-invasive, site-specific, low-cost and easy to administer. The current cancer treatments are called "slash, burn & poison" by oncologists themselves, and are mostly empirical in nature. The gentle electrotherapy, on the other hand, would be deductively scientific with potential to cure most cancers.

References
1. Weber, G. (1983) Biochemical strategy of cancer cells and the design of chemotherapy. Cancer Res. 43, 3466-3492.
2. Cory, J.G., and Cory, A.H. (1989) Inhibition of ribonucleoside diphosphate reductase activity. International encyclopedia of pharmacology and therapeutics. New York: Pergamon Press, pp 1-16.
3. Graslund, A., Ehrenberg, A., and Thelander, L. (1982) Characterization of the free-radical of mammalian ribonucleotide reductase. J. Biol. Chem. 257, 5711-5715.
4. Humphrey, C.E., and Seal, E.H. (1959) Biophysical Approach Toward Tumor Regression in Mice. Science 130, 388-390.
5. Schauble, Habal, and Gullick, (1977) Inhibition of experimental tumor growth in hamsters by small direct currents. Arch. Pathol. Lab. Med. 101, 294-297.
6. Habal, M.B. (1980) Effect of applied d.c. currents on experimental tumor growth in rats. J. Biomed. Mat. Res. 14, 789-801.
7. David, Absolom, Smith, Gams, and Herbert, (1985) Effect of low level direct current on in vivo tumor growth in hamsters. Cancer Res. 45, 5625-5631.
8. Marino, A.A., Morris, D., and Arnold, T. (1986) Electric treatment of lewis lung carcinoma in mice. J. Surg. Res. 41, 198-201.
9. Morris, D.M., Marino, A.A., and Gonzalez, E. (1992) Electrochemical modification of tumor growth in mice. J. Surg. Res. 53, 306-309.
10. Miklavki, D., Sersa, G., Kryzanowski, M., Novakovi, S., Bobanovi, Golouh, and Vodovnik, (1993) Tumor treatment by direct electric current - tumor temperature and pH, electrode matteriial and configuration. Bioelectro. B. 30, 209-220.
11. Griffin, D.T., Dodd, N.J.F., Moore, J.V., Pullan, B.R., and Taylor, (1994) The effects of low-level direct current therapy on a preclinical mammary carcinoma: tumor regression and systemic biochemical sequelae. Br. J. Cancer 69, 875-878.
12. Taylor, T.V., Engler, P., Pullan, B.R., and Holt, S. (1994) Ablation of neoplasia by direct current. Br. J. Cancer 70, 342-345.
13. Miklavki, D., Fajgelj, A., and Sersa, G. (1994) Tumor treatment by direct electric current: electrode material deposition. Bioelectro. B. 35, 93-97.
14. Nordenstrom, B.E.W. (1985) Electrochemical treatment of cancer. Ann. Radiol., 43, 84-87.
15. Yen, Y., and Chou, C.K., City of Hope Medical Center, Duarte, CA., USA (personal communication).

Michael´s Comments: The referenced studies were able to achieve 3mA of electrical current with low voltage (~3v) because the electrodes were directly opposite tumors on small mice. On larger animals and humans it is certain that more voltage will be necessary to achieve 3mA current because more living tissue between electrodes presents more resistance. The formula for determining current (I= V/R) shows that with more resistance, more voltage is necessary to achieve the same current. Therefore, our DC Electrifier uses 36 volts as the source which may be necessary to achieve 3ma current. But it is the current which does the work, not the voltage. The current can be set to 5mA maximum or adjusted lower if necessary to be comfortable.